예제 #1
0
        public void testLargeRates()
        {
            // Testing degenerate collared coupon

            CommonVars vars = new CommonVars();

            /* A vanilla floating leg and a capped floating leg with strike
             * equal to 100 and floor equal to 0 must have (about) the same NPV
             * (depending on variance: option expiry and volatility)
             */

            List <double?> caps      = new InitializedList <double?>(vars.length, 100.0);
            List <double?> floors    = new InitializedList <double?>(vars.length, 0.0);
            double         tolerance = 1e-10;

            // fixed leg with zero rate
            List <CashFlow> fixedLeg    = vars.makeFixedLeg(vars.startDate, vars.length);
            List <CashFlow> floatLeg    = vars.makeFloatingLeg(vars.startDate, vars.length);
            List <CashFlow> collaredLeg = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors, vars.volatility);

            IPricingEngine engine     = new DiscountingSwapEngine(vars.termStructure);
            Swap           vanillaLeg = new Swap(fixedLeg, floatLeg);
            Swap           collarLeg  = new Swap(fixedLeg, collaredLeg);

            vanillaLeg.setPricingEngine(engine);
            collarLeg.setPricingEngine(engine);
            double npvVanilla = vanillaLeg.NPV();
            double npvCollar  = collarLeg.NPV();

            if (Math.Abs(npvVanilla - npvCollar) > tolerance)
            {
                QAssert.Fail("Lenght: " + vars.length + " y" + "\n" +
                             "Volatility: " + vars.volatility * 100 + "%\n" +
                             "Notional: " + vars.nominal + "\n" +
                             "Vanilla floating leg NPV: " + vanillaLeg.NPV()
                             + "\n" +
                             "Collared floating leg NPV (strikes 0 and 100): "
                             + collarLeg.NPV()
                             + "\n" +
                             "Diff: " + Math.Abs(vanillaLeg.NPV() - collarLeg.NPV()));
            }
        }
예제 #2
0
        public void testDecomposition()
        {
            // Testing collared coupon against its decomposition...

            CommonVars vars = new CommonVars();

            double        tolerance = 1e-10;
            double        npvVanilla, npvCappedLeg, npvFlooredLeg, npvCollaredLeg, npvCap, npvFloor, npvCollar;
            double        error;
            double        floorstrike = 0.05;
            double        capstrike   = 0.10;
            List <double> caps        = new InitializedList <double>(vars.length, capstrike);
            List <double> caps0       = new List <double>();
            List <double> floors      = new InitializedList <double>(vars.length, floorstrike);
            List <double> floors0     = new List <double>();
            double        gearing_p   = 0.5;
            double        spread_p    = 0.002;
            double        gearing_n   = -1.5;
            double        spread_n    = 0.12;
            // fixed leg with zero rate
            List <CashFlow> fixedLeg = vars.makeFixedLeg(vars.startDate, vars.length);
            // floating leg with gearing=1 and spread=0
            List <CashFlow> floatLeg = vars.makeYoYLeg(vars.startDate, vars.length);
            // floating leg with positive gearing (gearing_p) and spread<>0
            List <CashFlow> floatLeg_p = vars.makeYoYLeg(vars.startDate, vars.length, gearing_p, spread_p);
            // floating leg with negative gearing (gearing_n) and spread<>0
            List <CashFlow> floatLeg_n = vars.makeYoYLeg(vars.startDate, vars.length, gearing_n, spread_n);
            // Swap with null fixed leg and floating leg with gearing=1 and spread=0
            Swap vanillaLeg = new Swap(fixedLeg, floatLeg);
            // Swap with null fixed leg and floating leg with positive gearing and spread<>0
            Swap vanillaLeg_p = new Swap(fixedLeg, floatLeg_p);
            // Swap with null fixed leg and floating leg with negative gearing and spread<>0
            Swap vanillaLeg_n = new Swap(fixedLeg, floatLeg_n);

            IPricingEngine engine = new DiscountingSwapEngine(vars.nominalTS);

            vanillaLeg.setPricingEngine(engine); // here use the autoset feature
            vanillaLeg_p.setPricingEngine(engine);
            vanillaLeg_n.setPricingEngine(engine);

            // CAPPED coupon - Decomposition of payoff
            // Payoff = Nom * Min(rate,strike) * accrualperiod =
            // = Nom * [rate + Min(0,strike-rate)] * accrualperiod =
            // = Nom * rate * accrualperiod - Nom * Max(rate-strike,0) * accrualperiod =
            // = VanillaFloatingLeg - Call
            //

            int whichPricer = 0;

            // Case gearing = 1 and spread = 0
            List <CashFlow> cappedLeg = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length,
                                                                  caps, floors0, vars.volatility);
            Swap capLeg = new Swap(fixedLeg, cappedLeg);

            capLeg.setPricingEngine(engine);
            YoYInflationCap cap = new YoYInflationCap(floatLeg, new List <double>()
            {
                capstrike
            });

            cap.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla   = vanillaLeg.NPV();
            npvCappedLeg = capLeg.NPV();
            npvCap       = cap.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla - npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Capped Leg: gearing=1, spread=0%, strike=" + capstrike * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                             "  Diff: " + error);
            }

            // gearing = 1 and spread = 0
            // FLOORED coupon - Decomposition of payoff
            // Payoff = Nom * Max(rate,strike) * accrualperiod =
            // = Nom * [rate + Max(0,strike-rate)] * accrualperiod =
            // = Nom * rate * accrualperiod + Nom * Max(strike-rate,0) * accrualperiod =
            // = VanillaFloatingLeg + Put
            //

            List <CashFlow> flooredLeg = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length,
                                                                   caps0, floors, vars.volatility);
            Swap floorLeg = new Swap(fixedLeg, flooredLeg);

            floorLeg.setPricingEngine(engine);
            YoYInflationFloor floor = new YoYInflationFloor(floatLeg, new List <double>()
            {
                floorstrike
            });

            floor.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvFlooredLeg = floorLeg.NPV();
            npvFloor      = floor.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla + npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("YoY Floored Leg: gearing=1, spread=0%, strike=" + floorstrike * 100 +
                             "%\n" +
                             "  Floored Floating Leg NPV: " + npvFlooredLeg + "\n" +
                             "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor) + "\n" +
                             "  Diff: " + error);
            }

            // gearing = 1 and spread = 0
            // COLLARED coupon - Decomposition of payoff
            // Payoff = Nom * Min(strikem,Max(rate,strikeM)) * accrualperiod =
            // = VanillaFloatingLeg - Collar
            //

            List <CashFlow> collaredLeg = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length,
                                                                    caps, floors, vars.volatility);
            Swap collarLeg = new Swap(fixedLeg, collaredLeg);

            collarLeg.setPricingEngine(engine);
            YoYInflationCollar collar = new YoYInflationCollar(floatLeg,
                                                               new List <double>()
            {
                capstrike
            },
                                                               new List <double>()
            {
                floorstrike
            });

            collar.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvCollaredLeg = collarLeg.NPV();
            npvCollar      = collar.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Collared Leg: gearing=1, spread=0%, strike=" +
                             floorstrike * 100 + "% and " + capstrike * 100 + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar) + "\n" +
                             "  Diff: " + error);
            }

            // gearing = a and spread = b
            // CAPPED coupon - Decomposition of payoff
            // Payoff
            // = Nom * Min(a*rate+b,strike) * accrualperiod =
            // = Nom * [a*rate+b + Min(0,strike-a*rate-b)] * accrualperiod =
            // = Nom * a*rate+b * accrualperiod + Nom * Min(strike-b-a*rate,0) * accrualperiod
            // --> If a>0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg - Call(a*rate+b,strike)
            // --> If a<0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg + Nom * Min(strike-b+|a|*rate+,0) * accrualperiod =
            // = VanillaFloatingLeg + Put(|a|*rate+b,strike)
            //

            // Positive gearing
            List <CashFlow> cappedLeg_p = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps, floors0,
                                                                    vars.volatility, gearing_p, spread_p);
            Swap capLeg_p = new Swap(fixedLeg, cappedLeg_p);

            capLeg_p.setPricingEngine(engine);
            YoYInflationCap cap_p = new YoYInflationCap(floatLeg_p, new List <double>()
            {
                capstrike
            });

            cap_p.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla   = vanillaLeg_p.NPV();
            npvCappedLeg = capLeg_p.NPV();
            npvCap       = cap_p.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla - npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Capped Leg: gearing=" + gearing_p + ", " +
                             "spread= " + spread_p * 100 +
                             "%, strike=" + capstrike * 100 + "%, " +
                             "effective strike= " + (capstrike - spread_p) / gearing_p * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  Vanilla Leg NPV: " + npvVanilla + "\n" +
                             "  Cap NPV: " + npvCap + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                             "  Diff: " + error);
            }

            // Negative gearing
            List <CashFlow> cappedLeg_n = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps, floors0,
                                                                    vars.volatility, gearing_n, spread_n);
            Swap capLeg_n = new Swap(fixedLeg, cappedLeg_n);

            capLeg_n.setPricingEngine(engine);
            YoYInflationFloor floor_n = new YoYInflationFloor(floatLeg, new List <double>()
            {
                (capstrike - spread_n) / gearing_n
            });

            floor_n.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla   = vanillaLeg_n.NPV();
            npvCappedLeg = capLeg_n.NPV();
            npvFloor     = floor_n.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla + gearing_n * npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Capped Leg: gearing=" + gearing_n + ", " +
                             "spread= " + spread_n * 100 +
                             "%, strike=" + capstrike * 100 + "%, " +
                             "effective strike= " + ((capstrike - spread_n) / gearing_n * 100) +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  npv Vanilla: " + npvVanilla + "\n" +
                             "  npvFloor: " + npvFloor + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla + gearing_n * npvFloor) + "\n" +
                             "  Diff: " + error);
            }

            // gearing = a and spread = b
            // FLOORED coupon - Decomposition of payoff
            // Payoff
            // = Nom * Max(a*rate+b,strike) * accrualperiod =
            // = Nom * [a*rate+b + Max(0,strike-a*rate-b)] * accrualperiod =
            // = Nom * a*rate+b * accrualperiod + Nom * Max(strike-b-a*rate,0) * accrualperiod
            // --> If a>0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg + Put(a*rate+b,strike)
            // --> If a<0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg + Nom * Max(strike-b+|a|*rate+,0) * accrualperiod =
            // = VanillaFloatingLeg - Call(|a|*rate+b,strike)
            //

            // Positive gearing
            List <CashFlow> flooredLeg_p1 = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps0, floors,
                                                                      vars.volatility, gearing_p, spread_p);
            Swap floorLeg_p1 = new Swap(fixedLeg, flooredLeg_p1);

            floorLeg_p1.setPricingEngine(engine);
            YoYInflationFloor floor_p1 = new YoYInflationFloor(floatLeg_p, new List <double>()
            {
                floorstrike
            });

            floor_p1.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla    = vanillaLeg_p.NPV();
            npvFlooredLeg = floorLeg_p1.NPV();
            npvFloor      = floor_p1.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla + npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Floored Leg: gearing=" + gearing_p + ", "
                             + "spread= " + spread_p * 100 + "%, strike=" + floorstrike * 100 + "%, "
                             + "effective strike= " + (floorstrike - spread_p) / gearing_p * 100
                             + "%\n" +
                             "  Floored Floating Leg NPV: " + npvFlooredLeg
                             + "\n" +
                             "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor)
                             + "\n" +
                             "  Diff: " + error);
            }
            // Negative gearing
            List <CashFlow> flooredLeg_n = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps0, floors,
                                                                     vars.volatility, gearing_n, spread_n);
            Swap floorLeg_n = new Swap(fixedLeg, flooredLeg_n);

            floorLeg_n.setPricingEngine(engine);
            YoYInflationCap cap_n = new YoYInflationCap(floatLeg, new List <double>()
            {
                (floorstrike - spread_n) / gearing_n
            });

            cap_n.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla    = vanillaLeg_n.NPV();
            npvFlooredLeg = floorLeg_n.NPV();
            npvCap        = cap_n.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla - gearing_n * npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Capped Leg: gearing=" + gearing_n + ", " +
                             "spread= " + spread_n * 100 +
                             "%, strike=" + floorstrike * 100 + "%, " +
                             "effective strike= " + (floorstrike - spread_n) / gearing_n * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvFlooredLeg + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - gearing_n * npvCap) + "\n" +
                             "  Diff: " + error);
            }
            // gearing = a and spread = b
            // COLLARED coupon - Decomposition of payoff
            // Payoff = Nom * Min(caprate,Max(a*rate+b,floorrate)) * accrualperiod
            // --> If a>0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg - Collar(a*rate+b, floorrate, caprate)
            // --> If a<0 (assuming positive effective strike):
            // Payoff = VanillaFloatingLeg + Collar(|a|*rate+b, caprate, floorrate)
            //
            // Positive gearing
            List <CashFlow> collaredLeg_p = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps, floors,
                                                                      vars.volatility, gearing_p, spread_p);
            Swap collarLeg_p1 = new Swap(fixedLeg, collaredLeg_p);

            collarLeg_p1.setPricingEngine(engine);
            YoYInflationCollar collar_p = new YoYInflationCollar(floatLeg_p,
                                                                 new List <double>()
            {
                capstrike
            },
                                                                 new List <double>()
            {
                floorstrike
            });

            collar_p.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla     = vanillaLeg_p.NPV();
            npvCollaredLeg = collarLeg_p1.NPV();
            npvCollar      = collar_p.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Collared Leg: gearing=" + gearing_p + ", "
                             + "spread= " + spread_p * 100 + "%, strike="
                             + floorstrike * 100 + "% and " + capstrike * 100
                             + "%, "
                             + "effective strike=" + (floorstrike - spread_p) / gearing_p * 100
                             + "% and " + (capstrike - spread_p) / gearing_p * 100
                             + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg
                             + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar)
                             + "\n" +
                             "  Diff: " + error);
            }
            // Negative gearing
            List <CashFlow> collaredLeg_n = vars.makeYoYCapFlooredLeg(whichPricer, vars.startDate, vars.length, caps, floors,
                                                                      vars.volatility, gearing_n, spread_n);
            Swap collarLeg_n1 = new Swap(fixedLeg, collaredLeg_n);

            collarLeg_n1.setPricingEngine(engine);
            YoYInflationCollar collar_n = new YoYInflationCollar(floatLeg,
                                                                 new List <double>()
            {
                (floorstrike - spread_n) / gearing_n
            },
                                                                 new List <double>()
            {
                (capstrike - spread_n) / gearing_n
            });

            collar_n.setPricingEngine(vars.makeEngine(vars.volatility, whichPricer));
            npvVanilla     = vanillaLeg_n.NPV();
            npvCollaredLeg = collarLeg_n1.NPV();
            npvCollar      = collar_n.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - gearing_n * npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nYoY Collared Leg: gearing=" + gearing_n + ", "
                             + "spread= " + spread_n * 100 + "%, strike="
                             + floorstrike * 100 + "% and " + capstrike * 100
                             + "%, "
                             + "effective strike=" + (floorstrike - spread_n) / gearing_n * 100
                             + "% and " + (capstrike - spread_n) / gearing_n * 100
                             + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg
                             + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - gearing_n * npvCollar)
                             + "\n" +
                             "  Diff: " + error);
            }
            // remove circular refernce
            vars.hy.linkTo(null);
        }
예제 #3
0
        public void testDecomposition()
        {
            // Testing collared coupon against its decomposition

            CommonVars vars = new CommonVars();

            double         tolerance = 1e-12;
            double         npvVanilla, npvCappedLeg, npvFlooredLeg, npvCollaredLeg, npvCap, npvFloor, npvCollar;
            double         error;
            double         floorstrike = 0.05;
            double         capstrike   = 0.10;
            List <double?> caps        = new InitializedList <double?>(vars.length, capstrike);
            List <double?> caps0       = new List <double?>();
            List <double?> floors      = new InitializedList <double?>(vars.length, floorstrike);
            List <double?> floors0     = new List <double?>();
            double         gearing_p   = 0.5;
            double         spread_p    = 0.002;
            double         gearing_n   = -1.5;
            double         spread_n    = 0.12;
            // fixed leg with zero rate
            List <CashFlow> fixedLeg = vars.makeFixedLeg(vars.startDate, vars.length);
            // floating leg with gearing=1 and spread=0
            List <CashFlow> floatLeg = vars.makeFloatingLeg(vars.startDate, vars.length);
            // floating leg with positive gearing (gearing_p) and spread<>0
            List <CashFlow> floatLeg_p = vars.makeFloatingLeg(vars.startDate, vars.length, gearing_p, spread_p);
            // floating leg with negative gearing (gearing_n) and spread<>0
            List <CashFlow> floatLeg_n = vars.makeFloatingLeg(vars.startDate, vars.length, gearing_n, spread_n);
            // Swap with null fixed leg and floating leg with gearing=1 and spread=0
            Swap vanillaLeg = new Swap(fixedLeg, floatLeg);
            // Swap with null fixed leg and floating leg with positive gearing and spread<>0
            Swap vanillaLeg_p = new Swap(fixedLeg, floatLeg_p);
            // Swap with null fixed leg and floating leg with negative gearing and spread<>0
            Swap vanillaLeg_n = new Swap(fixedLeg, floatLeg_n);

            IPricingEngine engine = new DiscountingSwapEngine(vars.termStructure);

            vanillaLeg.setPricingEngine(engine);
            vanillaLeg_p.setPricingEngine(engine);
            vanillaLeg_n.setPricingEngine(engine);

            /* CAPPED coupon - Decomposition of payoff
             * Payoff = Nom * Min(rate,strike) * accrualperiod =
             *       = Nom * [rate + Min(0,strike-rate)] * accrualperiod =
             *       = Nom * rate * accrualperiod - Nom * Max(rate-strike,0) * accrualperiod =
             *       = VanillaFloatingLeg - Call
             */

            // Case gearing = 1 and spread = 0
            List <CashFlow> cappedLeg = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors0, vars.volatility);
            Swap            capLeg    = new Swap(fixedLeg, cappedLeg);

            capLeg.setPricingEngine(engine);
            Cap cap = new Cap(floatLeg, new InitializedList <double>(1, capstrike));

            cap.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla   = vanillaLeg.NPV();
            npvCappedLeg = capLeg.NPV();
            npvCap       = cap.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla - npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nCapped Leg: gearing=1, spread=0%, strike=" + capstrike * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                             "  Diff: " + error);
            }

            /* gearing = 1 and spread = 0
             * FLOORED coupon - Decomposition of payoff
             * Payoff = Nom * Max(rate,strike) * accrualperiod =
             *       = Nom * [rate + Max(0,strike-rate)] * accrualperiod =
             *       = Nom * rate * accrualperiod + Nom * Max(strike-rate,0) * accrualperiod =
             *       = VanillaFloatingLeg + Put
             */

            List <CashFlow> flooredLeg = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps0, floors, vars.volatility);
            Swap            floorLeg   = new Swap(fixedLeg, flooredLeg);

            floorLeg.setPricingEngine(engine);
            Floor floor = new Floor(floatLeg, new InitializedList <double>(1, floorstrike));

            floor.setPricingEngine(vars.makeEngine(vars.volatility));
            npvFlooredLeg = floorLeg.NPV();
            npvFloor      = floor.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla + npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("Floored Leg: gearing=1, spread=0%, strike=" + floorstrike * 100 +
                             "%\n" +
                             "  Floored Floating Leg NPV: " + npvFlooredLeg + "\n" +
                             "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor) + "\n" +
                             "  Diff: " + error);
            }

            /* gearing = 1 and spread = 0
             * COLLARED coupon - Decomposition of payoff
             * Payoff = Nom * Min(strikem,Max(rate,strikeM)) * accrualperiod =
             *       = VanillaFloatingLeg - Collar
             */

            List <CashFlow> collaredLeg = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors, vars.volatility);
            Swap            collarLeg   = new Swap(fixedLeg, collaredLeg);

            collarLeg.setPricingEngine(engine);
            Collar collar = new Collar(floatLeg, new InitializedList <double>(1, capstrike),
                                       new InitializedList <double>(1, floorstrike));

            collar.setPricingEngine(vars.makeEngine(vars.volatility));
            npvCollaredLeg = collarLeg.NPV();
            npvCollar      = collar.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nCollared Leg: gearing=1, spread=0%, strike=" +
                             floorstrike * 100 + "% and " + capstrike * 100 + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar) + "\n" +
                             "  Diff: " + error);
            }

            /* gearing = a and spread = b
             * CAPPED coupon - Decomposition of payoff
             * Payoff
             * = Nom * Min(a*rate+b,strike) * accrualperiod =
             * = Nom * [a*rate+b + Min(0,strike-a*rate-b)] * accrualperiod =
             * = Nom * a*rate+b * accrualperiod + Nom * Min(strike-b-a*rate,0) * accrualperiod
             * --> If a>0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg - Call(a*rate+b,strike)
             * --> If a<0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg + Nom * Min(strike-b+|a|*rate+,0) * accrualperiod =
             *          = VanillaFloatingLeg + Put(|a|*rate+b,strike)
             */

            // Positive gearing
            List <CashFlow> cappedLeg_p = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors0,
                                                                 vars.volatility, gearing_p, spread_p);
            Swap capLeg_p = new Swap(fixedLeg, cappedLeg_p);

            capLeg_p.setPricingEngine(engine);
            Cap cap_p = new Cap(floatLeg_p, new InitializedList <double>(1, capstrike));

            cap_p.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla   = vanillaLeg_p.NPV();
            npvCappedLeg = capLeg_p.NPV();
            npvCap       = cap_p.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla - npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nCapped Leg: gearing=" + gearing_p + ", " +
                             "spread= " + spread_p * 100 +
                             "%, strike=" + capstrike * 100 + "%, " +
                             "effective strike= " + (capstrike - spread_p) / gearing_p * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  Vanilla Leg NPV: " + npvVanilla + "\n" +
                             "  Cap NPV: " + npvCap + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                             "  Diff: " + error);
            }

            // Negative gearing
            List <CashFlow> cappedLeg_n = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors0,
                                                                 vars.volatility, gearing_n, spread_n);
            Swap capLeg_n = new Swap(fixedLeg, cappedLeg_n);

            capLeg_n.setPricingEngine(engine);
            Floor floor_n = new Floor(floatLeg, new InitializedList <double>(1, (capstrike - spread_n) / gearing_n));

            floor_n.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla   = vanillaLeg_n.NPV();
            npvCappedLeg = capLeg_n.NPV();
            npvFloor     = floor_n.NPV();
            error        = Math.Abs(npvCappedLeg - (npvVanilla + gearing_n * npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("\nCapped Leg: gearing=" + gearing_n + ", " +
                             "spread= " + spread_n * 100 +
                             "%, strike=" + capstrike * 100 + "%, " +
                             "effective strike= " + (capstrike - spread_n) / gearing_n * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                             "  npv Vanilla: " + npvVanilla + "\n" +
                             "  npvFloor: " + npvFloor + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla + gearing_n * npvFloor) + "\n" +
                             "  Diff: " + error);
            }

            /* gearing = a and spread = b
             * FLOORED coupon - Decomposition of payoff
             * Payoff
             * = Nom * Max(a*rate+b,strike) * accrualperiod =
             * = Nom * [a*rate+b + Max(0,strike-a*rate-b)] * accrualperiod =
             * = Nom * a*rate+b * accrualperiod + Nom * Max(strike-b-a*rate,0) * accrualperiod
             * --> If a>0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg + Put(a*rate+b,strike)
             * --> If a<0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg + Nom * Max(strike-b+|a|*rate+,0) * accrualperiod =
             *          = VanillaFloatingLeg - Call(|a|*rate+b,strike)
             */

            // Positive gearing
            List <CashFlow> flooredLeg_p1 = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps0, floors,
                                                                   vars.volatility, gearing_p, spread_p);
            Swap floorLeg_p1 = new Swap(fixedLeg, flooredLeg_p1);

            floorLeg_p1.setPricingEngine(engine);
            Floor floor_p1 = new Floor(floatLeg_p, new InitializedList <double>(1, floorstrike));

            floor_p1.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla    = vanillaLeg_p.NPV();
            npvFlooredLeg = floorLeg_p1.NPV();
            npvFloor      = floor_p1.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla + npvFloor));
            if (error > tolerance)
            {
                QAssert.Fail("\nFloored Leg: gearing=" + gearing_p + ", "
                             + "spread= " + spread_p * 100 + "%, strike=" + floorstrike * 100 + "%, "
                             + "effective strike= " + (floorstrike - spread_p) / gearing_p * 100
                             + "%\n" +
                             "  Floored Floating Leg NPV: " + npvFlooredLeg
                             + "\n" +
                             "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor)
                             + "\n" +
                             "  Diff: " + error);
            }
            // Negative gearing
            List <CashFlow> flooredLeg_n = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps0, floors,
                                                                  vars.volatility, gearing_n, spread_n);
            Swap floorLeg_n = new Swap(fixedLeg, flooredLeg_n);

            floorLeg_n.setPricingEngine(engine);
            Cap cap_n = new Cap(floatLeg, new InitializedList <double>(1, (floorstrike - spread_n) / gearing_n));

            cap_n.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla    = vanillaLeg_n.NPV();
            npvFlooredLeg = floorLeg_n.NPV();
            npvCap        = cap_n.NPV();
            error         = Math.Abs(npvFlooredLeg - (npvVanilla - gearing_n * npvCap));
            if (error > tolerance)
            {
                QAssert.Fail("\nCapped Leg: gearing=" + gearing_n + ", " +
                             "spread= " + spread_n * 100 +
                             "%, strike=" + floorstrike * 100 + "%, " +
                             "effective strike= " + (floorstrike - spread_n) / gearing_n * 100 +
                             "%\n" +
                             "  Capped Floating Leg NPV: " + npvFlooredLeg + "\n" +
                             "  Floating Leg NPV - Cap NPV: " + (npvVanilla - gearing_n * npvCap) + "\n" +
                             "  Diff: " + error);
            }

            /* gearing = a and spread = b
             * COLLARED coupon - Decomposition of payoff
             * Payoff = Nom * Min(caprate,Max(a*rate+b,floorrate)) * accrualperiod
             * --> If a>0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg - Collar(a*rate+b, floorrate, caprate)
             * --> If a<0 (assuming positive effective strike):
             *    Payoff = VanillaFloatingLeg + Collar(|a|*rate+b, caprate, floorrate)
             */
            // Positive gearing
            List <CashFlow> collaredLeg_p = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors,
                                                                   vars.volatility, gearing_p, spread_p);
            Swap collarLeg_p1 = new Swap(fixedLeg, collaredLeg_p);

            collarLeg_p1.setPricingEngine(engine);
            Collar collar_p = new Collar(floatLeg_p, new InitializedList <double>(1, capstrike),
                                         new InitializedList <double>(1, floorstrike));

            collar_p.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla     = vanillaLeg_p.NPV();
            npvCollaredLeg = collarLeg_p1.NPV();
            npvCollar      = collar_p.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nCollared Leg: gearing=" + gearing_p + ", "
                             + "spread= " + spread_p * 100 + "%, strike="
                             + floorstrike * 100 + "% and " + capstrike * 100
                             + "%, "
                             + "effective strike=" + (floorstrike - spread_p) / gearing_p * 100
                             + "% and " + (capstrike - spread_p) / gearing_p * 100
                             + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg
                             + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar)
                             + "\n" +
                             "  Diff: " + error);
            }
            // Negative gearing
            List <CashFlow> collaredLeg_n = vars.makeCapFlooredLeg(vars.startDate, vars.length, caps, floors,
                                                                   vars.volatility, gearing_n, spread_n);
            Swap collarLeg_n1 = new Swap(fixedLeg, collaredLeg_n);

            collarLeg_n1.setPricingEngine(engine);
            Collar collar_n = new Collar(floatLeg, new InitializedList <double>(1, (floorstrike - spread_n) / gearing_n),
                                         new InitializedList <double>(1, (capstrike - spread_n) / gearing_n));

            collar_n.setPricingEngine(vars.makeEngine(vars.volatility));
            npvVanilla     = vanillaLeg_n.NPV();
            npvCollaredLeg = collarLeg_n1.NPV();
            npvCollar      = collar_n.NPV();
            error          = Math.Abs(npvCollaredLeg - (npvVanilla - gearing_n * npvCollar));
            if (error > tolerance)
            {
                QAssert.Fail("\nCollared Leg: gearing=" + gearing_n + ", "
                             + "spread= " + spread_n * 100 + "%, strike="
                             + floorstrike * 100 + "% and " + capstrike * 100
                             + "%, "
                             + "effective strike=" + (floorstrike - spread_n) / gearing_n * 100
                             + "% and " + (capstrike - spread_n) / gearing_n * 100
                             + "%\n" +
                             "  Collared Floating Leg NPV: " + npvCollaredLeg
                             + "\n" +
                             "  Floating Leg NPV - Collar NPV: " + (npvVanilla - gearing_n * npvCollar)
                             + "\n" +
                             "  Diff: " + error);
            }
        }
        public void testDecomposition()
        {
            // Testing collared coupon against its decomposition...

             CommonVars vars= new CommonVars();

             double tolerance = 1e-10;
             double npvVanilla,npvCappedLeg,npvFlooredLeg,npvCollaredLeg,npvCap,npvFloor,npvCollar;
             double error;
             double floorstrike = 0.05;
             double capstrike = 0.10;
             InitializedList<double> caps = new InitializedList<double>(vars.length,capstrike);
             List<double> caps0 = new List<double>();
             InitializedList<double> floors = new InitializedList<double>(vars.length,floorstrike);
             List<double> floors0 = new List<double>();
             double gearing_p = 0.5;
             double spread_p = 0.002;
             double gearing_n = -1.5;
             double spread_n = 0.12;
             // fixed leg with zero rate
             List<CashFlow> fixedLeg  = vars.makeFixedLeg(vars.startDate,vars.length);
             // floating leg with gearing=1 and spread=0
             List<CashFlow> floatLeg  = vars.makeYoYLeg(vars.startDate,vars.length);
             // floating leg with positive gearing (gearing_p) and spread<>0
             List<CashFlow> floatLeg_p = vars.makeYoYLeg(vars.startDate,vars.length,gearing_p,spread_p);
             // floating leg with negative gearing (gearing_n) and spread<>0
             List<CashFlow> floatLeg_n = vars.makeYoYLeg(vars.startDate,vars.length,gearing_n,spread_n);
             // Swap with null fixed leg and floating leg with gearing=1 and spread=0
             Swap vanillaLeg = new Swap(fixedLeg,floatLeg);
             // Swap with null fixed leg and floating leg with positive gearing and spread<>0
             Swap vanillaLeg_p = new Swap(fixedLeg,floatLeg_p);
             // Swap with null fixed leg and floating leg with negative gearing and spread<>0
             Swap vanillaLeg_n = new Swap(fixedLeg,floatLeg_n);

             IPricingEngine engine = new DiscountingSwapEngine(vars.nominalTS);

             vanillaLeg.setPricingEngine(engine);    // here use the autoset feature
             vanillaLeg_p.setPricingEngine(engine);
             vanillaLeg_n.setPricingEngine(engine);

             // CAPPED coupon - Decomposition of payoff
             // Payoff = Nom * Min(rate,strike) * accrualperiod =
             // = Nom * [rate + Min(0,strike-rate)] * accrualperiod =
             // = Nom * rate * accrualperiod - Nom * Max(rate-strike,0) * accrualperiod =
             // = VanillaFloatingLeg - Call
             //

             int whichPricer = 0;

             // Case gearing = 1 and spread = 0
             List<CashFlow> cappedLeg = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,
                              caps,floors0,vars.volatility);
             Swap capLeg = new Swap(fixedLeg,cappedLeg);
             capLeg.setPricingEngine(engine);
             YoYInflationCap cap = new YoYInflationCap(floatLeg, new List<double>(){capstrike});
             cap.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg.NPV();
             npvCappedLeg = capLeg.NPV();
             npvCap = cap.NPV();
             error = Math.Abs(npvCappedLeg - (npvVanilla-npvCap));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Capped Leg: gearing=1, spread=0%, strike=" + capstrike*100 +
                        "%\n" +
                        "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                        "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                        "  Diff: " + error );
             }

             // gearing = 1 and spread = 0
             // FLOORED coupon - Decomposition of payoff
             // Payoff = Nom * Max(rate,strike) * accrualperiod =
             // = Nom * [rate + Max(0,strike-rate)] * accrualperiod =
             // = Nom * rate * accrualperiod + Nom * Max(strike-rate,0) * accrualperiod =
             // = VanillaFloatingLeg + Put
             //

             List<CashFlow> flooredLeg = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,
                              caps0,floors,vars.volatility);
             Swap floorLeg = new Swap(fixedLeg,flooredLeg);
             floorLeg.setPricingEngine(engine);
             YoYInflationFloor floor= new YoYInflationFloor(floatLeg, new List<double>(){floorstrike});
             floor.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvFlooredLeg = floorLeg.NPV();
             npvFloor = floor.NPV();
             error = Math.Abs(npvFlooredLeg-(npvVanilla + npvFloor));
             if (error>tolerance)
             {
            Assert.Fail("YoY Floored Leg: gearing=1, spread=0%, strike=" + floorstrike *100 +
                        "%\n" +
                        "  Floored Floating Leg NPV: " + npvFlooredLeg + "\n" +
                        "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor) + "\n" +
                        "  Diff: " + error );
             }

             // gearing = 1 and spread = 0
             // COLLARED coupon - Decomposition of payoff
             // Payoff = Nom * Min(strikem,Max(rate,strikeM)) * accrualperiod =
             // = VanillaFloatingLeg - Collar
             //

             List<CashFlow> collaredLeg = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,
                              caps,floors,vars.volatility);
             Swap collarLeg = new Swap(fixedLeg,collaredLeg);
             collarLeg.setPricingEngine(engine);
             YoYInflationCollar collar = new YoYInflationCollar(floatLeg,
                     new List<double>(){capstrike},
                     new List<double>(){floorstrike});
             collar.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvCollaredLeg = collarLeg.NPV();
             npvCollar = collar.NPV();
             error = Math.Abs(npvCollaredLeg -(npvVanilla - npvCollar));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Collared Leg: gearing=1, spread=0%, strike=" +
                        floorstrike*100 + "% and " + capstrike*100 + "%\n" +
                        "  Collared Floating Leg NPV: " + npvCollaredLeg + "\n" +
                        "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar) + "\n" +
                        "  Diff: " + error );
             }

             // gearing = a and spread = b
             // CAPPED coupon - Decomposition of payoff
             // Payoff
             // = Nom * Min(a*rate+b,strike) * accrualperiod =
             // = Nom * [a*rate+b + Min(0,strike-a*rate-b)] * accrualperiod =
             // = Nom * a*rate+b * accrualperiod + Nom * Min(strike-b-a*rate,0) * accrualperiod
             // --> If a>0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg - Call(a*rate+b,strike)
             // --> If a<0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg + Nom * Min(strike-b+|a|*rate+,0) * accrualperiod =
             // = VanillaFloatingLeg + Put(|a|*rate+b,strike)
             //

             // Positive gearing
             List<CashFlow> cappedLeg_p = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps,floors0,
                              vars.volatility,gearing_p,spread_p);
             Swap capLeg_p = new Swap(fixedLeg,cappedLeg_p);
             capLeg_p.setPricingEngine(engine);
             YoYInflationCap cap_p = new YoYInflationCap(floatLeg_p,new List<double>(){capstrike});
             cap_p.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_p.NPV();
             npvCappedLeg = capLeg_p.NPV();
             npvCap = cap_p.NPV();
             error = Math.Abs(npvCappedLeg - (npvVanilla-npvCap));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Capped Leg: gearing=" + gearing_p + ", " +
                        "spread= " + spread_p *100 +
                        "%, strike=" + capstrike*100  + "%, " +
                        "effective strike= " + (capstrike-spread_p)/gearing_p*100 +
                        "%\n" +
                        "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                        "  Vanilla Leg NPV: " + npvVanilla + "\n" +
                        "  Cap NPV: " + npvCap + "\n" +
                        "  Floating Leg NPV - Cap NPV: " + (npvVanilla - npvCap) + "\n" +
                        "  Diff: " + error );
             }

             // Negative gearing
             List<CashFlow> cappedLeg_n = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps,floors0,
                              vars.volatility,gearing_n,spread_n);
             Swap capLeg_n = new Swap(fixedLeg,cappedLeg_n);
             capLeg_n.setPricingEngine(engine);
             YoYInflationFloor floor_n = new YoYInflationFloor(floatLeg,new List<double>(){(capstrike-spread_n)/gearing_n});
             floor_n.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_n.NPV();
             npvCappedLeg = capLeg_n.NPV();
             npvFloor = floor_n.NPV();
             error = Math.Abs(npvCappedLeg - (npvVanilla+ gearing_n*npvFloor));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Capped Leg: gearing=" + gearing_n + ", " +
                        "spread= " + spread_n *100 +
                        "%, strike=" + capstrike*100  + "%, " +
                        "effective strike= " + ((capstrike-spread_n)/gearing_n*100) +
                        "%\n" +
                        "  Capped Floating Leg NPV: " + npvCappedLeg + "\n" +
                        "  npv Vanilla: " + npvVanilla + "\n" +
                        "  npvFloor: " + npvFloor + "\n" +
                        "  Floating Leg NPV - Cap NPV: " + (npvVanilla + gearing_n*npvFloor) + "\n" +
                        "  Diff: " + error );
             }

             // gearing = a and spread = b
             // FLOORED coupon - Decomposition of payoff
             // Payoff
             // = Nom * Max(a*rate+b,strike) * accrualperiod =
             // = Nom * [a*rate+b + Max(0,strike-a*rate-b)] * accrualperiod =
             // = Nom * a*rate+b * accrualperiod + Nom * Max(strike-b-a*rate,0) * accrualperiod
             // --> If a>0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg + Put(a*rate+b,strike)
             // --> If a<0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg + Nom * Max(strike-b+|a|*rate+,0) * accrualperiod =
             // = VanillaFloatingLeg - Call(|a|*rate+b,strike)
             //

             // Positive gearing
             List<CashFlow> flooredLeg_p1 = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps0,floors,
                              vars.volatility,gearing_p,spread_p);
             Swap floorLeg_p1 = new Swap(fixedLeg,flooredLeg_p1);
             floorLeg_p1.setPricingEngine(engine);
             YoYInflationFloor floor_p1 = new YoYInflationFloor(floatLeg_p,new List<double>(){floorstrike});
             floor_p1.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_p.NPV();
             npvFlooredLeg = floorLeg_p1.NPV();
             npvFloor = floor_p1.NPV();
             error = Math.Abs(npvFlooredLeg - (npvVanilla+npvFloor));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Floored Leg: gearing=" + gearing_p + ", "
                        + "spread= " + spread_p *100+ "%, strike=" + floorstrike *100 + "%, "
                        + "effective strike= " + (floorstrike-spread_p)/gearing_p*100
                        + "%\n" +
                        "  Floored Floating Leg NPV: "    + npvFlooredLeg
                        + "\n" +
                        "  Floating Leg NPV + Floor NPV: " + (npvVanilla + npvFloor)
                        + "\n" +
                        "  Diff: " + error );
             }
             // Negative gearing
             List<CashFlow> flooredLeg_n = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps0,floors,
                              vars.volatility,gearing_n,spread_n);
             Swap floorLeg_n = new Swap(fixedLeg,flooredLeg_n);
             floorLeg_n.setPricingEngine(engine);
             YoYInflationCap cap_n = new YoYInflationCap(floatLeg,new List<double>(){(floorstrike-spread_n)/gearing_n});
             cap_n.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_n.NPV();
             npvFlooredLeg = floorLeg_n.NPV();
             npvCap = cap_n.NPV();
             error = Math.Abs(npvFlooredLeg - (npvVanilla - gearing_n*npvCap));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Capped Leg: gearing=" + gearing_n + ", " +
                        "spread= " + spread_n *100 +
                        "%, strike=" + floorstrike*100  + "%, " +
                        "effective strike= " + (floorstrike-spread_n)/gearing_n*100 +
                        "%\n" +
                        "  Capped Floating Leg NPV: " + npvFlooredLeg + "\n" +
                        "  Floating Leg NPV - Cap NPV: " + (npvVanilla - gearing_n*npvCap) + "\n" +
                        "  Diff: " + error );
             }
             // gearing = a and spread = b
             // COLLARED coupon - Decomposition of payoff
             // Payoff = Nom * Min(caprate,Max(a*rate+b,floorrate)) * accrualperiod
             // --> If a>0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg - Collar(a*rate+b, floorrate, caprate)
             // --> If a<0 (assuming positive effective strike):
             // Payoff = VanillaFloatingLeg + Collar(|a|*rate+b, caprate, floorrate)
             //
             // Positive gearing
             List<CashFlow> collaredLeg_p = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps,floors,
                              vars.volatility,gearing_p,spread_p);
             Swap collarLeg_p1 = new Swap(fixedLeg,collaredLeg_p);
             collarLeg_p1.setPricingEngine(engine);
             YoYInflationCollar collar_p = new YoYInflationCollar(floatLeg_p,
                        new List<double>(){capstrike},
                        new List<double>(){floorstrike});
             collar_p.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_p.NPV();
             npvCollaredLeg = collarLeg_p1.NPV();
             npvCollar = collar_p.NPV();
             error = Math.Abs(npvCollaredLeg - (npvVanilla - npvCollar));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Collared Leg: gearing=" + gearing_p + ", "
                        + "spread= " + spread_p*100 + "%, strike="
                        + floorstrike*100 + "% and " + capstrike*100
                        + "%, "
                        + "effective strike=" + (floorstrike-spread_p)/gearing_p*100
                        +  "% and " + (capstrike-spread_p)/gearing_p*100
                        + "%\n" +
                        "  Collared Floating Leg NPV: "    + npvCollaredLeg
                        + "\n" +
                        "  Floating Leg NPV - Collar NPV: " + (npvVanilla - npvCollar)
                        + "\n" +
                        "  Diff: " + error );
             }
             // Negative gearing
             List<CashFlow> collaredLeg_n = vars.makeYoYCapFlooredLeg(whichPricer,vars.startDate,vars.length,caps,floors,
                              vars.volatility,gearing_n,spread_n);
             Swap collarLeg_n1 = new Swap(fixedLeg,collaredLeg_n);
             collarLeg_n1.setPricingEngine(engine);
             YoYInflationCollar collar_n = new YoYInflationCollar(floatLeg,
                        new List<double>(){(floorstrike-spread_n)/gearing_n},
                        new List<double>(){(capstrike-spread_n)/gearing_n});
             collar_n.setPricingEngine(vars.makeEngine(vars.volatility,whichPricer));
             npvVanilla = vanillaLeg_n.NPV();
             npvCollaredLeg = collarLeg_n1.NPV();
             npvCollar = collar_n.NPV();
             error = Math.Abs(npvCollaredLeg - (npvVanilla - gearing_n*npvCollar));
             if (error>tolerance)
             {
            Assert.Fail("\nYoY Collared Leg: gearing=" + gearing_n + ", "
                        + "spread= " + spread_n*100 + "%, strike="
                        + floorstrike*100 + "% and " + capstrike*100
                        + "%, "
                        + "effective strike=" + (floorstrike-spread_n)/gearing_n*100
                        +  "% and " + (capstrike-spread_n)/gearing_n*100
                        + "%\n" +
                        "  Collared Floating Leg NPV: "    + npvCollaredLeg
                        + "\n" +
                        "  Floating Leg NPV - Collar NPV: " + (npvVanilla - gearing_n*npvCollar)
                        + "\n" +
                        "  Diff: " + error );
             }
             // remove circular refernce
             vars.hy.linkTo(new YoYInflationTermStructure());
        }