Is there any way to separate the terms of a product?
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Panagiotis Panagopoulos Papageorgiou
on 17 Feb 2019
Commented: Panagiotis Panagopoulos Papageorgiou
on 19 Feb 2019
Hello,
Let's say I have this function_handle: f = @(x) exp(x-2)*log(x)
Is it possible to assign each function that comprises this product to its own seperate variable i.e:
g = exp()
h = x-2
j = log()
k = x
Thank you!
2 Comments
John D'Errico
on 17 Feb 2019
Edited: John D'Errico
on 17 Feb 2019
Sure. Write your own expression parsing code.
f = @(x) exp(x-2)*log(x);
>> func2str(f)
ans =
'@(x)exp(x-2)*log(x)'
Accepted Answer
Walter Roberson
on 17 Feb 2019
If you have the Symbolic Toolbox, then
f = @(x) exp(x-2)*log(x)
syms x
temp = f(x);
op0 = feval(symengine, 'op', temp, 0)
rest = children(temp)
rest0 = arrayfun(@children, rest, 'uniform', 0)
and so on, taking op 0 and children each time. op 0 will be things like _mult and _plus for * and + (and subtraction -- subtraction is _plus of negative of the value).
With a little work, you could create a routine that broke expressions down into nested cell arrays or into nested struct.
This is not a nice interface, but it is all that is availabe in the symbolic toolbox in any released version.
3 Comments
Walter Roberson
on 18 Feb 2019
I attached code that produces a nested cell parse tree. You could modify it.
The current last line has {op0} which will produce the token such as exp . You would want to look at length(rest) and use that many nominal variables similar to the representative_vars that I introduce near the beginning of the code to convert simple @functionname into functionname(x, y, z, ...) expressions.
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