Can I have coloured points in geoshow like in a scatter plot?

Hi all,

I want to plot DEM data with lat, lon and H as points with geoshow. The color shoud represent the elevation H like you can do it using scatter:

• scatter(lon, lat, 5, H)

Is it possible to do the same in geoshow without gridding? I can plot the coordinates as points with a certain colour, but how can I use H as colour?

• worldmap(rangeLat,rangeLon); geoshow(green, 'FaceColor', 'k','LineWidth',1);
• geoshow(lat,lon,'DisplayType','point','MarkerEdgeColor','r','Marker', '.');

Thanks for your help!

[weichao Wang]

same question, want to plot depth with different color!!

Answer 1

[Yue zhao]

I know this reply is a "LITTLE" late, but the question is common. Hope the reply would help future readers.

Yes, I find a way to do so. The main point in my answer is to use "makesymbolspec".

You can find how to use "makesymbolspec" in cases of lines in the following official tutorial: https://www.mathworks.com/help/map/ref/makesymbolspec.html

1) As for points, it is similar. But I assume you don't have a geospatial table for your points. You need to create one so that you could use "makesymbolspec" and "geoshow" more smoothly. It is very convenient and easy.

% I assume your lat, lon, H are all N-by-1 column vectors.

Shape = geopointshape(lat,lon);

% geopointshape is for creating points in the geospatial table

% lat,lon contains position for your data points

myMap = table(Shape,H);

% The geospatial table is created.

You can find the official document on "geospatial" here: https://www.mathworks.com/help/map/create-geospatial-tables.html

2) Then you can set points colors based on the "H" attribute in the geospatial table:

pointColor = makesymbolspec('Point',{'H',[min(H) max(H)],'Marker','.','MarkerEdgeColor',turbo});

% you can relax the limit [low_val high_val] a little bit if it helps, and change "caxis" accordingly.

% I used turbo here, you can change the colormap to many other types:

% https://www.mathworks.com/help/matlab/ref/colormap.html

% The 'H',[min(H) max(H)] pair is where you can set color based on required attribute.

% If you use '.' as the Marker, you have to use 'MarkerEdgeColor' not 'Color'.

3) Then you can show the points to your map:

geoshow(myMap,'DisplayType','Point','SymbolSpec',pointColor);

caxis([min(H) max(H)]);

colorbar;

This is what I produce for my dataset:

* For my case, "usamap" and "plotm" don't need the Mapping Toolbox, while "geoshow" does.