On Wed, Sep 03, 2008 at 06:11:56PM -0700, we recorded a bogon-computron collision of the <[EMAIL PROTECTED]> flavor, containing: > I was playing around with the latest offering from the National Hurricane > Center website which is a bundle of GIS files including shape files for the > three- and five-day projection cones of the various storms. To that end, I > was tinkering with a small dbfawk file for these shape files and sort of have > things working but with a few cosmetic issues I'd like to resolve (and > somehow can't).
> First, is there a way to resolve or reorder overlapping lines? The five-day > cone has polygon data for the three-day cone already inside it. The problem > is that the five-day cone ends up being drawn over the top of the three-day > cone so I can't see any of the three-day lines except for the very last arc > of the cone. This is only cosmetic since the three- and five-day cones > overlap completely but I was trying to get a red cone for the three-day and > a yellow one for the leftover bits in the five-day. You cannot do this using DBFAWK alone. What you want to do is to split up the shapefile based on attributes so the 5-day cones are in one file and the three-day in another. The best tool for the job would be ogr2ogr from the GDAL package with the "-where" option (e.g. ogr2ogr -where "CONE='three-day'" to_file.shp from_file.shp if there were a "CONE" attribute that had values "three-day" and "five-day") > Second, if two DBF files have the same fingerprint, is there a way to > distinguish between the files assuming that the file name is not known in > advance? No. If the dbf files have the same signature and you want to render them differently, you can't use signature-based dbfawk files. You have to use per-file based dbfawks (dbfawk file with same name as shapefile, but with "dbfawk" extension, in the same directory). > The reason for this question is the hurricane track is provided as a > separate file from the cone polygons and I was trying to display it in a > different color. But, the track and polygon files have identical DBF column > names. Unfortunately, that's one of the limitations of the signature-based dbfawk implementation. You could use ogr2ogr to change the shapefiles (e.g. strip out one of the fields you don't use so the files have distinct signatures), or just use per-file dbfawks. > Third, is there a way to kick Xastir and force it to reindex the maps and > refresh the screen non-interactively? If I get this working, a cron is going > to download the track, drop it in the maps directory and it should be able to > signal Xastir to reindex the maps and refresh the display so that the track > is updated. No, there is no such non-interactive option. You could probably change one of the USR signals so it did that instead of what they do now, but it's not in place now. -- Tom Russo KM5VY SAR502 DM64ux http://www.swcp.com/~russo/ Tijeras, NM QRPL#1592 K2#398 SOC#236 AHTB#1 http://kevan.org/brain.cgi?DDTNM "Argue for your limitations and sure enough, they're yours." -- R. Bach _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
