/// <summary>
/// Get the user scale values associate with a particular point of a
/// particular curve.</summary>
/// <remarks>The main purpose of this method is to handle
/// stacked bars and lines, in which case the stacked values are returned rather
/// than the individual data values. However, this method works generically for any
/// curve type.
/// </remarks>
/// <param name="pane">The parent <see cref="GraphPane"/> object.</param>
/// <param name="curve">A <see cref="CurveItem"/> object of interest.</param>
/// <param name="iPt">The zero-based point index for the point of interest.</param>
/// <param name="baseVal">A <see cref="Double"/> value representing the value
/// for the independent axis.</param>
/// <param name="lowVal">A <see cref="Double"/> value representing the lower
/// value for the dependent axis.</param>
/// <param name="hiVal">A <see cref="Double"/> value representing the upper
/// value for the dependent axis.</param>
/// <returns>true if the data point is value, false for
/// <see cref="PointPairBase.Missing"/>, invalid, etc. data.</returns>
public static bool GetValues( GraphPane pane, CurveItem curve, int iPt,
out double baseVal, out double lowVal, out double hiVal )
{
hiVal = PointPair.Missing;
lowVal = PointPair.Missing;
baseVal = PointPair.Missing;
if ( curve == null || curve.Points.Count <= iPt || !curve.IsVisible )
return false;
Axis baseAxis = curve.BaseAxis( pane );
Axis valueAxis = curve.ValueAxis( pane );
if ( baseAxis is XAxis || baseAxis is X2Axis )
baseVal = curve.Points[iPt].X;
else
baseVal = curve.Points[iPt].Y;
// is it a stacked bar type?
if ( curve is BarItem && ( pane._barSettings.Type == BarType.Stack ||
pane._barSettings.Type == BarType.PercentStack ) )
{
double positiveStack = 0;
double negativeStack = 0;
double curVal;
// loop through all the curves, summing up the values to get a total (only
// for the current ordinal position iPt)
foreach ( CurveItem tmpCurve in pane.CurveList )
{
// Sum the value for the current curve only if it is a bar
if ( tmpCurve.IsBar && tmpCurve.IsVisible )
{
curVal = PointPair.Missing;
// For non-ordinal curves, find a matching base value (must match exactly)
if ( curve.IsOverrideOrdinal || !baseAxis._scale.IsAnyOrdinal )
{
IPointList points = tmpCurve.Points;
for ( int i=0; i<points.Count; i++ )
{
if ( ( baseAxis is XAxis || baseAxis is X2Axis ) && points[i].X == baseVal )
{
curVal = points[i].Y;
break;
}
else if ( !(baseAxis is XAxis || baseAxis is X2Axis) && points[i].Y == baseVal )
{
curVal = points[i].X;
break;
}
}
}
// otherwise, it's an ordinal type so use the value at the same ordinal position
else if ( iPt < tmpCurve.Points.Count )
{
// Get the value for the appropriate value axis
if ( baseAxis is XAxis || baseAxis is X2Axis )
curVal = tmpCurve.Points[iPt].Y;
else
curVal = tmpCurve.Points[iPt].X;
}
// If it's a missing value, skip it
if ( curVal == PointPair.Missing )
{
positiveStack = PointPair.Missing;
negativeStack = PointPair.Missing;
}
// the current curve is the target curve, save the summed values for later
if ( tmpCurve == curve )
{
// if the value is positive, use the positive stack
if ( curVal >= 0 )
{
lowVal = positiveStack;
hiVal = ( curVal == PointPair.Missing || positiveStack == PointPair.Missing ) ?
PointPair.Missing : positiveStack + curVal;
}
// otherwise, use the negative stack
else
{
hiVal = negativeStack;
lowVal = ( curVal == PointPair.Missing || negativeStack == PointPair.Missing ) ?
PointPair.Missing : negativeStack + curVal;
}
}
// Add all positive values to the positive stack, and negative values to the
// negative stack
if ( curVal >= 0 )
positiveStack = ( curVal == PointPair.Missing || positiveStack == PointPair.Missing ) ?
PointPair.Missing : positiveStack + curVal;
else
negativeStack = ( curVal == PointPair.Missing || negativeStack == PointPair.Missing ) ?
PointPair.Missing : negativeStack + curVal;
}
}
// if the curve is a PercentStack type, then calculate the percent for this bar
// based on the total height of the stack
if ( pane._barSettings.Type == BarType.PercentStack &&
hiVal != PointPair.Missing && lowVal != PointPair.Missing )
{
// Use the total magnitude of the positive plus negative bar stacks to determine
// the percentage value
positiveStack += Math.Abs( negativeStack );
// just to avoid dividing by zero...
if ( positiveStack != 0 )
{
// calculate the percentage values
lowVal = lowVal / positiveStack * 100.0;
hiVal = hiVal / positiveStack * 100.0;
}
else
{
lowVal = 0;
hiVal = 0;
}
}
if ( baseVal == PointPair.Missing || lowVal == PointPair.Missing ||
hiVal == PointPair.Missing )
return false;
else
return true;
}
// If the curve is a stacked line type, then sum up the values similar to the stacked bar type
else if ( curve is LineItem && pane.LineType == LineType.Stack )
{
double stack = 0;
double curVal;
// loop through all the curves, summing up the values to get a total (only
// for the current ordinal position iPt)
foreach ( CurveItem tmpCurve in pane.CurveList )
{
// make sure the curve is a Line type
if ( tmpCurve is LineItem && tmpCurve.IsVisible )
{
curVal = PointPair.Missing;
// For non-ordinal curves, find a matching base value (must match exactly)
if ( curve.IsOverrideOrdinal || !baseAxis._scale.IsAnyOrdinal )
{
IPointList points = tmpCurve.Points;
for ( int i = 0; i < points.Count; i++ )
{
if ( points[i].X == baseVal )
{
curVal = points[i].Y;
break;
}
}
}
// otherwise, it's an ordinal type so use the value at the same ordinal position
else if ( iPt < tmpCurve.Points.Count )
{
// For line types, the Y axis is always the value axis
curVal = tmpCurve.Points[iPt].Y;
}
// if the current value is missing, then the rest of the stack is missing
if ( curVal == PointPair.Missing )
stack = PointPair.Missing;
// if the current curve is the target curve, save the values
if ( tmpCurve == curve )
{
lowVal = stack;
// if ( curVal < 0 && stack == 0 )
// {
// stack = curVal;
// lowVal = curVal;
// hiVal = curVal;
// }
// else
hiVal = ( curVal == PointPair.Missing || stack == PointPair.Missing ) ?
PointPair.Missing : stack + curVal;
}
// sum all the curves to a single total. This includes both positive and
// negative values (unlike the bar stack type).
stack = ( curVal == PointPair.Missing || stack == PointPair.Missing ) ?
PointPair.Missing : stack + curVal;
}
}
if ( baseVal == PointPair.Missing || lowVal == PointPair.Missing ||
hiVal == PointPair.Missing )
return false;
else
return true;
}
// otherwise, the curve is not a stacked type (not a stacked bar or stacked line)
else
{
if ( ! (curve is HiLowBarItem) )
lowVal = 0;
else
lowVal = curve.Points[iPt].LowValue;
if ( baseAxis is XAxis || baseAxis is X2Axis )
hiVal = curve.Points[iPt].Y;
else
hiVal = curve.Points[iPt].X;
}
// Special Exception: Bars on log scales should always plot from the Min value upwards,
// since they can never be zero
if ( curve is BarItem && valueAxis._scale.IsLog && lowVal == 0 )
lowVal = valueAxis._scale._min;
if ( baseVal == PointPair.Missing || hiVal == PointPair.Missing ||
( lowVal == PointPair.Missing && ( curve is ErrorBarItem ||
curve is HiLowBarItem ) ) )
return false;
else
return true;
}
