MATLAB: Display USGS DEM using geotiffread and mapshow

geotiffMapping Toolboxmapshow

Hi, I'm trying to use USGS DEMs in MATLAB but after reading it in with geotiffread, mapshow produces an error. Based on the documentation, I tried
[A, R] = geotiffread('NED_10340081')
figure
mapshow(A, R);
but I get
Error using mapshow
Expected input number 1, I or X or RGB, to be one of these types:
    uint8, uint16, double, logical
Instead its type was single.
Error in validateMapRasterData>parseImageInputs (line 109)
validateattributes(A, {'uint8', 'uint16', 'double', 'logical'}, ...
Error in validateMapRasterData>validateImageComponent (line 93)
        [A, R] = parseImageInputs(mapfcnname, dataArgs{:}, cmap, rules );
Error in validateMapRasterData (line 27)
        [Z, SpatialRef] =  validateImageComponent(mapfcnname, ...
Error in maprastershow (line 127)
[Z, SpatialRef, displayType, HGpairs] = ...
Error in mapshow (line 231)
h = showFcn(varargin{:});
My matrix A is of type single…is that the problem? and how do I fix this? Thanks

Best Answer

geotiffread results in a type 'single' but mapshow defaults to a 'image' that can only accept 'double' (and some other formations not including 'single'). Either A=double(A) or mapshow(A,R,'DisplayType','surface')
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