pcolorps documentation

pcolorps is part of Antarctic Mapping Tools for Matlab (Greene et al., 2017). Click here for a complete list of functions in AMT.

Don't have Matlab's Mapping Toolbox? No problem. pcolorps works just like Matlab's pcolor or pcolorm functions, but plots georeferenced data in Antarctic polar stereographic coordinates (true latitude 71°S).

Syntax

```pcolorps(lat,lon,Z)
pcolorps(...,'PropertyName',PropertyValue,...)
pcolorps(...,'km')
pcolorps(...,'meridian',meridian)
h = pcolorps(...)```

Description

pcolorps(lat,lon,Z) constructs a surface to represent the data grid Z corresponding to a georeferenced lat,lon grid in South polar stereographic eastings and northings.

pcolorps(...,'PropertyName',PropertyValue,...) specifies any number of surface properties.

pcolorps(...,'km') plots in polar stereographic kilometers instead of the default meters.

pcolorps(...,'meridian',meridian) specifies a meridian longitude in the polar stereographic coordinate conversion. Default meridian is 0.

h = pcolorps(...) returns a column vector of handles to surface objects.

Example 1

Plot gridded georeferenced Bedmap2 data as a pseudocolor plot in cartesian polar stereographic coordinates:

```[lat,lon,bed] = bedmap2_data('bed','resolution','5 km');

pcolorps(lat,lon,bed)
xlabel('eastings (m)')
ylabel('northings (m)')
```

Enhance the appearance of topographic relief with shadem.

```shadem(3)
```

Example 2: Rotated coordinates

The example above plotted 5 km resolution data instead of the native 1 km resolution, because pcolor and pcolorps plots are actually quite slow for large datasets. By plotting 5 km resolution data, we actually cut the amount of datapoints by a factor of 25. If it were me, I would simply use imagesc instead of pcolorps in the example above, because Bedmap2 is natively gridded in polar stereographic coordinates and imagesc is much faster and uses less memory than pcolor.

If you have an irregular grid shape, or if the grid is regular in geo coordinates (and therefore not a perfect grid in polar stereographic), you'll definitely want to use pcolorps. Below we create a grid that is regular in latitude and longitude, get some corresponding z values for each grid point, and plot the bathymetry using pcolorps. I'm also putting the South Pole at the bottom of the map, and centering everything on the data by setting the meridian to 125 W:

```[Lat,Lon] = meshgrid(-75:0.01:-72.5,-137:0.01:-113);
Z = ibcso_interp(Lat,Lon);

figure
pcolorps(Lat,Lon,Z,'meridian',-125);