In the spirit of Blog Little Things and after reading WEBKID’s You Might Not Need QGIS earlier, here you go:
So you have thousands or millions of coordinates in “the wrong” or “that stupid” coordinate reference system and want to convert them to “the one you need”? Easily done with proj‘s cs2cs tool. You feed it a list of coordinates and tell it how you want them transformed and put out.
Let’s say you have these crazy accurate super coordinates in EPSG:4326 (WGS84) in a file called MyStupidCoordinates.txt (for example from copying columns out of Excel).
9.92510775592794303 53.63833616755876932
9.89715616602172332 53.61639299685715798
9.91541274879985579 53.63589289755918799
9.91922922611725966 53.63415202989637010
9.92072211107566382 53.63179675033637750
9.89998015840083490 53.62284810375095390
9.90427723676020832 53.60740624866674153
9.95012889485460583 53.64563499608360075
9.89590860878436196 53.62979225409544171
9.92944379841924452 53.60061248161031955
and you want them in the much superior and wonderfully metric EPSG:25832 (ETRS89 / UTM zone 32N). You simply use +init=sourceCRS +to +init=targetCRS. if you have no idea what CRS your coordinates are in, enjoy 5 minutes with http://projfinder.com/ and you will either know or you might want to take a walk (don’t forget to try them flipped though).
cs2cs +init=epsg:4326 +to +init=epsg:25832 MyStupidCoordinates.txt |
and it will print
561164.00 5943681.64 0.00
559346.79 5941216.81 0.00
560526.52 5943401.54 0.00
560781.36 5943211.12 0.00
560883.46 5942950.37 0.00
559524.51 5941937.29 0.00
559830.54 5940223.00 0.00
562807.40 5944515.43 0.00
559245.50 5942706.43 0.00
561505.49 5939488.65 0.00
You probably want more decimal places though, since your input coordinates were accurate down to the attodegree. For this, you can specify the output format with -f
cs2cs +init=epsg:4326 +to +init=epsg:25832 -f "%.17f" MyStupidCoordinates.txt |
561164.00100000295788050 5943681.64279999211430550 0.00000000000000000
559346.79200000269338489 5941216.80899999570101500 0.00000000000000000
560526.52400000276975334 5943401.53899999428540468 0.00000000000000000
560781.36300000245682895 5943211.12199999392032623 0.00000000000000000
560883.46400000224821270 5942950.37499999348074198 0.00000000000000000
559524.51200000231619924 5941937.29399999510496855 0.00000000000000000
559830.54200000269338489 5940223.00299999490380287 0.00000000000000000
562807.39800000295508653 5944515.43399999290704727 0.00000000000000000
559245.50000000221189111 5942706.42899999395012856 0.00000000000000000
561505.48800000257324427 5939488.65499999187886715 0.00000000000000000
Perfect!
You could direct these transformed coordinates into a new file called MyCoolCoordinates.txt by adding a redirection of its output:
cs2cs +init=epsg:4326 +to +init=epsg:25832 MyStupidCoordinates.txt > MyCoolCoordinates.txt |
You can find out more about cs2cs by reading its manpage:
man cs2cs |
PS: You can handle that Z coordinate, right?
