arg max data type

Question

Mats 2022-5-13

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评论： Steven Lord 2022-5-13

Take the following example

x = single(-(-2:2).^2);
[xm,ix]=max(x);
whos
  Name        Size            Bytes  Class     Attributes

  cmdout      1x33               66  char                
  ix          1x1                 8  double              
  x           1x5                20  single              
  xm          1x1                 4  single              

I think it strange that variable ix is of type double, and not integer, which would be the most logical alternative.

Anyway, I am using this kind of line for a code generation case, where double data type is banned.

Is there any way I can force max function to return an integer value for argmax (variable ix in code above)?

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Steven Lord 2022-5-13

I think it strange that variable ix is of type double, and not integer, which would be the most logical alternative.

I suspect that the two-output form of max predates the introduction of the integer data types to MATLAB.

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Answer 1

Matt J 2022-5-13

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在 MATLAB Online 中打开

No, but can't you just cast it to an integer type post-facto? E.g.,

ix=cast(ix,'uint32');

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Mats 2022-5-13

Hi. I did not even try this trick because I though that you cannot change the datatype of a variable when using code generation (which is generally true). However, becuase code generator is quite smart your suggestion works nicely.

Thank you Matt!

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