How do you use one vector to name another vector?

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Danny 2014-12-16

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评论： Star Strider 2014-12-18

If you have three vectors: vect1 = [1 2], vect2 = [4 5], and vect3 = {'name1';'name2'}, how do I name vect1 and vect2 using the contents of vect3, i.e., how do I obtain

name1 = [1 2]

name2 = [4 5].

I have found one solution where the function assignin is used but I was wondering if there may be a more streamlined/simpler solution?

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Image Analyst 2014-12-16

编辑：Image Analyst 2014-12-16

And if you don't know the names in advance so that you can hard code in the variable name, and you have to create the variable dynamically from strings, then how are you going to be able to refer to name1 and name2 later in your code? Like you said, there is a simpler way to do whatever it is you want to do, and that way does not involve doing what you asked for. I completely agree with Star Strider there. Just let us know what you really need to accomplish and, rather than suggest a bad method like this yourself, let us advise you how to get you there.

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Answer 1

Star Strider 2014-12-16

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在 MATLAB Online 中打开

What you want to do has to be near the top of everyone’s ‘Don’t Do This!’ list.

But if you must, this works:

vect1 = [1 2];
vect2 = [4 5];
vect3 = {'name1';'name2'};
for k1 = 1:length(vect3)
    eval([vect3{k1} sprintf(' = vect%-d',k1)]);
end
name1
name2

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Stephen23 2014-12-18

编辑：Stephen23 2014-12-18

Do not use eval. There is most definitely a better way of structuring your data:

http://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

http://blogs.mathworks.com/loren/2005/12/28/evading-eval/

http://blogs.mathworks.com/videos/2010/03/08/top-10-matlab-code-practices-that-make-me-cry/

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Star Strider 2014-12-18

The eval function has its uses. I Answered one Question a while ago where the OP had a number of 2D matrices output by a FORTRAN routine that gave sequential names to each matrix. The OP wanted to use a loop with eval to concatenate them to a single three-dimensional array.

Perhaps Danny has the reverse situation, in which he has to write 2D arrays to be read by another routine that won’t read MATLAB multidimensional arrays. That would be a perfectly legitimate reason to do what he wants to do.

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