Assign Values to Each Element of Symbolic Array

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Hello,

I have an array of symbolic values and I want to assign values to each symbolic variable in the array?

For example if I have

syms x1 x2 x3 x4 x5
X = [x1 ; x2 ; x3 ; x4 ; x5];
Values = [1 ; 2 ; 3 ; 4 ; 5];

I want to assign each symbolic element of X equal to the corresponding number in Values (in this case x1 = 1, x2 = 2, etc). Is there a way to do this?

X = deal(values) does NOT work because it assigns X = [1 ; 2 ; 3 ; 4 ; 5] rather than x1 = 1, x2 = 2, x3 = 3, x4 = 4, x5 = 5 like I want

Thank you,

Kevin

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Answer 1

Deepak Ramaswamy 2014-5-14

编辑：Deepak Ramaswamy 2014-5-14

在 MATLAB Online 中打开

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I really don't like this solution at all but does this work for you?:

syms x1 x2 x3 x4 x5
X = [x1 x2 x3 x4 x5].';
values = [1 2 3 4 5].';
for k = 1:numel(X)
    eval(sprintf('%s=values(%d)',char(X(k)),k));
end

This creates x1 x2 etc in the MATLAB workspace

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Kevin Bachovchin 2014-5-14

That does work. However, if I want to substitute in numerical values in expressions that contain x1, x2, etc, I need to use the "subs" command.

NewExpr = subs(OldExpr, X, values)

The "subs" command is pretty inefficient from what I see though. I think I'm better off creating a function handle from the symbolic expression using the "matlabFunction" command.

Deepak Ramaswamy 2014-5-14

I agree using matlabFunction() whenever the symbolic expression is "set" (i.e. there is no need for further symbolic operations) will provide better performance.

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Assign Values to Each Element of Symbolic Array

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