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Function Changem or substitute values of a matrix

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MSP on 18 May 2018
Commented: MSP on 19 May 2018
I am trying to use the function "changem" to substitute values from a matrix..(reference page: I am using matlab 2017a but when I use the function, matlab says that the function is undefined.. I cannot find results when I search for it in the DOC.
Does this function still exists? When no, is there a equivalent function? Or does someone knows a possibility to change values of a matrix (is a little bit complex because I want to change the values of the matrix by an equivalent value of a vector).
Thanks in advance, MP

Accepted Answer

Guillaume on 18 May 2018
Edited: Guillaume on 18 May 2018
As per sloppydisk's answer, changem requires the mapping toolbox, so clearly you don't have that installed.
I don't have the mapping toolbox either, but reading the function documentation, it seems trivial to implement:
function mapout = my_changem(mapout, newcode, oldcode)
assert(numel(newcode) == numel(oldcode), 'newcode and oldecode must have the same number of elements');
[toreplace, bywhat] = ismember(mapout, oldcode);
mapout(toreplace) = newcode(bywhat(toreplace));
  1 Comment
MSP on 19 May 2018
Thanks, works perfectly. After playing around sometime I did to manage it using 2 for loops and using if loops to check the constrains. But thanks again for the answer!

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More Answers (1)

sloppydisk on 18 May 2018
changem is part of the Mapping toolbox, type
to see which toolboxes you have installed.

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