implementation of the proper orthogonal decomposition

input:

in commend line: N the number of snapshots M the number of modes

files: snapshots averaged field

data files should be in csv form

snapshots file named as [file_prefix].[file_number].[file_suffix], where [file_prefix] and [file_suffix] are specified in the script, [file_number] is a int in range(N)

averaged file name is in the line of data_ave = np.genfromtxt...

data to be employed for POD is specified in var_names

output: POD_coef.csv containing eigenvalues and first M mode eigenvectors POD_mode.csv

citation:

@inproceedings{Lu2018
author = {{Lu}, Zhen and {Elbaz}, Ayman M. and {Hernandez Perez}, Francisco E. and {Roberts}, William L. and {Im}, Hong G.},
        title = "{Large Eddy Simulations of the Vortex-Flame Interaction in a Turbulent Swirl Burner}",
    booktitle = {APS Division of Fluid Dynamics Meeting},
         year = "2018",
        month = "November",
          eid = {Q2.005}
}