The itslive_imagesc function plots ITS_LIVE data in regionally projected map coordinates.
itslive_imagesc(region)
itslive_imagesc(region,variable)
itslive_imagesc(...,'alpha',alpha)
itslive_imagesc(...,filepath=path)
h = itslive_imagesc(...)itslive_imagesc(region) plots ITS_LIVE ice speed as an imagesc object for the specified ITS_LIVE mosaic region. For a map of ITS_LIVE regions, type itslive_regions.
itslive_imagesc(region,variable) plots any ITS_LIVE variable such as 'v', 'vx', 'vy', 'vx_error', 'landice', etc. If a figure is open and axes are current before calling itslive_imagesc, only enough data are loaded to fill the extents of the current axes. If no axes are current before calling itslive_imagesc, the entire region is loaded and plotted. Note: Plotting an entire large region such as Antarctica might take several seconds.
itslive_imagesc(...,'alpha',alpha) sets the transparency to a value between 0 (totally transparent) and 1 (totally opaque). Default value is 1, (except for NaNs, which are always set to 0).
itslive_imagesc(...,filepath=path) specifies a directory where the velocity mosaic data reside.
h = itslive_imagesc(...) returns a handle h of the image object.
Make a map of Greenland's velocity. Greenland corresponds to ITS_LIVE region 5:
figure
itslive_imagesc(5)
set(gca,'colorscale','log')
clim([1 10e3])
exportgraphics(gcf,'itslive_imagesc_documentation_greenland.jpg')
In the example above, we plotted all the data for an entire region. But often times, you just want enough data to fill a map of a small region. To minimize memory requirements and maximize speed, initialize a map and set its extents before calling itslive_imagesc.
In the example below, we'll use mapzoomps function from Antarctic Mapping Tools to set the spatial extents of the map. If you're working on a region other than Antarctica, you can simply use the axis command to set axis extents to your liking. Below, we're also using modismoa from my MODIS Mosaic of Antarctica repo to create a background image.
Below we're setting the alpha value to 0.8, which makes the ice velocity colors slightly transparent, letting the texture from the MODIS MOA image shine through.
mapzoomps('pine island glacier')
modismoaps('contrast','low')
itslive_imagesc(19,'v','alpha',0.8)
set(gca,'colorscale','log')
clim([1 3000])
exportgraphics(gcf,'itslive_imagesc_documentation_pig.jpg')
The MATLAB functions in this repo and this documentation were written by Chad A. Greene of NASA/JPL. The NASA MEaSUREs ITS_LIVE project is by Alex S. Gardner and the ITS_LIVE team.