# How can I insert numbers 1-100 into the first column of a cell array?

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Brooke Yeager on 14 May 2021
Commented: Brooke Yeager on 14 May 2021
I know this sounds simple... maybe it's Friday and my brain is fried, so bare with me.
I have a cell array that is 100x8. I simply want the first column of this array to be numbers 1-100, such that the first row of the first column has a 1, the second row of the first column has a 2, the third row of the first column has a 3, and so on until the 100th row of the first column has 100. These numbers will correspond to the trial numbers.
I don't know why I can't figure this out.
the cyclist on 14 May 2021
Don't feel bad. Even after decades of use of MATLAB, I sometmes have to tinker around to remember the exact syntax for different operations using cell arrays. (Even with the solution I proposed, I feel in the back of my mind that there is a simpler way.)

the cyclist on 14 May 2021
Edited: the cyclist on 14 May 2021
Here is one way:
N = 100;
% Set up an empty cell array
C = cell(N,8);
% Fill the first column
C(:,1) = num2cell(1:N)
C = 100×8 cell array
{[ 1]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 2]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 3]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 4]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 5]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 6]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 7]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 8]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[ 9]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[10]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[11]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[12]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[13]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[14]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[15]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {[16]} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double} {0×0 double}
Brooke Yeager on 14 May 2021
This worked beautifully. Thank you for your help!!!

DGM on 14 May 2021
Someone can surely improve on this, but this is one way
C = cell(10,4) % i'm just going to use a smaller example array
C(:,1) = mat2cell((1:10).',ones(10,1),1)
gives
C =
10×4 cell array
{[ 1]} {0×0 double} {0×0 double} {0×0 double}
{[ 2]} {0×0 double} {0×0 double} {0×0 double}
{[ 3]} {0×0 double} {0×0 double} {0×0 double}
{[ 4]} {0×0 double} {0×0 double} {0×0 double}
{[ 5]} {0×0 double} {0×0 double} {0×0 double}
{[ 6]} {0×0 double} {0×0 double} {0×0 double}
{[ 7]} {0×0 double} {0×0 double} {0×0 double}
{[ 8]} {0×0 double} {0×0 double} {0×0 double}
{[ 9]} {0×0 double} {0×0 double} {0×0 double}
{[10]} {0×0 double} {0×0 double} {0×0 double}
Brooke Yeager on 14 May 2021