How can I multiply equation with number

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Eman Ahmed Elsayed
Eman Ahmed Elsayed 2011-5-31
I need to multiply a number by an equation
function [result] = SA_1(func,lamda)
%UNTITLED Summary of this function goes here
% Detailed explanation goes here
syms a;
a=lamda;
f=a*func;
result=f;
end
when I run I get the following error
??? Undefined function or method 'mtimes' for input arguments of type 'function_handle'.
Error in ==> SA_1 at 6
f=a*func;
I need any help

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采纳的回答

daniel.x16
daniel.x16 2011-5-31
put a dot (.) before the * sign.
i.e. f=a.*func
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Walter Roberson
Walter Roberson 2011-5-31
I doubt that. All that would do is change the error message from being about 'mtimes' to being about 'times'.

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更多回答（1 个）

Walter Roberson
Walter Roberson 2011-5-31
Your line "a=lambda" overwrites the "syms a" that was established on the line above. You probably do not need the "syms a".
What you probably want is
function [result] = SA_1(func,lamda)
result=@(x) lambda*func(x);
end
This will construct a new function handle that includes the multiplication.
Warning: you won't be able to differentiate the new function handle either. Only symbolic expressions can be differentiated by MATLAB, unless you write the differentiation yourself.

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