feval - Evaluate MuPAD expressions

Syntax

Description

result = feval(symengine,F,x1,...,xn) evaluates F, which is either a MuPAD function name or a symbolic object, with arguments x1,...,xn, with result a symbolic object.

[result,status] = feval(symengine,F,x1,...,xn) returns the error status in status, and the error message in result if status is nonzero. If status is 0, result is a symbolic object. Otherwise, result is a string.

Examples

syms a b c x
p = a*x^2+b*x+c;
feval(symengine,'polylib::discrim', p, x)

ans =
b^2 - 4*a*c

Alternatively, the same calculation based on variables not defined in the MATLAB workspace is:

feval(symengine,'polylib::discrim', 'a*x^2 + b*x + c', 'x')

ans =
b^2 - 4*a*c

Do not use feval to access the MuPAD log function that represents the logarithm to an arbitrary base. The feval command evaluates log as the natural logarithm (the appropriate MuPAD function is ln):

feval(symengine,'log', 'E')

ans =
1

Evaluating log with two parameters results in the following error:

feval(symengine,'log', '10', '10')

Error using mupadengine.mupadengine>mupadengine.feval
MuPAD error: Error: expecting one argument [ln]

See Also

doc | evalin | read | symengine

How To

• Calling Built-In MuPAD Functions from the MATLAB Command Window

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