How to create a cumulative frequency array

2021 4 28
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更新时间：2021 4 30
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I am trying to create an array to compute the cumulative frequency of array Z, which are less than or equal to the time in minutes specified by the minutes array, V.
X1= sqrt(rand(1,1000));
X2= normrnd(20,5, 1,1000);
w= rand(1,1000);
X3 = (-log(1- w));
sz = [1 1000];
X4 = unifrnd(4,15, sz);
Z=X1+X2+X3+X4; %(note: Z is an array with 1000 values in one row)
V = linspace(1, 1000, 1000); %array V

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 采纳的回答

Jeff Miller
Jeff Miller 2021-4-28

1 个投票

This is inelegant, but it works:
cumFreq = zeros(size(V));
for i=1:numel(V)
cumFreq(i) = sum(Z<V(i));
end

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BigWaffle
BigWaffle 2021-4-29
so this computes the frequency per location in array??
Thanks!! i will try it out
BigWaffle
BigWaffle 2021-4-29
This does not seem to give me cumulative frequency per trials. like if there was 3 values in Y array that are less than V array then when it finds 3rd that fits logic it will give me 3 in new array. Freq+1+1+1 because logic has be fulfilled 3 times.
hope im explaining it well
Jeff Miller
Jeff Miller 2021-4-30
No, sorry, I guess I misunderstood the problem. Maybe a small numerical illustration would help make it clear what you are trying to count?
BigWaffle
BigWaffle 2021-4-30
so this is what i ended up with after many attempts
im trying to get frequency at each time step (V) for Z
V = linspace(1,1000,1000);
j = 1;
while sum(Y > V(j))>0
for j=j+1
freq(j) = sum(Z <= V(j));
end
end
BigWaffle
BigWaffle 2021-4-30
thanks to your guidance. it was working just needed a tweak

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