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davidshepherd7 / gist:4105231
Created Nov 18, 2012
1.31 Velocity Transformation
View gist:4105231
;; Just use the transformation from the example then pull out the velocity from the tuple.
(define (velocity-transform coordinate-transform)
(compose (lambda (tuple) (velocity tuple)) (F->C coordinate-transform)))
;; ;; Or explicitly using Gamma-bar this is:
;; (define (velocity-transform coordinate-transform)
;; (define (f-bar q-prime)
;; (define q (compose coordinate-transform (Gamma q-prime)))
;; (Gamma q))
;; (compose (lambda (x) (velocity x)) (Gamma-bar f-bar)))
davidshepherd7 / gist:4666285
Created Jan 29, 2013
example parallel parameter sweep for an oomph-lib driver
View gist:4666285
#!/usr/bin/env python
import subprocess as subp
from multiprocessing import Pool
import itertools
import sys
import numbers
import argparse
View Automatically run make on multiple cores
# Changes to defaults for "make"
# ============================================================
# How many cores do we have? Find out from /proc/cpuinfo (using regexp matching
# the start of info for a new processor).
NCORES=`grep --count '^processor[[:space:]]*:' /proc/cpuinfo`
# Apparently make runs fastest with one more job than there are cores.
NJOBS=$(($NCORES + 1))
View gist:5883871
/// \short Indexed output function to print a matrix to the stream outfile
/// as i,j,a(i,j) for a(i,j)!=0 only with a specified precision.
void sparse_indexed_output(std::ostream &outfile,
const unsigned &precision,
const bool& output_bottom_right_entry_regardless=false) const
// Note: we might have to specify "output_bottom_right_entry_regardless"
// as well (can't be a default). C++ can silently convert between
// unsigned and bool, so having a default set for
// output_bottom_right_entry_regardless would give the same function
View bdf2 adaptive
def emr_step(dt_n, y_n, dy_n, dt_nm1, y_nm1):
"""Take a single step of the explicit midpoint rule.
From G&S pg. 715 and Prinja's thesis pg.45.
dtr = dt_n / dt_nm1
y_np1 = (1 - dtr**2)*y_n + (1 + dtr)*dt_n*dy_n + (dtr**2)*(y_nm1)
return y_np1
def bdf2_dydt(ts, ys):
"""Get dy/dt at time ts[-1] (allowing for varying dt).
View adaptive unsteady newton.cpp
double Problem::
adaptive_unsteady_newton_solve(const double &dt_desired,
const double &epsilon,
const bool &shift_values)
//First, we need to backup the existing dofs, in case the timestep is
//Find total number of dofs on current processor
unsigned n_dof_local = dof_distribution_pt()->nrow_local();
View gist:d9b99d7762ca796d3501
(defun true1 () t)
(setq function-list (list #'true1))
(cons 'or function-list)
(eval (cons 'or function-list))
View gist:579fd585b891a81eec73
(defun dwim-entire-line (function)
(if (region-active-p)
(funcall function (region-beginning) (region-end))
;; else
(funcall function (point-at-bol) (point-at-beginning-of-next-line))))
(global-set-key (kbd "M-;") (lambda () (interactive)
(dwim-entire-line 'comment-or-uncomment-region)))
davidshepherd7 / gist:d9fe1ae929e3dde22c1d
Created Feb 10, 2015
Scaled block matrices in LaTeX
View gist:d9fe1ae929e3dde22c1d
\newcommand{\scalemath}[2]{\scalebox{#1}{\begin{math} {#2} \end{math}}}
\newcommand{\Aprime}{\scalemath{0.5}{\begin{matrix} \Amm & \Abound \\ \zm & -\Idm \end{matrix}}}
\newcommand{\Gprime}{\scalemath{0.5}{\begin{matrix} \zm & \zm \\ \zm & \bm \end{matrix}}}
\newcommand{\Qprime}{\scalemath{0.5}{\begin{matrix} \Qm \\ \zm \end{matrix}}}
Combining the above with the Jacobian matrix as derived in \cref{sec:llg-magn-coupl}, the complete Jacobian is
\Jm =
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