jswhit’s gists

jswhit / test_localsolver_multiscale.py

Last active April 24, 2023 15:05

test multiscale LETKF solver

	"""non-cycled 1d test of LETKF with multiscale localization"""
	import numpy as np
	from scipy.linalg import eigh, lapack, solve
	from scipy.fft import rfft, irfft, rfftfreq
	from argparse import ArgumentParser

	# set random seed for reproducibility
	#np.random.seed(42)

	def syminv(C):

jswhit / test_enkfsolvers.py

Last active January 27, 2021 19:55

EnKF solver test (local vs global solution, with B or R localization)

	"""non-cycled 2d test of LETKF solver with B or R localization"""
	import numpy as np
	from scipy.linalg import eigh, inv, pinvh
	from scipy.special import gamma, kv
	from argparse import ArgumentParser

	# function definitions.

	def cartdist(x1,y1,x2,y2,xmax,ymax):
	"""cartesian distance on doubly periodic plane"""

jswhit / Spharmt.py

Last active August 28, 2020 22:51

interface to shtns spectral transform lib

	import shtns
	import numpy as np
	class Spharmt(object):
	"""
	wrapper class for commonly used spectral transform operations in
	atmospheric models.
	"""
	def __init__(self,nlons,nlats,ntrunc,rsphere=6.3712e6,gridtype='gaussian'):
	self._shtns = shtns.sht(ntrunc, ntrunc, 1, \
	norm=shtns.sht_orthonormal+shtns.SHT_NO_CS_PHASE)

jswhit / parallel_nn_sphere.py

Last active January 8, 2019 17:34

MPI parallel nearest neighbor search on a sphere

	from __future__ import print_function # Python 3 compatible print function
	"""find nearest neighbors for points on a sphere when locations to be compared
	are distributed across MPI tasks"""
	# to run: mpirun -np 4 python parallel_nn_sphere.py
	# requires mpi4py ('conda install mpi4py' in anaconda python)
	from mpi4py import MPI
	import numpy as np
	import sys

	# generate lat,lon values for random points on the surface of a unit sphere

jswhit / writing_netCDF.ipynb

Created October 18, 2014 17:34

writing netcdf ipython notebook

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jswhit / reading_netCDF.ipynb

Created October 18, 2014 17:32

reading netcdf ipython notebook

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jswhit / reading_netCDF.slides.html

Created October 18, 2014 16:40

reading netcdf ipython notebook slides


	<!DOCTYPE html>
	<html>
	<head>

	<meta charset="utf-8" />
	<meta http-equiv="X-UA-Compatible" content="chrome=1" />

	<meta name="apple-mobile-web-app-capable" content="yes" />
	<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />

jswhit / basemap_pygrib.ipynb

Last active August 30, 2023 17:22

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jswhit / basemap_netcdf4-python.ipynb

Last active January 13, 2019 17:44

ipython notebook: matplotlib + netcdf4-python

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jswhit / swm_test.py

Created October 6, 2012 15:58

shallow water model python test for shtns

	import shtns
	import numpy as np

	class Spharmt(object):
	"""
	wrapper class for commonly used spectral transform operations in
	atmospheric models. Provides an interface to shtns compatible
	with pyspharm (pyspharm.googlecode.com).
	"""
	def __init__(self,nlons,nlats,ntrunc,rsphere,gridtype='gaussian'):

Jeff Whitaker jswhit