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cumprod

cumprod — cumulative product

Calling sequence

y=cumprod(x)  
y=cumprod(x,'r') or y=cumprod(x,1)   
y=cumprod(x,'c') or y=cumprod(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=cumprod(x) returns in y the cumulative product of all the entries of x taken columnwise.

y=cumprod(x,'c') (or, equivalently, y=cumprod(x,2)) returns in y the cumulative elementwise product of the columns of x: y(i,:)=cumprod(x(i,:))

y=cumprod(x,'r') (or, equivalently, y=cumprod(x,2)) returns in y the cumulative elementwise product of the rows of x: y(:,i)=cumprod(x(:,i)).

Examples



A=[1,2;3,4];
cumprod(A)
cumprod(A,'r')
cumprod(A,'c')
rand('seed',0);
a=rand(3,4);
[m,n]=size(a);
w=zeros(a);
w(1,:)=a(1,:);
for k=2:m;w(k,:)=w(k-1,:).*a(k,:);end;w-cumprod(a,'r')

See also

cumsum, sum, prod
<< cothcumsum >>