ivan-pi’s gists

ivan-pi / cbrt_libm_example.f90

Created July 10, 2020 08:46

Port of the libm cbrt function (https://svnweb.freebsd.org/base/head/lib/msun/src/s_cbrt.c?revision=342563&view=markup) from C to Fortran. This code has not been verified. Use at your own risk!

	! @(#)s_cbrt.c 5.1 93/09/24
	!
	! ====================================================
	! Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
	!
	! Developed at SunPro, a Sun Microsystems, Inc. business.
	! Permission to use, copy, modify, and distribute this
	! software is freely granted, provided that this notice
	! is preserved.
	! ====================================================

ivan-pi / ensemble_kf.f90

Created July 9, 2020 16:01

Ensemble Kalman filter from Evensen, G. (2003). The ensemble Kalman filter: Theoretical formulation and practical implementation. Ocean dynamics, 53(4), 343-367.

	module m_multa

	implicit none
	private

	public :: multa

	contains

	subroutine multa(A,X,ndims,nrens,iblkmax)

ivan-pi / cbrt_2.f90

Created June 28, 2020 12:09

Cube root code example 2

	module cbrt_mod2

	implicit none
	private

	public :: cbrt, sp

	interface cbrt
	module procedure cbrt_sp_sp
	module procedure cbrt_sp_csp

ivan-pi / cbrt_1.f90

Created June 28, 2020 12:07

Cube root code example 1

	module cbrt_mod1

	implicit none
	private

	public :: cbrt, sp, r

	interface cbrt
	module procedure cbrt_sp_sp
	module procedure cbrt_csp_csp

ivan-pi / continued_fractions.py

Created June 26, 2020 12:23

Basic functions for working with continued fractions. These are handy for approximating irrational numbers as ratios of integer. A Fortran solution is available at https://fortran-lang.discourse.group/t/implmentation-of-contnued-fraction/124/2

	import math
	from fractions import Fraction

	def continued_fraction(r,steps=10):

	cf = []

	for step in range(steps):
	i = math.floor(r)
	cf.append(i)

ivan-pi / fc_string_funcs.f90

Created June 10, 2020 11:57

See discussion at https://fortran-lang.discourse.group/t/best-practices-for-passing-c-strings/104/12

	subroutine C_F_STRPOINTER (STRARRAY, FSTRPTR, MAXLEN)
	use, intrinsic :: ISO_C_BINDING
	implicit none
	character, dimension(*), target, intent(in) :: STRARRAY
	character(:), pointer, intent(out) :: FSTRPTR
	integer, intent(in), optional :: MAXLEN

	integer :: curlen

	curlen = 0

ivan-pi / linspace.f90

Created December 19, 2019 18:54

Linspace in Fortran

	module linspace_mod
	use iso_fortran_env, only: dp => real64
	implicit none

	contains

	!>
	! Return evenly spaced numbers over a specified interval.
	!
	! Returns `num` evenly spaced samples, calculated over the interval `[start, stop]`.

ivan-pi / gist:5554aed5157c7c84c8ec04aef612977d

Created September 8, 2019 13:26

Biperiodic weight matrix example

	def biperiodic_weight_matrix(bbox,x, p, n, diffs,
	coeffs=None,
	phi=phs3,
	order=None,
	eps=1.0,
	stencils=None):
	'''
	Returns a weight matrix which maps a functions values at `p` to an
	approximation of that functions derivative at `x`. This is a convenience
	function which first creates stencils and then computes the RBF-FD weights

ivan-pi / ghiau.txt

Created April 18, 2019 14:31

Lid-driven cavity flow benchmark u-velocity values from Ghia, U. K. N. G., Ghia, K. N., & Shin, C. T. (1982), Journal of computational physics, 48(3), 387-411.

	# Ghia, U. K. N. G., Ghia, K. N., & Shin, C. T. (1982).
	# High-Re solutions for incompressible flow using the Navier-Stokes equations and a multigrid method.
	# Journal of computational physics, 48(3), 387-411.
	#
	# TABLE I
	# Results for $u$-velocity along Vertical Line through Geometric Center of Cavity
	#--------------------------------------------------------------------
	# Re
	# -------------------------------------------------------------
	# y 100 400 1000 3200 5000 7500 10000

ivan-pi / ghiav.txt

Last active August 13, 2024 13:49

Lid-driven cavity flow benchmark v-velocity values from Ghia, U. K. N. G., Ghia, K. N., & Shin, C. T. (1982), Journal of computational physics, 48(3), 387-411.

	# Ghia, U. K. N. G., Ghia, K. N., & Shin, C. T. (1982).
	# High-Re solutions for incompressible flow using the Navier-Stokes equations and a multigrid method.
	# Journal of computational physics, 48(3), 387-411.
	#
	# TABLE II
	# Results for $v$-Velocity along Horizontal Line through Geometric Center of Cavity
	# [Note: The velocity for Re = 400 and point (x,v) = (0.9063,-0.23827) is probably wrong]
	#--------------------------------------------------------------------
	# Re
	# -------------------------------------------------------------

Ivan Pribec ivan-pi