how find last row<>0

a=[3 4 5 0 3 4 0;4 5 0 0 0 0 0;0 0 0 0 0 0 0]

a =

3 4 5 0 3 4 0

4 5 0 0 0 0 0

0 0 0 0 0 0 0

i want to know the last rows wich element are ==0 ..solution idx=2!

i try this solution :find(sum(a,2)==0)-1 but it's no good because example :the sum 3 3 0 -3 -3 0 =0 but is not correct

[Dyuman Joshi]

Your phrasing is not clear (atleast to me).

a=[3 4 5 0 3 4 0;4 5 0 0 0 0 0;0 0 0 0 0 0 0]

a = 3×7

3 4 5 0 3 4 0 4 5 0 0 0 0 0 0 0 0 0 0 0 0

As you said, the output for the above array is 2, what is the logic behind that?

[piero]

a=flip(a)

for i=1:height(a)

if sum(a(i,:),2)>0 and sum(a(i+1,:),2)==0

memRow=i;

break;

end

end

t's similar this code but i don't to use loop and sum

I want to store the idx of the last row where there is at least one number <>0

Answer 1

[Matt J]

idx = find(~any(a,2),1,'last')-1