Does different MATLAB versions handle array arithmetic differently ?

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Ronny Landsverk
Ronny Landsverk am 8 Jun. 2018
Kommentiert: James Tursa am 8 Jun. 2018
In a previous project I did something like
x = randn(N,3); % N > 1
x = x - [x,y,z]; % remove "bias", x,y,z are scalars
Im am pretty sure that this was allowed in a previous version of MATLAB. Am I wrong ?

Antworten (1)

John D'Errico
John D'Errico am 8 Jun. 2018
In R2016 (not sure if it was a or b. I think b, but not really relevant, so will not check.) they introduced the capability to expand singleton dimensions for operations like this.
So now things like this work:
M = magic(3)
M =
8 1 6
3 5 7
4 9 2
M - mean(M)
ans =
3 -4 1
-2 0 2
-1 4 -3
Which is as you describe. Prior to the change, you needed to use bsxfun to do that, and before bsxfun existed, you had to expand the vector yourself, using a tool like repmat.

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