From: R. A. <ra...@gm...> - 2008-12-16 00:39:46
|
Hi All, I have some square images which were generated via WMS requests. I have imported them into Matplotlib via pil_to_array, and then display them in a Basemap instance where I have defined the projection as: m = Basemap(projection='cyl', lon_0=lon_0, llcrnrlon=ll_lon, llcrnrlat=ll_lat, urcrnrlon=ur_lon, urcrnrlat=ur_lat, suppress_ticks=False) While this works (it appears the tics are at the right places), the image is no longer square, and I wonder if my projection definition is correct. Can someone show me what the correct Basemap parameters are for working with images that are in EPSG:4326? Thanks, Roger |
From: Jeff W. <js...@fa...> - 2008-12-16 12:43:58
|
Roger André wrote: > Hi All, > > I have some square images which were generated via WMS requests. I > have imported them into Matplotlib via pil_to_array, and then display > them in a Basemap instance where I have defined the projection as: > > m = Basemap(projection='cyl', lon_0=lon_0, llcrnrlon=ll_lon, > llcrnrlat=ll_lat, urcrnrlon=ur_lon, > urcrnrlat=ur_lat, suppress_ticks=False) > > While this works (it appears the tics are at the right places), the > image is no longer square, and I wonder if my projection definition is > correct. > > Can someone show me what the correct Basemap parameters are for > working with images that are in EPSG:4326? > > Thanks, > > Roger Roger: The image will only be square if ur_lon-ll_lon = ur_lat-ll_lat (i.e. the longitude range equals the latitude range). Is this the case? -Jeff -- Jeffrey S. Whitaker Phone : (303)497-6313 NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 325 Broadway Boulder, CO, USA 80305-3328 |
From: R. A. <ra...@gm...> - 2008-12-16 17:26:15
|
Hi Jeff, I checked, and no the images are not geographically square. I wonder if I could approach this problem in a different way. Would it be possible for me to add tick marks and annotation to the image without using the Basemap module alone? My thinking is that I could bring the image into Matplotlib, define a square figure, and then manually define the size of the X and Y axes and label them. Is it possible to "decorate" an image this way, without using any projection support? Thanks for the help, Roger -- On Tue, Dec 16, 2008 at 4:43 AM, Jeff Whitaker <js...@fa...> wrote: > Roger André wrote: > >> Hi All, >> >> I have some square images which were generated via WMS requests. I have >> imported them into Matplotlib via pil_to_array, and then display them in a >> Basemap instance where I have defined the projection as: >> >> m = Basemap(projection='cyl', lon_0=lon_0, llcrnrlon=ll_lon, >> llcrnrlat=ll_lat, urcrnrlon=ur_lon, >> urcrnrlat=ur_lat, suppress_ticks=False) >> >> While this works (it appears the tics are at the right places), the image >> is no longer square, and I wonder if my projection definition is correct. >> >> Can someone show me what the correct Basemap parameters are for working >> with images that are in EPSG:4326? >> >> Thanks, >> >> Roger >> > > Roger: The image will only be square if ur_lon-ll_lon = ur_lat-ll_lat > (i.e. the longitude range equals the latitude range). Is this the case? > -Jeff > > -- > Jeffrey S. Whitaker Phone : (303)497-6313 > NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 > 325 Broadway Boulder, CO, USA 80305-3328 > > |
From: Jeff W. <js...@fa...> - 2008-12-16 17:54:07
|
Roger André wrote: > Hi Jeff, > > I checked, and no the images are not geographically square. I wonder > if I could approach this problem in a different way. Would it be > possible for me to add tick marks and annotation to the image without > using the Basemap module alone? My thinking is that I could bring the > image into Matplotlib, define a square figure, and then manually > define the size of the X and Y axes and label them. Is it possible to > "decorate" an image this way, without using any projection support? > > Thanks for the help, > > Roger Roger: Sure, you could do that. I'm not sure why you would want to display an image that's not geographically square as a square though. What's wrong with just letting Basemap show it as a rectange? -Jeff > -- > > On Tue, Dec 16, 2008 at 4:43 AM, Jeff Whitaker <js...@fa... > <mailto:js...@fa...>> wrote: > > Roger André wrote: > > Hi All, > > I have some square images which were generated via WMS > requests. I have imported them into Matplotlib via > pil_to_array, and then display them in a Basemap instance > where I have defined the projection as: > > m = Basemap(projection='cyl', lon_0=lon_0, llcrnrlon=ll_lon, > llcrnrlat=ll_lat, urcrnrlon=ur_lon, > urcrnrlat=ur_lat, suppress_ticks=False) > > While this works (it appears the tics are at the right > places), the image is no longer square, and I wonder if my > projection definition is correct. > > Can someone show me what the correct Basemap parameters are > for working with images that are in EPSG:4326? > > Thanks, > > Roger > > > Roger: The image will only be square if ur_lon-ll_lon = > ur_lat-ll_lat (i.e. the longitude range equals the latitude > range). Is this the case? > -Jeff > > -- > Jeffrey S. Whitaker Phone : (303)497-6313 > NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 > 325 Broadway Boulder, CO, USA 80305-3328 > > -- Jeffrey S. Whitaker Phone : (303)497-6313 Meteorologist FAX : (303)497-6449 NOAA/OAR/PSD R/PSD1 Email : Jef...@no... 325 Broadway Office : Skaggs Research Cntr 1D-113 Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg |
From: R. A. <ra...@gm...> - 2008-12-16 18:11:35
|
Ahh, because I have labels and other text already drawn on the image. Squishing it alters the shape of the letters. And I have potentially many of these coming out of WMS requests where I know the image size and corner coords, but I can't alter the basic nature of the image. What I'd like to do is use these images as figures in a report, so I need to be able to add Axes with labeling, and also Figure titles and text. Thanks, Roger -- On Tue, Dec 16, 2008 at 9:53 AM, Jeff Whitaker <js...@fa...> wrote: > Roger André wrote: > >> Hi Jeff, >> >> I checked, and no the images are not geographically square. I wonder if I >> could approach this problem in a different way. Would it be possible for me >> to add tick marks and annotation to the image without using the Basemap >> module alone? My thinking is that I could bring the image into Matplotlib, >> define a square figure, and then manually define the size of the X and Y >> axes and label them. Is it possible to "decorate" an image this way, >> without using any projection support? >> >> Thanks for the help, >> >> Roger >> > > Roger: Sure, you could do that. I'm not sure why you would want to > display an image that's not geographically square as a square though. > What's wrong with just letting Basemap show it as a rectange? > > -Jeff > >> -- >> >> >> On Tue, Dec 16, 2008 at 4:43 AM, Jeff Whitaker <js...@fa...<mailto: >> js...@fa...>> wrote: >> >> Roger André wrote: >> >> Hi All, >> >> I have some square images which were generated via WMS >> requests. I have imported them into Matplotlib via >> pil_to_array, and then display them in a Basemap instance >> where I have defined the projection as: >> >> m = Basemap(projection='cyl', lon_0=lon_0, llcrnrlon=ll_lon, >> llcrnrlat=ll_lat, urcrnrlon=ur_lon, >> urcrnrlat=ur_lat, suppress_ticks=False) >> >> While this works (it appears the tics are at the right >> places), the image is no longer square, and I wonder if my >> projection definition is correct. >> >> Can someone show me what the correct Basemap parameters are >> for working with images that are in EPSG:4326? >> >> Thanks, >> >> Roger >> >> >> Roger: The image will only be square if ur_lon-ll_lon = >> ur_lat-ll_lat (i.e. the longitude range equals the latitude >> range). Is this the case? >> -Jeff >> >> -- Jeffrey S. Whitaker Phone : (303)497-6313 >> NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 >> 325 Broadway Boulder, CO, USA 80305-3328 >> >> >> > > -- > Jeffrey S. Whitaker Phone : (303)497-6313 > Meteorologist FAX : (303)497-6449 > NOAA/OAR/PSD R/PSD1 Email : Jef...@no... > 325 Broadway Office : Skaggs Research Cntr 1D-113 > Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg > > |