Data-treatment.md

-# Monthly runoff into annual
+- [ ] add explanation for harvest convertion to yield
+
+# Monthly runoff
+- convert monthly runoff to annual by summing :  
 ```
 if file_name == "mrunoff.nc":
         #convert number of months to years
-        nb_year = int(len(years)/12)
+        nb_year = int(len(years)/12) #years in months here
         tmp = np.zeros([nb_year,len(latitudes),len(longitudes)])
         #calculation of the sum over each year
         for k in range(0,nb_year,1):
             tmp[k] = np.sum(data[k*12:k*12+12],axis=0)
-        data = tmp
+        data = tmp  #[months,latitudes,longitudes]
 ```
-years,latitudes,longitudes = list from the file reading
-data = numpy array from the reading of the file [months,latitudes,longitudes]
-
-# harvest to yield
-`yield = np.multiply(np.multiply(harvest,0.02222222),1.14)`
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+# Harvest
+- Convert harvest to yield :  
+```
+yield = np.multiply(np.multiply(harvest,0.02222222),1.14)
+```
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