How can I loop through a csv file that holds annual precipitation data and find out how many dry events there are?

I have a csv file with 365 days of precipitation data. I am interested in finding out the average time between rainy days. For example, here's an shortened example of the matrix: [0 0 .3 0 0 .5 .6 0 0 0] I want to count the the first occurrences of zeroes in the matrix. So this matrix would give me an answer of 3. Any help would be appreciated.

Answer 1

[dpb]

I presume you mean the first nonzero occurrences...

   mean(diff([0 find(r)]))  % average between rainy days including first from the file

If don't want to count the first, drop the prepended '0'

APPENDUM:

BTW, finding the transitions isn't actually "average between rainy days" it's between rain "events" as it doesn't include anything for successive days of rain. One can do that by converting to logical and then diff()

isr=r>0;  % logical "is rainy"
sum(diff([true isr])==-1)