# Geo

**URL:** https://discourse.julialang.org/c/domain/geo/18.md?page=3

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 4

---

## [What would be the best approach to handle large NetCDF sets?](https://discourse.julialang.org/t/what-would-be-the-best-approach-to-handle-large-netcdf-sets/102091)

<div class="topic-metadata">

**Author:** [@ThomasJulia](https://discourse.julialang.org/u/ThomasJulia)\
**Replies:** 10\
**Last updated:** [August 2, 2023, 10:58am UTC](https://discourse.julialang.org/t/what-would-be-the-best-approach-to-handle-large-netcdf-sets/102091 "2023-08-02T10:58:36Z")

</div>

Currently, we have python scripts able to handle large netcdf sets (100Go to 1To). Thanks to Dask and multithreading we was able to load and perform operations on chunk which would fit in memory. However, it is too slow …

---

## [How to resample (downscale) a one-hot encoded (boolean) raster?](https://discourse.julialang.org/t/how-to-resample-downscale-a-one-hot-encoded-boolean-raster/101828)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 6\
**Last updated:** [July 20, 2023, 1:51pm UTC](https://discourse.julialang.org/t/how-to-resample-downscale-a-one-hot-encoded-boolean-raster/101828 "2023-07-20T13:51:10Z")

</div>

Hello, I have “one-hot” encoded a 1x1km soil category raster, so I have a raster representing a specific soil class, 0 when is not in the class, and 1 otherwise. I would now downscale it to match my actual other data a…

---

## [Is there a convenient way to read netCDF datasets stored in nested groups when using NCDatasets.jl?](https://discourse.julialang.org/t/is-there-a-convenient-way-to-read-netcdf-datasets-stored-in-nested-groups-when-using-ncdatasets-jl/101589)

<div class="topic-metadata">

**Author:** [@haffner](https://discourse.julialang.org/u/haffner)\
**Replies:** 3\
**Last updated:** [July 14, 2023, 12:07am UTC](https://discourse.julialang.org/t/is-there-a-convenient-way-to-read-netcdf-datasets-stored-in-nested-groups-when-using-ncdatasets-jl/101589 "2023-07-14T00:07:22Z")

</div>

Hi, I’m relatively new to Julia and trying to use NCDatasets.jl to read satellite data stored in netCDF files. The data are stored in compound groups at the end of a path like this /BAND1\_RADIANCE/STANDARD\_MODE/GEODATA…

---

## [How do I get the bounds (or center) of a named region in GMT.jl](https://discourse.julialang.org/t/how-do-i-get-the-bounds-or-center-of-a-named-region-in-gmt-jl/101506)

<div class="topic-metadata">

**Author:** [@Philip\_Stuckey](https://discourse.julialang.org/u/Philip_Stuckey)\
**Replies:** 3\
**Last updated:** [July 13, 2023, 1:06am UTC](https://discourse.julialang.org/t/how-do-i-get-the-bounds-or-center-of-a-named-region-in-gmt-jl/101506 "2023-07-13T01:06:16Z")

</div>

Hi, so I’m messing around with making a map of California with a Lambert Conic Projection (my eventual goal is to make maps of the maidenhead locator for various states), unfortunately it’s at an angle unless I manually …

---

## [Display a variable makes it to be constant ? Rasters.jl bug?](https://discourse.julialang.org/t/display-a-variable-makes-it-to-be-constant-rasters-jl-bug/101157)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 5\
**Last updated:** [July 4, 2023, 10:22am UTC](https://discourse.julialang.org/t/display-a-variable-makes-it-to-be-constant-rasters-jl-bug/101157 "2023-07-04T10:22:18Z")

</div>

I got something really odd working with Raster 0.8, Julia 1.9: This is ok: julia\> using Rasters julia\> X = 2 2 julia\> X 2 julia\> typeof(X) Int64 but (new session): julia\> using Rasters julia\> X X julia\> X = 2 ERROR: …

---

## [Using ChatGPT to solve a challenging geo-science problem](https://discourse.julialang.org/t/using-chatgpt-to-solve-a-challenging-geo-science-problem/99067)

<div class="topic-metadata">

**Author:** [@pukpr](https://discourse.julialang.org/u/pukpr)\
**Replies:** 1\
**Last updated:** [June 23, 2023, 8:31pm UTC](https://discourse.julialang.org/t/using-chatgpt-to-solve-a-challenging-geo-science-problem/99067 "2023-06-23T20:31:28Z")

</div>

Blog post on using Julia and ChatGPT to solve a challenging geo-science problem. The post is almost completely a dialog between ChatGPT prompts and ChatGPT replies. I took the code it generated and ran and added in th…

---

## [How to set the font size for labels in a legend using GMT.jl](https://discourse.julialang.org/t/how-to-set-the-font-size-for-labels-in-a-legend-using-gmt-jl/97778)

<div class="topic-metadata">

**Author:** [@MJulia](https://discourse.julialang.org/u/MJulia)\
**Replies:** 7\
**Last updated:** [May 4, 2023, 12:35pm UTC](https://discourse.julialang.org/t/how-to-set-the-font-size-for-labels-in-a-legend-using-gmt-jl/97778 "2023-05-04T12:35:23Z")

</div>

I’m new to GMT.jl, I hope to adjust the font size of label (“data”) in the legend as in the following code: using GMT lines(1:12, 1:12, figsize=(6,4), legend=(label=“data”,pos=:LT,box=:none,), show=true) None of FONT\_…

---

## [Inviscid and incompressible Navier-Stokes equations in 2D implemented in Julia and compiled to WASM](https://discourse.julialang.org/t/inviscid-and-incompressible-navier-stokes-equations-in-2d-implemented-in-julia-and-compiled-to-wasm/97474)

<div class="topic-metadata">

**Author:** [@Alexander-Barth](https://discourse.julialang.org/u/Alexander-Barth)\
**Replies:** 10\
**Last updated:** [May 3, 2023, 4:02pm UTC](https://discourse.julialang.org/t/inviscid-and-incompressible-navier-stokes-equations-in-2d-implemented-in-julia-and-compiled-to-wasm/97474 "2023-05-03T16:02:20Z")

</div>

I recently made an online demo of the 2D Navier-Stokes equation running in a web-browser. https://alexander-barth.github.io/FluidSimDemo-WebAssembly/ My kids like to play with it to build dams and other obstacles in th…

---

## [What does it mean when yen\_k shows only one route?](https://discourse.julialang.org/t/what-does-it-mean-when-yen-k-shows-only-one-route/98132)

<div class="topic-metadata">

**Author:** [@Yao\_Vang](https://discourse.julialang.org/u/Yao_Vang)\
**Replies:** 11\
**Last updated:** [May 1, 2023, 10:08pm UTC](https://discourse.julialang.org/t/what-does-it-mean-when-yen-k-shows-only-one-route/98132 "2023-05-01T22:08:31Z")

</div>

Hello everyone, I’ve loaded a map via map = get\_map\_data(OSM\_File\_path, use\_cache=false, trim\_to\_connected\_graph=true) then randomly picked two nodeIDs to find out 5th shortest path between them. Since map.g stores a gr…

---

## [OpenStreetMapX: How to efficiently convert node\_id to vertex\_id?](https://discourse.julialang.org/t/openstreetmapx-how-to-efficiently-convert-node-id-to-vertex-id/98139)

<div class="topic-metadata">

**Author:** [@Yao\_Vang](https://discourse.julialang.org/u/Yao_Vang)\
**Replies:** 2\
**Last updated:** [May 1, 2023, 9:05am UTC](https://discourse.julialang.org/t/openstreetmapx-how-to-efficiently-convert-node-id-to-vertex-id/98139 "2023-05-01T09:05:24Z")

</div>

Hello all When calling any routing opetion in openstreetmapX it expects node\_id and in the answer it also returns node\_id. for example: m = get\_map\_data(File\_path, use\_cache=false, trim\_to\_connected\_graph=true ); a,b =…

---

## [Entry point for contributing to climate modeling projects?](https://discourse.julialang.org/t/entry-point-for-contributing-to-climate-modeling-projects/48856)

<div class="topic-metadata">

**Author:** [@crbinz](https://discourse.julialang.org/u/crbinz)\
**Replies:** 10\
**Last updated:** [April 17, 2023, 5:40pm UTC](https://discourse.julialang.org/t/entry-point-for-contributing-to-climate-modeling-projects/48856 "2023-04-17T17:40:07Z")

</div>

I’d like to spend some of my free time contributing to projects that help address the issue of climate change. My background is that I have (basically) no domain knowledge at all, but I have julia and modeling/simulation…

---

## [Create array of hexagons, place in index, and search by point](https://discourse.julialang.org/t/create-array-of-hexagons-place-in-index-and-search-by-point/97325)

<div class="topic-metadata">

**Author:** [@thk686](https://discourse.julialang.org/u/thk686)\
**Replies:** 11\
**Last updated:** [April 12, 2023, 2:31pm UTC](https://discourse.julialang.org/t/create-array-of-hexagons-place-in-index-and-search-by-point/97325 "2023-04-12T14:31:11Z")

</div>

I’ve been looking at JuliaGeo to how I might do the following: 1) create a tiled array of hexagons, 2) put them in a spatial index, and 3) be able to find which hexagon intersects a point. I have written this code in Boo…

---

## [Convert binary mask to shapefile](https://discourse.julialang.org/t/convert-binary-mask-to-shapefile/97322)

<div class="topic-metadata">

**Author:** [@chadagreene](https://discourse.julialang.org/u/chadagreene)\
**Replies:** 4\
**Last updated:** [April 11, 2023, 3:57pm UTC](https://discourse.julialang.org/t/convert-binary-mask-to-shapefile/97322 "2023-04-11T15:57:11Z")

</div>

I have a large (20,000 x 25,000) binary mask that defines the shape of an island. What’s the best way to convert the mask into a polygon and and save it as a shapefile?

---

## [Convert GADM.jl country file to GeoJSON.jl](https://discourse.julialang.org/t/convert-gadm-jl-country-file-to-geojson-jl/82654)

<div class="topic-metadata">

**Author:** [@alasaadstat](https://discourse.julialang.org/u/alasaadstat)\
**Replies:** 8\
**Last updated:** [April 5, 2023, 2:22pm UTC](https://discourse.julialang.org/t/convert-gadm-jl-country-file-to-geojson-jl/82654 "2023-04-05T14:22:55Z")

</div>

Hi, I would like to convert the loaded GADM.jl country polygon file to GeoJSON.jl so that I can plot this using GeoMakie.jl. I am aware that MeshViz.jl supports well the GADM.jl, but I would like to customize the plot an…

---

## [GDAL - Write KMZ file with transparency](https://discourse.julialang.org/t/gdal-write-kmz-file-with-transparency/97087)

<div class="topic-metadata">

**Author:** [@stefanomoro](https://discourse.julialang.org/u/stefanomoro)\
**Replies:** 1\
**Last updated:** [April 4, 2023, 9:54pm UTC](https://discourse.julialang.org/t/gdal-write-kmz-file-with-transparency/97087 "2023-04-04T21:54:30Z")

</div>

I’m trying to save a .kmz file from a dataset representing a DEM of an area stored in a GeoTiff file. My code is reading the DEM, transforming the CRS to UTM, and defining a subset based on coordinates. On this subset I…

---

## [How to find out sub-options under a module's option when using GMT in julia？](https://discourse.julialang.org/t/how-to-find-out-sub-options-under-a-modules-option-when-using-gmt-in-julia/96829)

<div class="topic-metadata">

**Author:** [@dk-zen](https://discourse.julialang.org/u/dk-zen)\
**Replies:** 4\
**Last updated:** [March 30, 2023, 7:39am UTC](https://discourse.julialang.org/t/how-to-find-out-sub-options-under-a-modules-option-when-using-gmt-in-julia/96829 "2023-03-30T07:39:03Z")

</div>

I’m new in GMT.jl. I follow the examples from Tutorial in Julia — GMT 6.4.0 documentation, and make a geographic map with a image pasted. It works. However, I don’t know how to query all options and suboptions under a m…

---

## [Create a \`Raster\` from OPeNDAP (netCDF)](https://discourse.julialang.org/t/create-a-raster-from-opendap-netcdf/96756)

<div class="topic-metadata">

**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 1\
**Last updated:** [March 29, 2023, 8:38am UTC](https://discourse.julialang.org/t/create-a-raster-from-opendap-netcdf/96756 "2023-03-29T08:38:43Z")

</div>

The netCDF library has a builtin capability of lazily reading data from an OPeNDAP server as the following code demonstrates. I was wondering how to tell Raster to do the same. using NCDatasets: NCDataset using Rasters …

---

## [Interaction of GeoJSON with GeoInterface methods](https://discourse.julialang.org/t/interaction-of-geojson-with-geointerface-methods/96535)

<div class="topic-metadata">

**Author:** [@Barget](https://discourse.julialang.org/u/Barget)\
**Replies:** 6\
**Last updated:** [March 24, 2023, 9:25am UTC](https://discourse.julialang.org/t/interaction-of-geojson-with-geointerface-methods/96535 "2023-03-24T09:25:35Z")

</div>

Hi, I’d like to read a .geojson file and perform some geometrical operations on the geometries (union, contains, etc.). Using LibGEOS or ArchGDAL works fine, but i’ve got some troubles with GeoJSON (maybe I’m missing s…

---

## [ArchGDAL.read error: GDALError (CE\_Failure, code 4):not recognized as a supported file format](https://discourse.julialang.org/t/archgdal-read-error-gdalerror-ce-failure-code-4-not-recognized-as-a-supported-file-format/95959)

<div class="topic-metadata">

**Author:** [@sunayana](https://discourse.julialang.org/u/sunayana)\
**Replies:** 4\
**Last updated:** [March 12, 2023, 10:08am UTC](https://discourse.julialang.org/t/archgdal-read-error-gdalerror-ce-failure-code-4-not-recognized-as-a-supported-file-format/95959 "2023-03-12T10:08:44Z")

</div>

Hi, I am currently stuck with a strange issue in GDAL and do not understand how to solve it. I have a method inside an IO module: read\_image\_file(filename::AbstractPath) = AG.read(string(filename)) This method is bein…

---

## [(help request) using ArchGDAL.gdalwarp() for resampling a raster dataset](https://discourse.julialang.org/t/help-request-using-archgdal-gdalwarp-for-resampling-a-raster-dataset/47039)

<div class="topic-metadata">

**Author:** [@vlandau](https://discourse.julialang.org/u/vlandau)\
**Replies:** 9\
**Last updated:** [March 10, 2023, 9:00pm UTC](https://discourse.julialang.org/t/help-request-using-archgdal-gdalwarp-for-resampling-a-raster-dataset/47039 "2023-03-10T21:00:08Z")

</div>

Hi all, I’m struggling to figure out how to use ArchGDAL.gdalwarp (currently only unsafe\_gdalwarp is documented). ArchGDAL.gdalwarp’s first parameter being a function is a bit confusing as well. Here’s the GDAL CLI vers…

---

## [How to create a RGB plot from three different TIF files?](https://discourse.julialang.org/t/how-to-create-a-rgb-plot-from-three-different-tif-files/92001)

<div class="topic-metadata">

**Author:** [@EmanuelCastanho](https://discourse.julialang.org/u/EmanuelCastanho)\
**Replies:** 17\
**Last updated:** [December 30, 2022, 4:47pm UTC](https://discourse.julialang.org/t/how-to-create-a-rgb-plot-from-three-different-tif-files/92001 "2022-12-30T16:47:47Z")

</div>

I have three TIF files that represent the Red, Green and Blue channels, they are pós-processed Sentinel-2 images. I read them with ArchGDAL and stacked them into a Float32 (554, 649, 3) matrix. How can I plot this stac…

---

## [How to create a new shapefile containing a few points](https://discourse.julialang.org/t/how-to-create-a-new-shapefile-containing-a-few-points/43454)

<div class="topic-metadata">

**Author:** [@rio](https://discourse.julialang.org/u/rio)\
**Replies:** 19\
**Last updated:** [December 26, 2022, 9:15am UTC](https://discourse.julialang.org/t/how-to-create-a-new-shapefile-containing-a-few-points/43454 "2022-12-26T09:15:32Z")

</div>

Hi, I have the latitude and longitude of a few points (in WGS84, EPS 4326) and I would like to save my points in a Esri shapefile. My 5 points have coordinates like Lon = -44 .+ rand(5); Lat = -23 .+ rand(5) Please,…

---

## [Best way to define lat, lon -or- projected x,y points that play nicely with GeoInterface.jl](https://discourse.julialang.org/t/best-way-to-define-lat-lon-or-projected-x-y-points-that-play-nicely-with-geointerface-jl/89795)

<div class="topic-metadata">

**Author:** [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)\
**Replies:** 4\
**Last updated:** [December 20, 2022, 10:04am UTC](https://discourse.julialang.org/t/best-way-to-define-lat-lon-or-projected-x-y-points-that-play-nicely-with-geointerface-jl/89795 "2022-12-20T10:04:52Z")

</div>

Is there a general standard for defining lat lon and projected points in the GeoJulia community such that they play nicely across packages? I looked through the GeoInterface.jl documentation but wasn’t able to locate tha…

---

## [New package to map GRIB files to the Unidata's Common Data Model v4 following the CF Conventions](https://discourse.julialang.org/t/new-package-to-map-grib-files-to-the-unidatas-common-data-model-v4-following-the-cf-conventions/32375)

<div class="topic-metadata">

**Author:** [@cvitolo](https://discourse.julialang.org/u/cvitolo)\
**Replies:** 18\
**Last updated:** [December 20, 2022, 7:23am UTC](https://discourse.julialang.org/t/new-package-to-map-grib-files-to-the-unidatas-common-data-model-v4-following-the-cf-conventions/32375 "2022-12-20T07:23:46Z")

</div>

Hi all! At ECMWF we are starting a new project/Julia package to map GRIB files (typically used in meteorology and climate science) to the Unidata’s Common Data Model v4 following the CF Conventions. We have already a P…

---

## [Function that returns the UTM zone?](https://discourse.julialang.org/t/function-that-returns-the-utm-zone/91568)

<div class="topic-metadata">

**Author:** [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)\
**Replies:** 1\
**Last updated:** [December 12, 2022, 8:28pm UTC](https://discourse.julialang.org/t/function-that-returns-the-utm-zone/91568 "2022-12-12T20:28:27Z")

</div>

Is there a Julia function that returns the UTM zone when given a latitude and longitude similar to Matlab’s utmzone?

---

## [Solving the direct geodesic problem with Proj.jl](https://discourse.julialang.org/t/solving-the-direct-geodesic-problem-with-proj-jl/91409)

<div class="topic-metadata">

**Author:** [@tcarion](https://discourse.julialang.org/u/tcarion)\
**Replies:** 3\
**Last updated:** [December 9, 2022, 7:47am UTC](https://discourse.julialang.org/t/solving-the-direct-geodesic-problem-with-proj-jl/91409 "2022-12-09T07:47:30Z")

</div>

Hi! I want to calculate the end point after moving some distance in some direction on an ellipsoid. I used to use the Proj4.jl function geod\_direct. As this higher level function has disappeared in Proj.jl, I’m trying …

---

## [How to drop the Z-dim of a shape file](https://discourse.julialang.org/t/how-to-drop-the-z-dim-of-a-shape-file/91390)

<div class="topic-metadata">

**Author:** [@luraess](https://discourse.julialang.org/u/luraess)\
**Replies:** 1\
**Last updated:** [December 7, 2022, 10:20pm UTC](https://discourse.julialang.org/t/how-to-drop-the-z-dim-of-a-shape-file/91390 "2022-12-07T22:20:46Z")

</div>

I would like to rasterise and draw border of a polygon from a Shapefile as in this example from Rasters.jl. I load my Shapefile as following julia\> vd\_bord = Shapefile.Handle("data/Shapefiles/Vaud.shp").shapes\[1\] Shape…

---

## [How to create a valid \`FeatureCollection\` I can interface with \`GeoJSON\`?](https://discourse.julialang.org/t/how-to-create-a-valid-featurecollection-i-can-interface-with-geojson/91197)

<div class="topic-metadata">

**Author:** [@ctrebbau](https://discourse.julialang.org/u/ctrebbau)\
**Replies:** 7\
**Last updated:** [December 4, 2022, 8:11pm UTC](https://discourse.julialang.org/t/how-to-create-a-valid-featurecollection-i-can-interface-with-geojson/91197 "2022-12-04T20:11:00Z")

</div>

using GeoJSON EPS = 5 MAD\_BOUNDS = (40.2257307, 40.6072783, -3.9536568, -3.4525022) grid = Dict("Lat" =\> range(MAD\_BOUNDS\[1\], MAD\_BOUNDS\[2\], EPS), "Lng" =\> range(MAD\_BOUNDS\[3\], MAD\_BOUNDS\[4\], EPS), …

---

## [How to convert DataFrame to Raster?](https://discourse.julialang.org/t/how-to-convert-dataframe-to-raster/90869)

<div class="topic-metadata">

**Author:** [@MiikkaT](https://discourse.julialang.org/u/MiikkaT)\
**Replies:** 8\
**Last updated:** [November 27, 2022, 11:18pm UTC](https://discourse.julialang.org/t/how-to-convert-dataframe-to-raster/90869 "2022-11-27T23:18:50Z")

</div>

I’m very new to Julia and coming from R background I’m now exploring spatial analysis in Julia. My current and maybe silly question is, how can I convert a dataframe that includes x and y coordinates to raster or raster …

---

## [LightOSM and OpenStreetMapX assigning inconsistent nearest node](https://discourse.julialang.org/t/lightosm-and-openstreetmapx-assigning-inconsistent-nearest-node/89633)

<div class="topic-metadata">

**Author:** [@ctrebbau](https://discourse.julialang.org/u/ctrebbau)\
**Replies:** 3\
**Last updated:** [November 6, 2022, 12:44am UTC](https://discourse.julialang.org/t/lightosm-and-openstreetmapx-assigning-inconsistent-nearest-node/89633 "2022-11-06T00:44:05Z")

</div>

100 randomly chosen real coordinates: pts = collect(zip(df.cLat, df.cLng))\[rand(1:size(df, 1), 100)\] Conversion of points to appropriate package types: losm\_pts = \[GeoLocation(pts\[i\]\[1\], pts\[i\]\[2\]) for i in 1:length(p…

[Previous page](https://discourse.julialang.org/c/domain/geo/18.md?page=2)

[Next page](https://discourse.julialang.org/c/domain/geo/18.md?page=4)