MATLAB: How i can sum the lines of a matrix

sum matrix

p.x

1 4 5 2 1 …

3 1 9 3 2 …

4 5 14 5 3

but with out knowing the number of lines or the number of rows

thanks

if a is a x-by-y matrix

b=sum(a) will give you a new b matrix which will be 1-by-y matrix which will have the summation of each column.

I am a little confused, do you mean like this:

Y = reshape(1:18,6,3)  % A manageable dimension.
Y_1 = sum(Y,2)

So in your case it would be

Y_1 = sum(Y,2).';

Or do you mean, more like this:

Y = 1:18
Y_1 = sum(reshape(Y,3,6))

So in your case it would be

Y_1 = sum(reshape(Y,320,467))

y = sum(MatrixA(MatrixA > 3))