cumsum - cumulative sum

Calling Sequence

y=cumsum(x)

y=cumsum(x,'r') or y=cumsum(x,1)

y=cumsum(x,'c') or y=cumsum(x,2)

Parameters

• x : vector or matrix (real or complex)
• y : vector or matrix (real or complex)

Description

For a vector or a matrix x, y=cumsum(x) returns in y the cumulative sum of all the entries of x taken columnwise.

y=cumsum(x,'c') (or, equivalently, y=cumsum(x,2)) returns in y the cumulative sum of the columns of x: y(i,:)=cumsum(x(i,:))

y=cumsum(x,'r') (or, equivalently, y=cumsum(x,1)) returns in y the cumulative sum of the rows of x: y(:,i)=cumsum(x(:,i))

Examples

A=[1,2;3,4];
cumsum(A)
cumsum(A,'r')
cumsum(A,'c')
a=rand(3,4)+%i;
[m,n]=size(a);
w=zeros(a);
w(1,:)=a(1,:);
for k=2:m;w(k,:)=w(k-1,:)+a(k,:);end;w-cumsum(a,'r')
 

See Also

cumprod  sum