Creating a sequential order vector from an unknown size vector

I'm creating a program that would take an unknown size vector from the user and create another vector by assigning a number in sequential order for each element in the vector.

For example, the user types in [2 8 4 6] I would like to create a vector that would read [1 2 3 4]. I can not use any for loops. I have tried using the length() and numel() option to start the count, but only get the actual size of the vector. Thank you for any help.

Answer 1

[Azzi Abdelmalek]

   a=[2 8 4 6]
out=1:numel(a)

[Tim Tuttle]

Thank you for your help. I was trying to use numel(a):1:end without any luck.

Answer 2

[Star Strider]

If you want it to automatically create both row and column vectors, depending on the dimension of the input vector, this works:

x1 = [2, 8, 4, 6];                                      % Row Vector
x2 = [2; 8; 4; 6];                                      % Column Vector
Vseq = @(x) cumsum(ones(size(x)));

v1 = Vseq(x1)                                           % Row Vector
v2 = Vseq(x2)                                           % Column Vector

v1 =

       1     2     3     4

v2 =

       1
       2
       3
       4