# Count if a vector has at list one element greater than zero

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Enrico Gambini el 5 de Mzo. de 2021
Editada: Stephen23 el 6 de Mzo. de 2021
Hello everyone, I'm looking for a way to update a count if a vector has at least one element greater than zero.
I mean for example:
count=0;
v=rand(100,1);
%check if v has at least one element greater than zero, if yes
count=count+1;
Thank you
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Enrico Gambini el 5 de Mzo. de 2021
I think i got a part of the answer
if(any(v)) %returns true if any of the elements of v is nonzero
count=count+1;
end

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Jorg Woehl el 5 de Mzo. de 2021
Editada: Jorg Woehl el 6 de Mzo. de 2021
count = sum(v>0)
The expression v>0 creates a logical array of 1s and 0s, with a 1 for every element of v that is greater than zero. Summing all values in the logical array therefore gives the total number of elements greater than zero.
(By the way, the rand function only generates positive numbers between 0 and 1, so to create random numbers between -1 and 1, you would use 1-2*rand.)
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Jorg Woehl el 5 de Mzo. de 2021
I see - in this case, using the any function like you suggested would be the way to go. Test if at least one element of v is greater than zero and then increase the count variable accordingly:
if (any(v>0)) % returns true if at least one element of v is greater than zero
count=count+1;
end
Stephen23 el 6 de Mzo. de 2021
Editada: Stephen23 el 6 de Mzo. de 2021
Simpler:
count = count + any(v>0);

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