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knoflook 29e7f12a46 docs: improve documentation

2025-02-24 00:28:56 +01:00

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mapping cameras

todos:

limit to 5 queries per request - split into multiple files i guess
document the code
document how to use
return data in geojson, not regular json

queries and technicalities

how to import to qgis

once you have created the geojson files (consult the README.md file you can open it in qgis (Layer → Add Layer → Add Vector Layer → pick geojson data you exported)

then click on the imported layer and go to properties and make the line more visible

missing data from api

not all streets get returned. this is because the query is only asking for objects of type way of specific types (primary, secondary, highway, etc. can be checked in scripts/02-way-queries which doesn't include i.e. bridges. This is the script that has to be tweaked to get all the data we want

to see which ones appear in a specific dataset run

for i in working-data/04/*; do
  echo "---------- $i -----------"
  cat "$i" | jq ".elements[] | select(.type == \"way\") | .tags.name" | sort | uniq
  echo "\n\n"
done

compare against amount of lines in working-data/02/ with wc -l for each file and then we see which sets dont return all data then more investigation can happen and the query can be adjusted.

checking the data from gemeenteblad for mistakes

some of the street names are misspelled. to check for that i was using the following process. in the source-data/by-district directory i run a quick sed command for each neighbouhood to format data for pasting into a tool i.e. cat 10-ijsselmonde | sed 's/, /, Rotterdam\n/g' this returns a list like this (abbreviated for readability):

Aesopusviaduct, Rotterdam
Anthony Tijkenstraat, Rotterdam
Bierens de Haanweg, Rotterdam
Bollandstraat, Rotterdam
Bolnesserkade, Rotterdam
Burgemeester Molenaarstraat, Rotterdam
Cannenburchstraat, Rotterdam
Zuidkreek.

then i go into https://www.mapcustomizer.com/ and use the bulk import option to mark all these streets, adding , Rotterdam to the last street name so it looks like this

Aesopusviaduct, Rotterdam
Anthony Tijkenstraat, Rotterdam
Bierens de Haanweg, Rotterdam
Bollandstraat, Rotterdam
Bolnesserkade, Rotterdam
Burgemeester Molenaarstraat, Rotterdam
Cannenburghstraat, Rotterdam
Zuidkreek, Rotterdam

if you try these streets 2 of them will fail (bolnesserkade and cannenburghstraat). then you manually look these streets up in a search engine. in our case - Bolnesserkade is marked as being in Ridderkerk and Cannenburghstraat is misspelled. The first one i just ignore (can be added manually later, it's an edge case) the second one i just correct in the source file and make a comment about it.

AI-generated guide

Install QGIS

Download and install QGIS from the official QGIS website. Follow the installation instructions for your operating system.

Obtain Street Data

You can use OpenStreetMap data, which can be downloaded using tools like Geofabrik or Overpass Turbo.
For example, in Overpass Turbo:
Use a query like:

plaintext

   [out:json];
   area[name="City Name"]->.searchArea;
   way"highway";
   out body;

Click "Run" to execute the query and then export the results as GeoJSON or Shapefile.

Open QGIS and Load the Data

Open QGIS.
To load your street data:
Go to Layer > Add Layer > Add Vector Layer.
Select the file you downloaded and click Open.
Your streets should now appear on the map canvas.

Prepare Your List of Streets

Format your list of street names in a text file (CSV or plain text) or use the list directly within QGIS by creating a new attribute for the streets you want to highlight.
For example, if you use a CSV file, make sure it has a column with street names.

Load Your Street List

If using a CSV file:
Go to Layer > Add Layer > Add Delimited Text Layer.
Choose your CSV file, ensuring the street name column is correctly identified.
If you want to combine it directly within QGIS, skip this step.

Style the Streets

Open Layer Properties:
Right-click on the street layer in the Layers panel and choose Properties.
Change Styling:
In the Layer Properties window, go to the Symbology tab.
Change the symbology from Single symbol to Categorized if you want to style by categories (i.e., by street names).
For basic changes, you can also use Rule-based styling.
Click Add to create rules or categories.
If you categorized by street name, match the street names directly to colors.
For a rule-based approach, you can set conditions based on the street name attribute.
Example of Rule-Based Styling:
Click on Add Rule.
For the rule, set the condition (e.g., if the street name equals 'Main St', use a red color).
Repeat for all streets you want to highlight.
Click OK to apply the changes.

Add Basemap (Optional)

To add a base map:
Go to Web > QuickMapServices > Settings.
Click on Service and add a new service if necessary (e.g., OpenStreetMap).
After setting it up, use Web > QuickMapServices > OpenStreetMap to add the base map.

Export Your Map

Once you are satisfied with your visualization:
Go to Project > Import/Export > Export Map to Image or Export Map to PDF.
Choose your preferred format and set the options as needed.

Save Your Project

Don’t forget to save your QGIS project for future use by going to Project > Save.

Plugins

While you may not necessarily need plugins for basic street coloring, here are a couple that could enhance your experience:

MMM (Map Multi Measure): For measuring distances or areas on your map.
OpenLayers Plugin: To add additional background maps (though integrated methods in QGIS are often sufficient).
QuickMapServices: For easily adding various basemaps (this is already discussed above).

Additional Resources

QGIS comes with comprehensive documentation here that can be helpful as you get more familiar with the software.
Tutorials and videos on platforms like YouTube can help visualize some of the above steps.

By following these steps, you should be able to create a customized map in QGIS where specific streets stand out visually according to your requirements.

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