Returns the function value and its derivate at a given argument.
Spline.ValueAt ( arg As Double, [derivate As Double] ) As Double
The ValueAt method calculates the function value and its derivative at the given argument specified by the arg parameter. The arg parameter can be any value in tolerance range for a spline function (i.e. the B value should be positive for the BH-curve of soft magnet steel and so on).
The calculated value is returned as a function result. If the optional output parameter derivative is given, it takes the value of function derivative.