A map application that shows different tile schemes
Here is a map application that illustrates very well the different tile schemes used (TMS, QuadTree, Google Maps):
GDAL and OGR Python tips
Online documentation for GDAL/OGR Python is sparse. Here I show some recommended ways of learning more about GDAL/OGR in Python. Using Python interpreter You can learn about GDAL and OGR from inside the Python interpreter. Start python interpreter: $ python…
Pointers for GDAL and Python
GDAL is not very well documented, and a complete Python API documentation site is not something I’ve found. So here are the best tutorials I’ve found so far for GDAL + Python. GDAL Python samples on osgeo.org
Importing data from a CSV file into a Postgres table
Simple CSV file import You have a CSV file called “data.csv”. It has a header line, and is delimited using “;”. You want to import it into Postgres and a table called “your_table”: Create the database table. Set column-types so…
Low tech male/female voice detection system
I was drinking a bootle of water, while listening to a group of people having a debate. As the water level sunk, I noticed something. In the beginning the bottle would resonate/vibrate when the people with higher pitch voices talked.…
Really easy 3D graphics in LaTeX
Note: The word “easy” is relative to the other solutions I found for doing 3D graphics in LaTeX. The following template is adapted from the annotated 3d box example. % Template for drawing with tikz 3D package \documentclass[]{article} \usepackage{tikz} \usetikzlibrary{3d}…
Are IEEE papers getting less citations because of the paywall?
I’m in the process of doing research for my computer science ph.d. project. Like many others, I’m using Google Scholar to find interesting papers for my research. Some papers are available through ACM and some through IEEE.
How to load an ESRI Shapefile into a PostGIS DB
Assuming a shapefile called myshapefile.shp, a table mytable in schema xyz, in a PostGIS enabled database called mydb on localhost. The table is owned by user dbuser who has password “secret”. Using shp2pgsql shp2pgsql myshapefile -I xyz.mytable > statements.sql psql…
Howto make 3D graphics in LaTeX with tikz
tikZ and LaTeX PGF/TikZ is a tandem of languages for producing vector graphics from a geometric/algebraic description. You can use this language inside tex files, to programmatically draw nice 2D and 3D graphics. Another package which some people prefer for…
Installing Node.js on EC2 64-bit microinstance running Amazon Linux
Download sourcecode Choose the appropriate sourcecode version by going to wget # or use curl