November 2024 M T W T F S S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Category Archives: Data
Debian online upgrade from i386 to amd64 architecture
Jan 2011: Tried this recently on a P4 machine. After a library relink, the machine stopped working… I had to give in and do a fresh amd64 reinstall. No idea why it didn’t work now. Having a relatively freshly installed … Continue reading
Posted in linux
Comments Off on Debian online upgrade from i386 to amd64 architecture
svg and html
Using an uptodate browser (or a java script library, such as svgweb) it is fairly easy to integrate a svg file into a html page and to handle the svg-file from html, for a primer, see e.g. alistapart.com. Basically, when … Continue reading
SQL – setting and resetting in one query
A colleague has a web application where a number of flags can be set or reset using checkboxses. These flags corresponds to rows in a table. When they have been altered, those who are set are returned from the browser, … Continue reading
Posted in sql
Comments Off on SQL – setting and resetting in one query
Making stripcharts using svg and javascript
April 2013: I have made a new project based on this, although for static plotting. I needed to present data in a webapplication using strip chart. From earlier experiences on data presentation, I knew that making bit mapped graphics to … Continue reading
PHP Matrix multiplication
Needing to do some matrix multiplication in php, I found some code that looked quite promising, but it had a couple of problems: In addition to the matrixes, it needed the max dimentions of the matrixes as arguments and it … Continue reading
Posted in php
Comments Off on PHP Matrix multiplication
Concatenating a utf8 char field and a datetime field in mysql
In a database of mine (using mysql 5), I needed to make a ‘fake name’ – concatenating the real name and a datetime, so I did a concat(name, ‘(‘,thetime,’)’) in the sql and got just what I expected TheName (2011.02.02 … Continue reading
Posted in sql
Comments Off on Concatenating a utf8 char field and a datetime field in mysql
Legend in kml-files
How to trick with css to get different colored item markers and black text in a ul Continue reading
Making a kml-file showing measured values
I have a lot of measurement data stored in a database and am constantly looking for good ways of visualizing my data sets. A simple example of a way of creating a kml point-cover can be found here:kml_points.php A kml … Continue reading
Generation of dynamic kml files
I have a number of geographical datasets in a database that I would like to visualize as kml-files. For google earth to behave correctly, it is not just enough that the “Content-Type” is correctly set. The file must end with … Continue reading
Convert vmap0 layers into shapefiles
The vmap0 dataset is a slightly dated, but anyhow often usable dataset of maps of all of the world in scale 1:1 000 000. It can be downloaded at e.g. mapability.com. The problem shows up as soon as one tries to use … Continue reading
You must be logged in to post a comment.