The meaning of a length command

Question

What does length mean in this formant?

Walter Roberson · Accepted Answer

length is defined this way:
function calculated_length = length(Array)
   L = size(Array);
   if any(L == 0)
       calculated_length = 0;
   else
       calculated_length = max(L);
   end
end
That is, if any dimension of the input is 0, then the length of the array is defined as 0, and otherwise the length is defined as being the longest out of all of the dimensions (no matter which dimension it is.) 
To emphasize: length() does not refer specifically to the first dimension or the second dimension. Which can make it a problem. Suppose for example that you are passed in an array, w, that is typically a whole bunch of rows and two columns. Then you might get into the bad habit of using length(w) to query the number of rows, and that might work most of the time. But then there might be a time when w is passed in as one row with two columns, and because the number of columns, 2, is the maximum dimension, then length() would say 2. If you then tried to access row 2, you would have a problem.
You should only use length() when you are certain you are working on a vector and you do not care about the orientation of the vector. If you are not certain you are working with a vector, or you care about the orientation of the vector, then you should use size() instead of length()

The meaning of a length command

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The meaning of a length command

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