User:Gringer

gringer is another of the numerous wikipedia consumers, also known as David Eccles (formerly David Hall).

I originally thought the name of the cat in the TV Show He-Man was called Gringer, and I thought that cat was an appropriate representation of my personality. Despite finding out that the cat's name was Cringer, I decided to stick to that "original" mis-heard name.

My academic interests are in human genetics (or more generally, biology), mathematical logic, and programming (as a hobby, rather than a career). This led me to work on a PhD in biomedical science, studying basic structures of genetic variation in the Māori population, which was accepted in the University library in December 2011. My thesis can be found here.

= Useful links =


 * Map Colors
 * WikiProject_Maps/Conventions : ongoing expansion, have fun ;)
 * Category:Chemical_images_that_should_be_in_SVG_format
 * WikiProject_Chemistry/Structure_drawing_workgroup/Mysid's_script
 * mapnik may provide a way to do more customisable world maps

= Map Drawing using Natural Earth Data =

Natural Earth Data (NED) &mdash; has a license that seems to fit wikimedia well (public domain). I have created a Perl script for converting shapefiles from Natural Earth Data into SVG files. Many useful features have been implemented: To come:
 * map-type based colours (with manual override)
 * shapes grouped by country (and by territory, if different)
 * mark countries as main/subject/interest
 * different colours for identified subject areas
 * centre map based on either specified lat/long point or country centre
 * supports multiple projections (anything supported by proj4)
 * lines of latitude and longitude
 * larger surrounding circle when point of interest is a single point
 * line simplification using Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm, with hashing to ensure already added points are always included)
 * bounding box / zooming for a particular region
 * ability to mark countries/regions as 'other political'|'outside'
 * style-sheet based colouring for easy customisation / changing of colours
 * load numerical data from a csv file to create a heatmap
 * proper clipping at SVG viewbox boundary &mdash; implemented for orthographic projections
 * zoom box clipping (e.g. using Sutherland–Hodgman algorithm) to remove more mindless Inkscape touch-ups. The Vatti_clipping_algorithm may be implemented if too many people complain about the boundary edges.
 * numbering regions and generating a list of region names &mdash; useful for regional maps, but NED resolution doesn't go down to regional levels for most countries
 * remove Geo::ShapeFile dependency

How To Create a World Map

 * 1) Download Admin 0 cultural boundaries and tiny country points from here.
 * 2) Save my Perl script in an appropriate place on your computer -- direct download here.
 * 3) Install the Geo::ShapeFile Perl library -- you can download a compiled version here (extract into the same directory), or install via cpanminus
 * 4) Set up Perl   to point to the Perl library directory (e.g.  )
 * 5) Run my script:
 * 6) View and clean up the generated map with Inkscape (if necessary):

OR


 * 1) Post a request for a map on the Map workshop page, and wait for the generated map.

Polynesia


= Other code =
 * My code for extracting primitive shapes from swfmill XML files to create SVG objects
 * this code seems to be able to extract fonts and some shapes, but not many other things

Colours and the Visible spectrum
I created an sRGB version of the Visible spectrum in August 2008, which got a bit of flack (most obviously from, see Talk:Visible spectrum) for not being a good representation of the true spectrum. This image has now been updated (August 2010) to use CIECAM02 brightness(J)/chroma(C)/hue(h) in order to better approximate the visible spectrum in sRGB. The description from the image page follows:

Spectral XYZ locus coordinates were found here. Every 10nm, the spectral locus point was used as the initial point in a search for a matching sRGB colour (assuming "Dim" viewing condition). The search was carried out by a binary search along a line in JCh space between the spectral point, and a point with 0.3 * brightness (J), 0 chroma (C), and the same hue (h) as the spectral point. The search finished when a point was found that was in sRGB space. The CAT02 matrix was modified as suggested in Brill(2008) to reduce yellow-blue problems by replacing the bottom row (0.0030, 0.0136, 0.9834) with (0,0,1). An iterative smoothing was carried out to eliminate the largest jumps in chroma (greater than 5% change). Code used to generate the colour gradient can be found here.

Colour is a tricky beast, and I don't think this will remain as my best representation of the spectrum, but I'm more convinced (after reading a number of research papers) that the CIECAM02 colour space is the most appropriate for this at the current time.



Other spectrum-related links

 * LuxCoreRender &mdash; a program that attempts to render spectra as faithfully as possible

Colour Wheel


= Images =