Error using ones Size inputs must be integers.

Hi guys i have a problem with my code for error like on theme " Error using ones Size inputs must be integers. Error in m6 (line 6) K1 = ones(length(strings)/4,1);"

my data looks like (look on image) and my code (strings is my Data) :

    K1 = ones(length(strings)/4,1);
    K2 = ones(length(strings)/4,1);
    K3 = ones(length(strings)/4,1);
j=1;
for i = 2:length(strings) 
        WK11 = corrcoef((str2double(strings(2:i,2))), (str2double(strings(2:i,4))));
       if rem(i,4)==0
        K1(j,1) = WK11(2,1);
        j=j+1;
        end
end
j=1;
for i = 2:length(strings) 
        WK22 = corrcoef((str2double(strings(2:i,2))), (str2double(strings(2:i,3))));
        if rem(i,4)==0
        K2(j,1) = WK22(2,1);
        j=j+1;
        end
end;
j=1;
for i = 2:length(strings) 
        WK33 = corrcoef((str2double(strings(2:i,3))), (str2double(strings(2:i,4))));
       if rem(i,4)==0
        K3(j,1) = WK33(2,1);
        j=j+1;
        end
end;

I dont know how to solve this

[Guillaume]

@Themiya, I've deleted your answer because a) it is not formatted properly (use the {}Code buton), b) it does not even appear to answer the OP question, and c) it is a duplicate of your comment.

Answer 1

[Star Strider]

To force them to be integers, use fix, floor, ceil, or round.

Example —

K1 = ones(fix(length(strings)/4),1);

Be careful with the length, numel, and size functions, so you get the result you want.

[Guillaume]

Be careful with the length, numel, and size functions

Of the 3, length is the only one that could cause problem, so a simple rule is to never use it. numel or size with an explicit dimension is always safer.

[Star Strider]

I certainly agree that size with a specific dimension is best. For a vector, numel works, but for a matrix will not give the desired result, and length of course returns the greatest dimension. (I should have mentioned these details originally.)

[Adam]

numel 'works' for a matrix too depending what the 'desired result' is. I've used it numerous times to give me the total number of elements in the array. To be fair, I only started doing this though since Matlab suggested it as an improvement on my use of prod and size!

Answer 2

[Image Analyst]

strings is a cell array that does not have row (elements) that are an integer multipl of 4 so length(strings)/4 is not an integer. Rather than round that number I think it's best to track down the root cause of this, which is why strings is not a multiple of 4 when you think it always should be.

Answer 3

[Hector Molina]

I had a similiar problem,

as "ones" must to be integer, what I used as a solution, was the function "fix"

I can notice that you are dividing by 4 in your script, so try

ones(fix(length(strings)/4,1))

of course you will lose or gain information when apply "fix", however, it is posible your script (program) runs OK.