The coeff_files are listed in the following format:

The coefficients for surface polynomial fits are in the following order:
1st line - mean - droplets velocity (3rd order) 
2nd line - standard deviation - droplets velocity (3rd order)
3rd line - standard deviation - elevation angle distribution of droplets (3rd order) 
4th line - mean - elevation angle (2nd order)
5th line - shape factor - elevation angle (2nd order) 
6th line - mean - Number of droplets 
7th line - standard deviation - Number of droplets. 
8th line - mean - total number of drops. 
9th line - standard deviation - total number of drops. 


3rd order polynomial are listed in the following format 
(1 theta phi theta*phi theta^2 phi^2  theta1^2*(phi) phi^2*(theta) theta^3 phi^3)

2nd order polynomial  
(1 theta phi theta*phi theta^2 phi^2 )

See Figure 2 in the paper for explanation of theta and phi