wmsread(wms::WMS; layer=?, kwargs...)

Read the layer number provided by the service from which the wms type was created.

Parameters

• wms: A WMS type obtained from the wmsinfo function.

• layer: The layer number or layer name of interest from those provided by the WMS service. That is, both of these forms are allowed: layer=3 or layer="Invented layer name"

kwargs is the keywords/values pairs used to set

• region | limits: The region limits. Options are:

  • A Tuple or Array with 4 elements defining the (xmin, xmax, ymin, ymax) or a string defining the limits in all ways that GMT can recognize.

  • When the layer has the data projected, we can pass a Tuple or Array with 3 elements (lon0, lat0, width), where first two set the center of a square in geographical coordinates and the third (width) is the width of that box in meters.

  • A $mosaic$ tile name in the form $X,Y,Z$ or a quadtree. Example: $region="7829,6374,14"$. See the $mosaic$ function manual for more information. This form also sets the default cellsize for that tile. NOTE: this is a geographical coordinates only that implicitly sets $geog=true$. See below on how to change the default resolution.

• cellsize | pixelsize | resolution | res: Sets the requested cell size in meters [default]. Use a string appended with a 'd' (e.g. resolution="0.001d") if the resolution is given in degrees. This way works only when the layer is in geogs.

• zoom or refine: When the region is derived from a $mosaic$ tile name, the default is to get an image with 256 columns and n rows where n depends on latitude. So, either the area is large and consequently the resolution is low, or the inverse (small area and resolution is high). To change this status, use the zoom or refine options.

  • zoom: an integer >= 1 that for each increment duplicates the base resolution by 2. e.g., zoom=2 quadruplicates the default resolution. This option is almost redundant with the refine, but is offered for consistency with the $mosaic$ function.

  • refine: an integer >= 2 multiplication factor that is used to increment the resolution by factor. e.g., refine=2 duplicates the image resolution.

• size: Alternatively to the the cellsize use this option, a tuple or array with two elements, to specify the image dimensions. Example, size=(1200, 100) to get an image with 1200 rows and 100 columns.

• time: Some services provide data along time. Use this option to provide a time string as provided by DateTime. For example: time=string(DateTime(2021,10,29))

• geog | force_geog | forcegeog: Force the requested layer to be in geographical coordinates. This is useful when the data is in projected coordinates (check that by asking the contents of wms.layer[layer].srs) but want to pass a region in geogs. Warning: there is no guarantee that this always works.

Returns

A GMTimage

Examples

wms = wmsinfo("http://tiles.maps.eox.at/wms?")
img = wmsread(wms, layer=3, region=(-10,-5,37,44), pixelsize=500);

# Retrieve and display a MODIS image
wms = wmsinfo("https://gibs-c.earthdata.nasa.gov/wms/epsg4326/best/wms.cgi");
img = wmsread(wms, layer="MODIS_Terra_CorrectedReflectance_TrueColor", region=(9,22,32,43), time="2021-10-29T00:00:00", pixelsize=750);
imshow(img, proj=:guess)