How do you check if an inputed number is an array/vector or just 1 value?

211 views (last 30 days)
Using function [a, b, c, d] = function_name(a,b,c,d)
I know that if it's an array, [] will be used in the input and the script will have to call a position of an array eg. y(1) or y(2)
If it's a discrete value it will just be y
Basically, instead of calling 1 value of a, i want to call 2 or more, etc
I don't know if that makes any sense, but it would be very helpful if someone could please just help me out.

Accepted Answer

Andrew Newell
Andrew Newell on 25 Apr 2014
You can use size to find the number of components in each variable, e.g.:
size(a)

More Answers (2)

Star Strider
Star Strider on 25 Apr 2014
Edited: Star Strider on 25 Apr 2014
If you want to check whether a particular argument is a scalar (single-value) or an array, use the size function:
[r,c] = size(x)
if (r > 1) | (c > 1)
xscalar = 0;
else
xscalar = 1;
end
Then you can treat it as a vector later in your code if xscalar = 0 or a scalar if xscalar = 1.

Rik
Rik on 12 Apr 2021
In my view using numel or isscalar (introduced somewhere between v6.5 and v7.1) would be a better solution.
xscalar = numel(x)~=1;
xscalar = isscalar(x);
That way you can avoid size. numel is useful if you have old releases to consider, but otherwise isscalar should work just fine.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!