Loop won't run past first loop, what am I doing wrong here?

I made a matrix with double values that the loop traverses through. Each loop, a variable is set to the row number, does the calculations, then inputs the value into the matrix on different new column. Everything inside the loop is correct, but for some reason, it just does the first row and then stops.

D = 1.056;
m = 0.040;
a=0

a = 0

for r=1+a
    A = (C{r,2}*0.5)^2*pi;
    Q = A*C{r,3};
    C{r,4} = Q;
    R = (D*C{r,3}*C{r,2})/m;
    C{r,5} = R;
    a=a+1;
end

Undefined variable 'C'.

[Chunru]

"for r=1+a" will loop only once. How many times do you want to loop? Try to post an excutable code segment (with all variables defined) for further assistance.

Answer 1

[Walter Roberson]

D = 1.056;
m = 0.040;
numrow = size(C,1);
for r = 1 : numrow
    C2 = C{r,2};
    C3 = C{r,3};
    A = (C2*0.5).^2*pi;
    Q = A .* C3;
    C{r,4} = Q;
    R = (D .* C3 .* C2)/m;
    C{r,5} = R;
end