# How to calculate the average without taking zeros values?

142 views (last 30 days)
afrya on 12 Dec 2013
Commented: Dongpeng Lin on 3 Dec 2019
Hi, I have a large data list which has this form:
Y=
1 2 4 5 6 7 0 0 0 8 9 0 0 0 0... AVerage1=5.25
2 3 4 5 6 7 0 0 0 8 0 0 0 9 0... Average2=5.5
3 4 5 6 7 8 9 0 0 0 0 0 0 0 0... Average3=6
.
.
.
I would like to calculate the average of each row wihout taking zeros values.

Andrei Bobrov on 13 Dec 2013
[ii,~,v] = find(Y);
out = accumarray(ii,v,[],@mean);
Guanting SU on 10 Mar 2019
This worked out really well!
Dongpeng Lin on 3 Dec 2019
Thank God

Jos (10584) on 13 Dec 2013
Edited: Jos (10584) on 13 Dec 2013
No need of a loop:
A = [1 2 3 ; 10 0 30 ; 9 0 0]
rowMean = sum(A,2) ./ sum(A~=0,2)
Note that zeros do not contribute to sum(A) …
Jan on 26 Apr 2018
Edited: Jan on 10 Mar 2019
+1: Easy and efficient.
Excellent!!!! Thanks

Simon on 12 Dec 2013
Hi!
for n = 1:size(Y, 1)
Average(n) = mean(Y(n, (Y(n, :) ~= 0)));
end
afrya on 13 Dec 2013

Mech Princess on 5 Mar 2019
mean(nonzeros(X))
Y=[1 2 4 5 6 7 0 0 0 8 9 0 0 0 0; ...
2 3 4 5 6 7 0 0 0 8 0 0 0 9 0;...
3 4 5 6 7 8 9 0 0 0 0 0 0 0 0];
for i=1:3
mean(nonzeros(Y(i,:)))
end