MATLAB: Is the ‘sum’ function also outputting elements of the matrix

forgot semicolonmatrixoutput errorsum

I have a column vector that I am trying to take the sum of, but I want it to display only the sum. Every time I use the sum function it also spits out every element in the matrix, along with the sum, which I do not want it to do. This seemed like an easy fix, but I couldn't find anything online.

Best Answer

Did you write your OWN function called sum? Type this on the command line:

which sum -all

If you have written a function called sum, it will then show up. Delete it, as sum is a tremendously important tool in MATLAB. At the very least rename it, or move it off your search path.

The fact is, sum does NOT do as you describe, so the only way what you describe can happen is if you did exactly what I suggest.

Related Solutions

MATLAB: Inappropriate MATLAB warning when summing over columns

The warning is entirely accurate, if you want sum(X) to sum across the rows whether or not X is a vector (i.e. sum will always return a vector of size 1 x size(X, 2), then you should use

Y = sum(X, 1);

Your Y = sum(X', 2) is also the same as Y = sum(X, 1)' and is never equivalent to your Y=sum(X) (it's the conjugate transpose for non-vectors).

MATLAB: Problem with ‘sum’ command

You mean that the size of x is 10x10000, right? Not that x is the vector [10,10000], which is what you wrote.

There is no unique inverse to the sum() command. Think about it. If I tell you that 2+2 equals 4, there is no way to for you to undo that, and obtain 2 and 2 from 4. It could have been 1 and 3, or 0 and 4, or -1.1 and 5.1, etc.

Best Answer

Related Solutions

MATLAB: Inappropriate MATLAB warning when summing over columns

MATLAB: Problem with ‘sum’ command

Related Question