How to fill in a matrix and compute its binary frequency?

Hello All,

I have thirty year of preciptation data in a vector form. I need to find the frequency of the dry and wet days and plot the frequency against days (1:365).

I am stuck as the following code place in the precipitation data however, i am not able to change it to a binary condition (Wet=1, dry=0). Can somebody help me out. I still have to count all the wet and dry days and make the frequency graph against the days (1:365).

Thanks

R=zeros(365,30); % Space for the data
P_data=P(:,4); % Preciptation data
n=length(P_data);
C=1;
for i=1:30;
    for j=1:365;
    R(j,i)=P_data(C);
    C=C+1;
    end

end
if R(j,i)>0; 
    R(j,i)=1; % imposing the wet conditon if the the value in the ith row and jth colum is larger then zero
else
    R(j,i)=0;
end

[Hydro]

I just updated my code which may give you a bit clear picture.

R=zeros(365,30); % Space for the data
P_data=P(:,4); % Preciptation data
n=length(P_data);
C=1;
W_days=0;
for i=1:30;
    for j=1:365;
    R(j,i)=P_data(C);
    C=C+1;
    end
if R(j,i)>0; 
    W_days=W_days+1;
end
prob(j)=W_days/30; % probability of wet days
end

plot(1:365,prob)

[Image Analyst]

Yes, but you still didn't attach P, or give code to read it in.

[Hydro]

the data

Answer 1

[dpb]

Leap years not accounted for?

If not, as the above would indicate, then

R=reshape(P_Data,365,[])>0;

[Hydro]

yes, the leap year is ignored for this analysis. any thought about the code would be appreciated. I still don't see what i wanted to see (Probability of precipitation occurrence against duration in days (1:365).

[dpb]

Not quite sure what you mean, precisely by Probability of precipitation occurrence against duration in days (1:365) but R above will be a logical array of T for rainy days arranged by year in columns. So, P(R|day) =

Prainbyday=sum(R,2)/size(R,2);

Clearly P(noRain) is the complement. Is that not what you're looking for?