CONCOORD Name
CONCOORD Purpose
Convert between two linear coordinate systems.
Category
Calling Sequence
concoord, x1, y1, x2, y2 Inputs
x1,y1 = input coordinates. in
Keyword Parameters
Keywords
/ROUND means round output to nearest integers.
Intended for pixel coordinates.
/TO_1 the input point(s), x1,y1, are in system 2 and are
to be converted to system 1. /TO_1 is the default.
/TO_2 the input point(s), x1,y1, are in system 1 and are
to be converted to system 2.
/INIT means initialize coordinate transformations.
In this case x1,y1 are the known reference point
coordinates in system 1, and x2,y2 are the known
reference point coordinates in system 2.
At least 3 non-colinear reference points are needed
to define the coordinate transformations, more are
ok. So for /INIT all 4 parameters are inputs and
arrays of at least 3 elements.
NAME1=nm1, NAME2=nm2 Optional coordinate system names,
def=system 1 and system 2. Only on /INIT.
Use /SYSTEMS to display system names at a later time.
Very useful to make the correct calls clear.
Outputs
x2,y2 = output coordinates. out
Common Blocks
concoord_com Notes
Notes: Example for pixel coordinates and lat/long:
concoord,ix,iy,lng,lat,/init,name1='Pixels',name2='Long/lat'
ix,iy are arrays of ref pt pixel coord, lng,lat are
arrays of ref pt long, lat.
concoord,lng,lat,ix,iy,/to_1,/round
From long,lat find pixel coordinates.
Modification History
R. Sterner, 1996 Oct 2
R. Sterner, 2010 May 03 --- Converted arrays from () to [].
Copyright (C) 1996, Johns Hopkins University/Applied Physics Laboratory
This software may be used, copied, or redistributed as long as it is not
sold and this copyright notice is reproduced on each copy made. This
routine is provided as is without any express or implied warranties
whatsoever. Other limitations apply as described in the file disclaimer.txt.