Function: math[cancel] - deletes real and complex numbers very close to zero from an expression
Calling Sequence:
cancel(expr);
cancel(expr, 'eps'=val);
Parameters:
expr - an algebraic expression
eps - the name 'eps'
val - a numeric value
Description:
The function searches an expression for real floats or complex floats. If the absolute value of the respective float is less than a given threshold, then this float is replaced with 0 in the expression. By default, the threshold is determined by the global math variable _MathEps which be default is set .1*10^(-7).
If a complex float is found in expr, cancel is applied to its real and imaginary part.
If you wish to choose another value for the threshold, pass the option 'eps' = <val>, where <val> is a numeric value (prefferably close to zero) or change the value of _MathEps .
This function is part of the math package, and so can be used only after performing the command with(math) or with(math, cancel).
Examples:
> with(math):
> p := x^4-12*x^3+25*x+116;
> fsolve(p, x, complex);
> newp := makepoly({%}, x);
> cancel(newp, eps=1e-5);
> roundf(%);
See Also:
math/cutzeros , math/roundf , math/slice .
Version History:
Version 1.0 - current as of February 26, 1998
Version 1.1 - current as of June 06, 1998
Version 1.1.1 - current as of April 16, 2000