How do I hide contour lines that overlap my map objects?

How do I hide contour lines that overlap my map objects?

When I display my data as contour plots on a map, some contour lines overlap with the map objects such as land and islands. How do I make them hide under the map objects? The following code shows this overlap:

load topo

axesm robinson; framem

[c,h]=contorm(topo,topolegend);

displaym(worldlo('POpatch'))

Answer 1

[MathWorks Support Team]

The reason the contour lines are not getting hidden is that the patches and the contour lines are on the same Z level (the value is 0 by default). In order to have the contours hidden under the patches, the contours must be at a lower Z level than the patches. You can use the ZDATAM function to accomplish this. The following code is an example of how this works:

%

load topo;

axesm robinson; framem;

[c,h]=contorm(topo,topolegend);

displaym(worldlo('POpatch'));

title('Contours Overlap');

figure;

axesm robinson; framem

[c,h]=contorm(topo,topolegend);

displaym(worldlo('POpatch'));

zdatam(handlem('allline'),-1)

title('Contours hidden behind map objects');