Add gallery example for plotting an RGB image from an xarray.DataArray #2641
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| """ | ||
| RGB Image | ||
| --------- | ||
| The :meth:`pygmt.Figure.grdimage` method can be used to plot Red, Green, Blue | ||
| (RGB) images, or any 3-band false color combination. Here, we'll use | ||
| :meth:`rioxarray.open_rasterio` to read a GeoTIFF file into an | ||
| :class:`xarray.DataArray` format, and plot it on a map. | ||
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| The example below shows a Worldview 2 satellite image over | ||
| `Lāhainā, Hawai'i during the August 2023 wildfires | ||
| <https://en.wikipedia.org/wiki/2023_Hawaii_wildfires#L%C4%81hain%C4%81>`_. | ||
| Data is sourced from a Cloud-Optimized GeoTIFF file hosted on | ||
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| `OpenAerialMap <https://map.openaerialmap.org>`_ under a | ||
| `CC BY-NC 4.0 <https://creativecommons.org/licenses/by-nc/4.0/>`_ license. | ||
| """ | ||
| import pygmt | ||
| import rioxarray | ||
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| ############################################################################### | ||
| # Read 3-band data from GeoTIFF into an xarray.DataArray object | ||
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| image = rioxarray.open_rasterio( | ||
| filename="https://oin-hotosm.s3.us-east-1.amazonaws.com/64d6a49a19cb3a000147a65b/0/64d6a49a19cb3a000147a65c.tif", | ||
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There was a problem hiding this comment. This GeoTiff file is almost 1 GB, which is too big to download. There was a problem hiding this comment. The next line |
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| overview_level=5, | ||
| ) | ||
| # Subset to area of Lāhainā in EPSG:32604 coordinates | ||
| image = image.rio.clip_box(minx=738000, maxx=755000, miny=2300000, maxy=2318000) | ||
| image | ||
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| ############################################################################### | ||
| # Plot the RGB imagery | ||
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| fig = pygmt.Figure() | ||
| fig.grdimage( | ||
| grid=image, | ||
| projection="x1:100000", | ||
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| frame=[r"WSne+tL@!a\225hain@!a\225, Hawai\047i on 9 Aug 2023", "af"], | ||
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There was a problem hiding this comment. Had to use the composite character There was a problem hiding this comment. I think that's fine. Maybe it's possible to avoid that the letters are too close to each other by using another font style? There was a problem hiding this comment. Agree with @michaelgrund, these unequally spaced letters are a bit strange. Looking at the example at https://docs.generic-mapping-tools.org/6.4/tutorial/session-2.html#gmt-tut-10, using the font Times-Roman does not lead to unequally spaced letters. There was a problem hiding this comment. Agree that the spacing looks weird. I've changed the font to Times-Roman at b516c19 and it looks a bit better now:
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| ) | ||
| fig.show() | ||
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Is it possible to make this work as a link to https://corteva.github.io/rioxarray/stable/rioxarray.html#rioxarray.open_rasterio?
If this is not easy to do, then we leave it as is. At least in the code example below, the link works.
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Ah yes, good catch. I used the wrong intersphinx directive, should be
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Ah, great. Thanks!