Addtion with 2x1 Vector and 2x3 Matrix

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EM
EM 2017-3-21
评论： EM 2017-3-22
Hi,
In the 2017a documentation, I find that you can "Create an array, A, and add a column vector to it. The vector is treated as though it is a matrix of the same size as A, so that each element in the vector is added to a row in A."
https://www.mathworks.com/help/matlab/ref/plus.html
I am using an older release of Matlab (2015a) and this operation does not work for me. I get the following error:
Error using + Matrix dimensions must agree.
Can anyone tell me how to perform this operation on an older release, and exactly which release was this new functionality available?
Thanks

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Jan
Jan 2017-3-21
编辑：Jan 2017-3-21
The new method was introduced in R2016b. See e.g. Loren: arithmetic-expanding. Use bsxfun for older Matlab versions:
A = rand(2, 3)
b = rand(2, 1)
R1 = bsxfun(@plus, A, b) % Matlab < 2016b
R2 = A + b % Matlab >= 2016b
bsxfun was introduced in 2007a. Before the array way expaned by repmat or ones:
R3 = A + b(:, ones(1, 3))
R4 = A + repmat(b, [1, 3])
The ones-method was processed efficiently by Matlab's JIT acceleration: The timings looked like Matlab does not waste time with creating the expanded array explicitely, but the addition was performed directly. But this is an assumption only: The JIT was never documented exactly.
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Steven Lord
Steven Lord 2017-3-21
In the section for release R2016b it's the first item in the Mathematics subsection. It's called implicit expansion.
EM
EM 2017-3-22
Thanks for all the help guys! Much appreciated!

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