# --- introduction ---
The program reads trajectory files in ASCII format. It consists of get_diff.py & makeFile.sh.

# --- execute program ---
Command: ./get_diff -v [p] [-o mean] <TrajectoryFile>

expressions in brackets are options.

get_diff.py calls the bash script makeFile.sh. This step is nessecary to produce a output file in "LAGRANTO-format". The output file is <TrajectoryFile>_<[-v] and contains one additional column delta_<-v>.
Please make sure that the variable $LAGRANTO is set! This variable should point to the installation directory of LAGRANTO.


# --- Goal ---
The goal of the program is to trace the difference between a time interval of a chosen meteorological field. Please notice that the output file becomes shorter by one time step. One option can be used:

-o mean: Interpolate linear between every time step.

default: Take field of the time step closer to the starting point.