Template talk:Location map Scotland

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[edit] Scotland location map

I am opening this discussion here because conducting two conversations with two different people over two different talk pages was too difficult. The situation is as follows:

[edit] Background

  • The original Scotland location map (map A) does not and will not work. It will not work because (from the description given to me) it is unprojected raw geodesic WGS84 data and not an equidistant cylindrical projection, nor a linear distortion of one.
  • I have produced four maps that will work. They are map B, map C, map D and map E.
    • map B is map A cut up manually in Microsoft Paint and repositioned to fit an equidistant cylindrical projection.
    • map C is a equidistant cylindrical projection map created by NASA from a mosaic of satellite photos.
    • map D is map B stretched vertically by 150% (the same solution that Russia uses on its location maps).
    • map E is map C stretched vertically by 150%.
  • Those maps will work: see here for an analysis.
  • Yesterday, I put map D into production via this diff. I tested it against Aberdeen, Inverness, Stornoway, Lockerbie, Lerwick, Glasgow, Brodick and Kirkwall and it worked perfectly. Job done.
  • Unfortunately, yesterday the Great Commons Cache problem happened (see here for the discussion under "Image problems"), and many images and location maps were affected, including UK, Germany, Russia and Scotland. In the confusion, many temporary fixes were attempted and my change to Template:Location map Scotland was backed out.
  • I have been asked for suggestions on how to take this further forward.

[edit] My response

  • I agree with and understand your reasons for backing out my changes. But I need to point out that a) there is a limit to how much time I can spend on this, b) after backing out my changes, you are now back to where you were months ago with a map that just doesn't work, c) at the end of this week I will be living in temporary accommodation under straitened circumstances and extremely limited internet access, d) you are asking for a high-quality map to a specific projection derived from a high-quality map with a different (non)projection, and that requires more technical ability that I or most people have. So my recommendations are as follows:

[edit] My recommendations

  • 1) I recommend that you reinstate my changes as of this. If you think it's too pixilated, then maybe you would like map E as of this diff. Either of these options will act as a temporary solution to stop Aberdeen, Lerwick and Brodick being located in the sea, and give you time to find a permanent solution as per below.
  • 2) I recommend that you contact the Wikipedia:Wikipedians/Cartographers, tell them your problem, and ask them to build you a better map as a permanent solution.

These recommendations are my best recommendations to move this project forward. Accept or reject them as you feel appropriate. But for the reasons described above, I cannot devote more time to this project. Regards, Anameofmyveryown 00:28, 17 September 2007 (UTC)

No problem getting into a major dazzle about this - hopefully we should have it sorted soon enough! WRT your response section I can easily deal with them in turn. a) I am happy to do the work, you don't need to invest any more time as you have already put in a lot. b) only for a couple of days, I am sure the good denizens of aberdeen and lerwick can hold for that long! c) That is ok, this doesn't really require a large amount of correspondence or net connectivity. d) I have access to the original Nasa data files and hence can derive 10,000 x 10,000 images out if they are needed at that resolution, and along with that I have advanced image editing abilities - so this is not a technical issue.
To move it forward, I will take care of the problem at the weekend. If all that is required is 150% vertical stretching of the original then that is straight and simple to do - I was fearing it was going to be some complex convolution matrix involved in the transformation. I will simply render a high res original (higher than will be used), stretch vertically , and then scale down to around 500 x 1000 for use in the template. Job done! (as a post script comment the STRM tiles are in geodetic latitude-longitude projection, as I originally transform them to UTM WGS84 to make them look sensible - hence this modification I presume, simply requires export and stretching rather than UTM transforming) SFC9394 20:50, 17 September 2007 (UTC)
I am pleased that you have undertaken to do the work involved, since I would like to see the job done. Your statement "...If all that is required is 150% vertical stretching of the original..." makes me concerned that you have misunderstood what I wrote above, since that is not what I said. I have rewritten the above to make my meaning plainer. As for the rest of your statement, I don't know what STRM tiles are, so I cannot comment meaningfully. As a guide, I would suggest that you try to produce a equidistant cylindrical projection map - i.e. one that closely matches the outline of map B or map C. If you can produce a equidistant cylindrical projection map, then that will work, and any linearly transformed (ie stretched) version of your equidistant cylindrical projection map will also work. If you can't produce a equidistant cylindrical projection map, then I would guess that your maps will not work. In the latter event, and if my recommendations above are not implemented, then I suggest you leave the existing map (map A) in place: the inaccuracies are annoying but not wildly out. Good luck, and I hope your labors of the weekend bear fruit. Regards, Anameofmyveryown 23:12, 17 September 2007 (UTC)

[edit] Changes Made

Ok, I have uploaded a new version - original equi. cynd. (which is what the SRTM are in) stretched by 150% vertically. I have modified the plot bounding co-ords to match what the map gives. 3 of them tally with secondary sources, but the westing (7.66) doesn't agree with what the topo tiles says ([1] - imageshack screenshot for convenience). I have gone with the 7.600 west as that is what the core data says, the discrepancy is an unknown. It seems to work with -7.60 and we no longer have floating cities in the sea! If there are any modifications required I have everything here. SFC9394 23:19, 21 September 2007 (UTC)

Aberdeen, Inverness, Stornoway, Lockerbie, Lerwick, Glasgow, Brodick, Edinburgh and Kirkwall all check out. Excellent! Well done young Jedi! Bill will be dead pleased when he comes back. Time for cake, I think...Anameofmyveryown 07:01, 22 September 2007 (UTC)