Passing String from Cell Array to Matrix

The following code is producing the errors:

Matrix index is out of range for deletion.

names{s}(vec_missing(q)-q+1,:)=[];

The strings in the array are the names of four matrices (as an example). The vector vec_missing contains the integer values of the rows in the matrices I want to delete.

However, I have no idea why passing the string from the cell array is not working. I've tried searching the forum, but any help is appreciated:

      names = {'Mary','Mark','Luke','John'};

      for q=1:length(vec_missing);

      for s=1:numel(names)

      names{s}(vec_missing(q)-q+1,:)=[];

      end

      end

[dpb]

HINT: What happens to length() of the array when something is deleted from it? It's a very common newbie mistake -- working from the front to the end when deleting and thereby changing the location...

[David Young]

I suspect the problem is that you are trying to use the strings in names as if they were variable names. But you can't do this without calling the eval function. I'm not offering that as an answer, though, because it would be a bad solution. Better would be to store your arrays in a cell array, rather than their names.

[Charlie]

DPB - If you look carefully, you can see that I have corrected for this by subtracting the value of the loop iteration (q) (and actually has nothing to do with the question which I asked, anyway).

David Young - Thank you for your very useful advice.

[dpb]

I wasn't dreaming you really intended that the names were intended to be the names of the arrays you intended the loop to act on. I'm w/ David Y; this is a bad idea and as the FAQ says, "don't do that!!!"

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Answer 1

[Gitesh Nandre]

I agree with David Young and dpb. You are using strings from 'names' cell array as names of variables for matrices. This is not possible without using 'eval' function. However, it is not recommended. As David suggested, here is a solution which makes use of cell array for storing matrices.

Mary = magic(3); %Creating sample matrices of dimension 3x3
Mark = magic(3);
Luke = magic(3);
John = magic(3);

vec_missing = [1 3]; % Need to delete fist and third row from each matrix

names = {Mary Mark Luke John}; %Storing above matrices in cell array

for i = 1:numel(names)
    names{i}(vec_missing,:) = [];
end