Matlab cat() function: index exceeds matrix dimensions

Question

I am trying to concatenate an array of numbers from 1->(a-1) + (a+1)->n.

I was using the cat function

cat(2, 1:a-1, a+1:n)

but I am getting the error

Index exceeds matrix dimensions.

Unless I am completely mistaken, I am just trying to concatenate two matrices of numbers so I'm not quite sure why I'm getting this error.

I'm trying to accomplish this:

>> a = 3;
>> n = 10;
>> cat(2, 1:a-1, a+1:n)
ans = 
    [1,2,4,5,6,7,8,9,10]

Is this the wrong way to do it? Any idea why this error is coming up?

Answer 1

Do you have a variable called cat in your workspace?

>> cat(2, 2:3, 4:6)                   # this works fine
ans =
     2     3     4     5     6
>> cat = 1:3;                         # introduce the variable 'cat'
>> cat(2, 2:3, 4:6)                   # now it breaks
??? Index exceeds matrix dimensions.