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57 lines
2.1 KiB
Plaintext
57 lines
2.1 KiB
Plaintext
{
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"name": "geometry_overlay_nearest",
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"type": "function",
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"groups": ["GeometryGroup"],
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"description": "This returns an array of results of an expression evaluated on features from a different layer ordered BY DISTANCE to the current feature, or, if no expression if provided, simply returns whether at least one feature from the other layer was found. Note : this function can be slow and consume a lot of memory for large layers.",
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"arguments": [
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{
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"arg": "layer",
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"description": "the other layer"
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},
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{
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"arg": "expression",
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"description": "an optional expression to evaluate on the features from the other layer (if not set, the function will just return a boolean indicating whether there is at least one match)",
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"optional": true
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},
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{
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"arg": "filter",
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"description": "an optional expression to filter the matching features (if not set, all features will be returned)",
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"optional": true
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},
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{
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"arg": "limit",
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"description": "an optional integer to limit the number of matching features (if not set, only the nearest feature will be returned)",
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"optional": true
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},
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{
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"arg": "max_distance",
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"description": "an optional maximum distance to limit the number of matching features (if not set, only the nearest feature will be returned)",
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"optional": true
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},
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{
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"arg": "cache",
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"description": "set this to true to build a local spatial index (most of the time, this is unwanted, unless you are working with a particularly slow data provider)",
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"optional": true,
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"default": false
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}
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],
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"examples": [
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{
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"expression": "geometry_overlay_nearest('regions')",
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"returns": "True"
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},
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{
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"expression": "geometry_overlay_nearest('regions', name)",
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"returns": "['South Africa', 'Africa', 'World']"
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},
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{
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"expression": "geometry_overlay_nearest('regions', name, name != 'World')",
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"returns": "['South Africa', 'Africa']"
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},
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{
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"expression": "geometry_overlay_nearest('regions', name, limit:=1)",
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"returns": "['South Africa']"
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}
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]
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}
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