The following functions allow you to determine the size of a variable or
expression. These functions are defined for all objects. They return
−1 when the operation doesn't make sense. For example, Octave's
data structure type doesn't have rows or columns, so the
columns functions return −1 for structure arguments.
Return the `length' of the object a. For matrix objects, the length is the number of rows or columns, whichever is greater (this odd definition is used for compatibility with Matlab).
Return the number rows and columns of a.
With one input argument and one output argument, the result is returned in a row vector. If there are multiple output arguments, the number of rows is assigned to the first, and the number of columns to the second, etc. For example,size ([1, 2; 3, 4; 5, 6]) => [ 3, 2 ] [nr, nc] = size ([1, 2; 3, 4; 5, 6]) => nr = 3 => nc = 2
If given a second argument,
sizewill return the size of the corresponding dimension. For examplesize ([1, 2; 3, 4; 5, 6], 2) => 2
returns the number of columns in the given matrix.