public void AssertSystemSolvable(List <Entity> equations, List <VariableEntity> vars, int rootCount = -1)
{
var sys = MathS.Equations(equations.ToArray());
var sol = sys.Solve(vars.ToArray());
Assert.IsTrue(sol.Shape[0] == rootCount || rootCount == -1, "Got " + sol.Shape[0] + " instead of " + rootCount);
for (int i = 0; i < sol.Shape[0]; i++)
{
foreach (var eq in equations)
{
var eqCopy = eq.DeepCopy();
Assert.AreEqual(sol.Shape[1], vars.Count, "Incorrect output of Solve");
for (int rootid = 0; rootid < sol.Shape[1]; rootid++)
{
eqCopy = eqCopy.Substitute(vars[rootid], sol[i, rootid]);
}
foreach (var uniqvar in MathS.Utils.GetUniqueVariables(eqCopy).FiniteSet())
{
eqCopy = eqCopy.Substitute(uniqvar.Name, 3);
}
var E = Number.Abs(eqCopy.Eval());
Assert.IsTrue(E.IsDefinite() && E < 0.0001,
"i: " + i + " eq: " + eq.ToString() + " E: " + E.ToString());
}
}
}
public void EqSysLatex()
{
var eq = MathS.Equations(
"x + 3",
"y + x + 5"
);
Assert.True(eq.Latexise().Length > 10);
}
internal static void AssertSystemSolvable(Entity[] equations, Entity.Variable[] vars, int rootCount, Integer?ToSub = null)
{
ToSub ??= 3;
var sol = MathS.Equations(equations).Solve(vars);
if (sol is null)
{
if (rootCount == 0)
{
return;
}
else
{
throw new Xunit.Sdk.XunitException($"{nameof(sol)} is null but {nameof(rootCount)} is {rootCount}");
}
}
if (rootCount != -1)
{
Assert.Equal(rootCount, sol.RowCount);
}
var substitutions = new Dictionary <Entity.Variable, Entity>();
for (int i = 0; i < sol.RowCount; i++)
{
foreach (var equation in equations)
{
var eqCopy = equation;
Assert.Equal(sol.ColumnCount, vars.Length);
substitutions.Clear();
for (int rootid = 0; rootid < sol.ColumnCount; rootid++)
{
substitutions.Add(vars[rootid], sol[i, rootid]);
}
eqCopy = eqCopy.Substitute(substitutions);
substitutions.Clear();
foreach (var uniqvar in eqCopy.Vars)
{
substitutions.Add(uniqvar, ToSub);
}
eqCopy = eqCopy.Substitute(substitutions);
var error = eqCopy.EvalNumerical().Abs();
Assert.True(error.IsFinite && error < 0.0001,
$"\n{nameof(equation)}: {equation.InnerSimplified.Stringize()}\n{nameof(i)}: {i}\n{nameof(error)}: {error.Stringize()}\n{nameof(sol)}: {sol.Stringize()}");
}
}
}
public static Tensor SolveSystem(this Entity[] equations, params VariableEntity[] vars) => MathS.Equations(equations).Solve(vars);