df1['01 h'] =df1['15min'].rolling(window=4,center=False).sum()
Note that the window=4 parameter means that it will accumulate 4 lines of 15 minute data, resulting in 1 hour precipitation. This parameter can be changed to whatever duration you want.
Python programming, with examples in hydraulic engineering and in hydrology.
df1['01 h'] =df1['15min'].rolling(window=4,center=False).sum()
import numpy as np # sample x and y data - example x = [7.76,10.11,11.89,14.81,15.49] y = [1.851,1.971,1.953,1.842,1.805] # the polyfit functions does the nth degree polynomial best fit on the data, # returning the polynomial coefficients n = 4 # 4th degree polynomial, you can change for whatever degree you want coefs = np.polyfit(x,y,n) # The poly1d function applies the polynomial function to our calculated coefficients polyf = np.poly1d(coefs) #if we want to apply our polynomial function to a range of x values xf = np.linspace(0,20) yf = polyf(xf)