#!/usr/bin/env python
# Wenchang Yang (wenchang@princeton.edu)
# Wed Jun 19 11:35:49 EDT 2024
#model bias of tau_y: model - obs
if __name__ == '__main__':
    import sys,os
    try:
        from misc.timer import Timer
        tt = Timer(f'[{os.getcwd()}] start ' + ' '.join(sys.argv))
    except:
        pass
import sys, os.path, os, glob, datetime
import xarray as xr, numpy as np, pandas as pd, matplotlib.pyplot as plt
#more imports
wython = '/tigress/wenchang/wython'
if wython not in sys.path: sys.path.append(wython); print('added to python path:', wython)
#from misc import get_kws_from_argv
import xesmf as xe
#
if __name__ == '__main__':
    try:
        tt.check('end import')
    except:
        pass
#
#start from here
model = 'CM2.1'
daname = 'tau_y'
#model
#ifile = f'FLOR.ocean.{daname}.mclim.1980-2016.e1.nc'
#ifile = f'FLOR.ocean.{daname}.mclim.1980-2016.e2.nc'
ifile = f'{model}.ocean.{daname}.mclim.1980-2016.e1.nc'
ofile = ifile.replace('ocean', 'ocean.bias')
if os.path.exists(ofile):
    print('[exists]:', ofile)
    sys.exit()
print('model data...')
da_model = xr.open_dataarray(ifile)
#obs
if daname == 'tau_x':
    ifile = 'era5.mean_eastward_turbulent_surface_stress.mclim.1980-2016.nc'
elif daname == 'tau_y':
    ifile = 'era5.mean_northward_turbulent_surface_stress.mclim.1980-2016.nc'
print('obs data...')
da_obs = xr.open_dataarray(ifile)
#regrid obs to model grid: see http://tigress-web.princeton.edu/~wenchang/pub/FLOR/test/wyregrid_atmos2ocean_tau_x.py
print('regrid to model grid...')
da_obs = da_obs.rename(longitude='lon', latitude='lat')
da_model = da_model.rename(xu_ocean='x', yu_ocean='y', geolon_c='lon', geolat_c='lat')
regridder = xe.Regridder(da_obs, da_model, 'bilinear')
da_regrid = regridder(da_obs)
#bias
print('bias...')
da_bias = da_model - da_regrid
da_bias.attrs = da_model.attrs
da_bias.attrs['long_name'] = f'{model} {daname} bias from ERA5'
#save
print('saving...')
da_bias.to_dataset(name=daname).to_netcdf(ofile)
print('[saved]:', ofile)


 
if __name__ == '__main__':
    #from wyconfig import * #my plot settings
    
    #savefig
    if 'savefig' in sys.argv or 's' in sys.argv:
        figname = __file__.replace('.py', f'.png')
        if 'overwritefig' in sys.argv or 'o' in sys.argv:
            wysavefig(figname, overwritefig=True)
        else:
            wysavefig(figname)
 
    try:
        tt.check(f'**Done**')
    except:
        pass
    print()
    if 'notshowfig' in sys.argv or 'n' in sys.argv:
        pass
    else:
        if 'plt' in globals(): plt.show()