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@fmder
fmder / elastic_transform.py
Last active August 22, 2021 14:54
Elastic transformation of an image in Python
import numpy
from scipy.ndimage.interpolation import map_coordinates
from scipy.ndimage.filters import gaussian_filter
def elastic_transform(image, alpha, sigma, random_state=None):
"""Elastic deformation of images as described in [Simard2003]_.
.. [Simard2003] Simard, Steinkraus and Platt, "Best Practices for
Convolutional Neural Networks applied to Visual Document Analysis", in
@dperelman
dperelman / blend.sh
Created March 8, 2015 10:40
Create simple slideshow video with blend effect between images.
#!/bin/sh
# Need at least an outfile and two images for this command to make sense.
if [ $# -lt 3 ]
then
echo USAGE: "$0" OUTFILE IMAGES...
echo Create simple slideshow video with blend effect between images.
echo
echo OUTFILE is video file to create, .mkv extension is recommended.
echo IMAGES is a sequence of images for the slideshow.
# Hello, and welcome to makefile basics.
#
# You will learn why `make` is so great, and why, despite its "weird" syntax,
# it is actually a highly expressive, efficient, and powerful way to build
# programs.
#
# Once you're done here, go to
# http://www.gnu.org/software/make/manual/make.html
# to learn SOOOO much more.
@kylebgorman
kylebgorman / autoloess.R
Last active November 28, 2022 16:06
autoloess.R: set the "span" (smoothing) hyperparameter for a LOESS curve so as to minimize AIC_c (includes a cute demonstration)
# autoloess.R: compute loess metaparameters automatically
# Kyle Gorman <gormanky@ohsu.edu>
aicc.loess <- function(fit) {
# compute AIC_C for a LOESS fit, from:
#
# Hurvich, C.M., Simonoff, J.S., and Tsai, C. L. 1998. Smoothing
# parameter selection in nonparametric regression using an improved
# Akaike Information Criterion. Journal of the Royal Statistical
# Society B 60: 271–293.
@jboner
jboner / latency.txt
Last active May 5, 2024 03:12
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD