Calculate frequency for each gridded

Hi. Is it possible that I want to,

Change the value of -1.00 untill -3.00 tu 1 and the rest as 0. Then, I want to know how much 1 in each grid, how can I calculate how much amount of 1?

Answer 1

[KSSV]

Let A be your matrix/ grid.

idx = A<-1 & A>-3 ; 
A(idx) = 1 ; 
A(~idx) = 0 ; 
nnz(A==1)
nnz(A==0)

[Nurul Ain Basirah Zakaria]

for i=1:5
for j=1:11
YES(:,i,j) = nnz((idx(:,i,j))==1);
NO(:,i,j) = nnz((idx(:,i,j))==0);
end
end

Then,

for i=1:5
for j=1:11
Freq(:,i,j)=YES(:,i,j)/420;
end
end

Lastly,

for i=1:5
for j=1:11
New_freq(:,i,j)=Freq(:,i,j)*100;
end
end

Is this okay?

I want to apply this formula for each grid:

Frequency=num of drought months/total month*100

As I want to plot it spatially.

Anyone can please help me?

[KSSV]

You need not to apply a loop. You can do all at once.

[Nurul Ain Basirah Zakaria]

But, is my way above is okay? Im not really good at looping yet

[KSSV]

yes = 0 ; no = 0 ; 
for i=1:5
    for j=1:11
        if idx(i,j)==1
            yes = yes+1 ; 
        elseif idx(i,j) == 0 
            no = no+1 ;
        end
    end
end

[Nurul Ain Basirah Zakaria]

sir, thank you very much. i will try to understand looping better