| Re: map_proj_inverse question [message #74383] |
Wed, 12 January 2011 11:10 |
David Fanning
Messages: 11724
Registered: August 2001
|
Senior Member |
|
|
nata writes:
> Thank you David, I can get the lat/lon values of the mouse position
> doing:
>
> result=CONVERT_COORD(event.X,event.Y,/DEVICE,/TO_DATA)
>
> The problem I have is that my map coordinate system is not set up. So
> when I call CONVERT_COORD I obtain the following message :
> % CONVERT_COORD: Window is closed and unavailable.
Yes, this is one reason I created the MapCoord object
in the Catalyst Library. I was doing a lot of map
projections in widget programs and I needed to be able
to make sure the map data coordinate system was "alive"
when I needed it. Simply calling the Draw method on the
MapCoord object restores the data coordinate system without
actually drawing anything.
WSet, info.mapWindow
info.mapCoord -> Draw
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
|
|
|
|
| Re: map_proj_inverse question [message #74384 is a reply to message #74383] |
Wed, 12 January 2011 11:00  |
natha
Messages: 482
Registered: October 2007
|
Senior Member |
|
|
Sorry guys,
There is a mistake on my formula :
X=event.X/dim[0]*uv_box_lenght[0] + !map.UV_BOX[0]
Y=event.Y/dim[1]*uv_box_lenght[1] + !map.UV_BOX[1]
Now, this is correct ! :P
nata
|
|
|
|
| Re: map_proj_inverse question [message #74385 is a reply to message #74384] |
Wed, 12 January 2011 10:53 |
natha
Messages: 482
Registered: October 2007
|
Senior Member |
|
|
Thank you David, I can get the lat/lon values of the mouse position
doing:
result=CONVERT_COORD(event.X,event.Y,/DEVICE,/TO_DATA)
The problem I have is that my map coordinate system is not set up. So
when I call CONVERT_COORD I obtain the following message :
% CONVERT_COORD: Window is closed and unavailable.
I'm creating my images in a Z-buffer and when I restore the X device I
lose the map coordinate system. However, I have a copy of the !map
structure.
Is there a way to retrieve the lat/lon without using CONVERT_COORD ?
Thank you,
nata
|
|
|
|
| Re: map_proj_inverse question [message #74386 is a reply to message #74385] |
Wed, 12 January 2011 10:15 |
David Fanning
Messages: 11724
Registered: August 2001
|
Senior Member |
|
|
nata writes:
> I'm setting a projection using MAP_SET (IDL 7.1), after that I want to
> retrieve the lat/lon values of the mouse position.
> What I'm doing is the following :
>
> 1) I retrieve the mouse position, using event.X and event.Y
> 2) After that, I normalize the X,Y position, taking in account the
> UV_BOX of the map structure
>
> uv_box_lenght=[!map.UV_BOX[2]-!map.UV_BOX[0],!map.UV_BOX[3]- !
> map.UV_BOX[1]]
>
> X=event.X/dim[0]*uv_box_lenght[0] + uv_box_lenght[0]
> Y=event.Y/dim[1]*uv_box_lenght[1] + uv_box_lenght[1]
>
> 3) And I calculate the lat/lon values using map_proj_inverse
>
> PRINT, MAP_PROJ_INVERSE(X,Y,MAP_STRUCTURE=!map)
>
> Mmmmh !!!! Something is not working well because the values I obtain
> are incorrect.
> What am I missing ?
If you have a map coordinate system set up, just
use Convert_Coord to convert your device coordinates
to data coordinates. If these are in projected meters
(I hope so!), then just use Map_Proj_Inverse to convert
these to lat/lon.
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
