MATLAB: Add regions of statistical significance to a map plot

geoshowp-valueplotstatisticssurfacem

Hello,

I am using the following to map out a trend in data over a region:

ax = worldmap(latlim, lonlim);
S = shaperead('landareas','UseGeoCoords',true);
surfacem(lat, lon, inpdata)
geoshow([S.Lat], [S.Lon],'Color','black');

This should be simple but I am not seeing fora with it. Is there any way to now add in a surfacem plot of a matrix holding p-values of the trends? I would like to simply add a cross where the corresponding cell in the p-value matrix is < 0.05.

Thanks!

Best Answer

You'll find a few hatch filling functions on the File Exchange site. For example, the ones mentioned here.

Generally, to apply non-mapping toolbox plotting functions to maps, you'll need to do something like

[x,y] = mfwdtran(lat,lon); 
contourf(x,y,z)

and then you'd be able to use hatchfill as shown in the Pick-of-the-Week example.

Related Solutions

MATLAB: Cannot get a rectangle with linem

I get the same problem using Matlab 2012b. I've been finding a number of weird behaviors with Mapping Toolbox plotting functions lately. The first thing I always try as a workaround is to manually perform coordinate transformations, then plot using standard plotting functions. To do this,

Initialize a map,
Transform coordinates, then
plot using standard (non-mapping toolbox) plotting functions. Here's an example:

% Using these coordinates for your bounding box: 
lat = [-60 -60 60 60 -60]; 
lon = [-140 140 140 -140 -140];
% Initialize a map: 
worldmap('world') 
% Perform coordinate transformation: 
[x,y] = mfwdtran(lat,lon); 
% Plot using line instead of linem: 
line(x,y,'color','m')

However, the bounding box does not follow the curves of the projection, so you might want to densify the lines before doing coordinate transformation:

lat = [-60 -60:60 60:-1:-60]; 
lon = [-140 140*ones(1,121) -140*ones(1,121)];
worldmap('world') 
[x,y] = mfwdtran(lat,lon); 
line(x,y,'color','m')

MATLAB: Using worldmap in 0 to 360 longitude

Instead of using worldmap, use axesm to manually create an axis with the limits you want:

 % Some fake data
 data = peaks(50);
 lat = linspace(-90,90,50);
 lon = linspace(0, 360, 50);
 % Plot the map
 axesm('robinson', 'maplonlimit', [0 360], 'frame', 'on');
 geoshow('landareas.shp', 'facecolor', 'none');
 contourm(lat, lon, data);

Best Answer

Related Solutions

MATLAB: Cannot get a rectangle with linem

MATLAB: Using worldmap in 0 to 360 longitude

Related Question