convert_to_csv_2d

convert_to_csv_2d#

Overview#

The convert_to_csv_2d tool is a utility script for converting 2D netCDF or GeoJSON files to a CSV format. It extracts the essential coordinate data (x, y) and includes any associated metadata or attributes.

In this tutorial, we assume yu want to convert a 2D netCDF file (example.nc) or GeoJSON file (example.geojson) from the /sample_files/2d directory to a CSV file.

Steps#

2. Run the convert_to_csv_2d Script#

Use the convert_to_csv_2d script to convert the example.nc or example.geojson file to CSV format:

For a netCDF File:#

../../src/convert_to_csv_2d.py -i example.nc -o example.csv

For a GeoJSON File:#

../../src/convert_to_csv_2d.py -i example.geojson -o example.csv

Command Breakdown#

  • -i example.nc or -i example.geojson: Specifies the name of the input file to convert.

  • -o example.csv: Specifies the name of the output CSV file.

Note: The output file will contain coordinate columns (x, y) and any additional metadata or attributes from the original file.

3. Verify the Output Files#

After running the script, you should see the corresponding CSV file in the same directory as your input file.

Example Outputs#

Input GeoJSON File#

Input: example.geojson#

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": { "name": "Feature1", "value": 10 },
      "geometry": {
        "type": "Point",
        "coordinates": [102.0, 0.5]
      }
    },
    {
      "type": "Feature",
      "properties": { "name": "Feature2", "value": 20 },
      "geometry": {
        "type": "LineString",
        "coordinates": [
          [103.0, 1.0],
          [104.0, 2.0]
        ]
      }
    }
  ]
}

Output CSV File#

Output: example.csv#

name,value,x,y
Feature1,10,102.0,0.5
Feature2,20,103.0,1.0
Feature2,20,104.0,2.0

Input netCDF File#

Input: example.nc#

The netCDF file example.nc is assumed to contain 2D data variables (x, y) along with associated attributes or metadata.

Output CSV File#

Output: example.csv#

x,y,temperature,pressure
102.0,0.5,25.6,1013.2
103.0,1.0,26.1,1012.8
104.0,2.0,27.0,1011.5

Notes#

  1. Handling Missing Values:

    • Any missing values in the input file are represented as NaN in the output CSV.

  2. Supported Geometry Types (GeoJSON):

    • The script supports Point and LineString geometry types.

    • For multi-point geometries like LineString, each point is represented as a separate row in the CSV.

  3. netCDF Data Extraction:

    • The script extracts coordinate data (x, y) and all 2D attributes or variables in the netCDF file.

  4. Flexibility:

    • The script dynamically detects the file type (netCDF or GeoJSON) without relying on file extensions.

  5. Output Columns:

    • GeoJSON: Includes properties (name, value, etc.) and coordinates (x, y).

    • netCDF: Includes variables and their respective coordinate data (x, y).

Troubleshooting#

  • Ensure that the input file is a valid 2D netCDF or GeoJSON file.

  • Check that the /sample_files/2d directory contains the file you want to convert.

  • If encountering issues, run the script with the -h option to display the help message:

    ../../src/convert_to_csv_2d.py -h

This guide ensures that you can seamlessly convert 2D netCDF and GeoJSON files to CSV format. For further assistance, feel free to consult the script documentation.

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