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maptrimp

Trim polygons to latitude-longitude quadrangle

Syntax

[latTrimmed,lonTrimmed] = maptrimp(lat,lon,latlim,lonlim)

Description

[latTrimmed,lonTrimmed] = maptrimp(lat,lon,latlim,lonlim) trims the polygons in lat and lon to the quadrangle specified by latlim and lonlim. latlim and lonlim are two-element vectors, defining the latitude and longitude limits respectively. lat and lon must be vectors that represent valid polygons.

Examples

collapse all

Read coastline data and display it on a map.

load coastlines
figure
mapshow(coastlon,coastlat,'DisplayType','polygon');

Trim the dataset.

latlim = [-50 50];
lonlim = [-100 50];
[latTrimmed,lonTrimmed] = maptrimp(coastlat,coastlon, ...
   latlim, lonlim);

Display the trimmed dataset.

figure
mapshow(lonTrimmed,latTrimmed, 'DisplayType', 'polygon');

Tips

maptrimp conditions the longitude limits such that:

  • lonlim(2) always exceeds lonlim(1)

  • lonlim(2) never exceeds lonlim(1) by more than 360

  • lonlim(1) < 180 or lonlim(2) > -180

  • Ensure that if the quadrangle span the Greenwich meridian, then that meridian appears at longitude 0.

Version History

Introduced before R2006a