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Core
Set of common functions, to be used mostly by other packages. You won’t usually consume this package directly, but when using
AggregationTypes for widgets or when creating custom widgets.Tip: The computations performed internally by widgets use these functions. They can be useful in the context of new custom widgets (for example using a different charting library)
Contains a set of basic aggregation functions (count, min, max, sum, and average), used automatically for widgets and layers, see AggregationTypes. Functions are applicable to numbers and also objects using a numeric property.
- Input:
Param | Type | Description |
|---|---|---|
values | Array | Array of numbers or objects with a numerical property |
[key] | string | (optional). When using objects, name of the property to use for calculations |
- Returns:
Object- An object with Aggregation functions, which keys are everyAggregationTypesvalues - Example:
import { aggregationFunctions, AggregationTypes } from "@carto/react-core";
const values = [{ f: 1 }, { f: 2 }, { f: 3 }, { f: 4 }, { f: 5 }];
const avgFn = aggregationFunctions[AggregationTypes.AVG];
console.log(avgFn(values, "f")); // 3
Makes groups from features based in a column (
keysColumn) and applying an operation to the numeric values in a predefined column (valuesColumn).- Input:
Param | Type | Default | Description |
|---|---|---|---|
data | Array | | Features for calculations (plain objects with properties) |
valuesColumn | string | | Quantitative column for grouping (the name of a numeric property in the object) |
keysColumn | string | | Qualitative column for grouping (the name of a string property in the object) |
operation | string | |
- Returns:
Array- Grouped values - Example:
import { groupValuesByColumn, AggregationTypes } from "@carto/react-core";
const data = [
{ category: "A", population: 100 },
{ category: "A", population: 200 },
{ category: "B", population: 50 },
];
const groups = groupValuesByColumn(data, "population", "category", AggregationTypes.SUM);
console.log(groups); // output: [ { name: 'A', value: 300 }, { name: 'B', value: 50 }]
Categorizes numeric values as a histogram from a set of features, having the option of just calculating the frequency (with COUNT operation) or an aggregated operation on the features inside the bin (e.g., SUM).
- Input:
Param | Type | Description |
|---|---|---|
features | Array | Features for calculations (plain objects with properties) |
columnName | string | Quantitative column for calculations (the name of a number property in the object) |
ticks | Array | Array of numbers to build intervals (eg 1, 5, 10 will defines 4 intervals: <1, 1 to 5, 5 to 10 and >10) |
operation | string |
- Returns:
Array- Histogram data for each bin, derived from ticks - Example:
import { histogram, AggregationTypes } from "@carto/react-core";
const features = [
{ field: 1 },
{ field: 2 },
{ field: 2 },
{ field: 3 },
{ field: 3 },
{ field: 3 },
{ field: 4 },
{ field: 4 },
{ field: 5 },
];
const ticks = [2, 4, 6];
const h = histogram(features, "field", ticks, AggregationTypes.COUNT);
console.log(h); // [1, 5, 3, 0]
/*
histogram results as:
<2 --> 1 item
>=2 to <4 --> 5 items
>=4 to <6 --> 3 items
>=6 --> 0 items
*/
Receives an array of features and the properties that will be used for each axis, checks that properties are valid and returns a formatted array.
- Input:
Param | Type | Description |
|---|---|---|
features | Array | Features |
xAxisColumn | string | Property containing values for the X axis. |
yAxisColumn | string | Property containing values for the Y axis. |
- Returns:
Array- Formatted array. - Example:
import { scatterPlot } from "@carto/react-core";
const data = [
{ x: 0 }, // Missing y
{ y: 1 }, // Missing x
{ x: null, y: 1 }, // null x
{ x: 1, y: null }, // null y
{ x: 0, y: 0 }, // zero for both
{ x: 1, y: 2 }, // valid
{}, // no values for both
{ x: 2, y: 3 } // valid
];
sp = scatterPlot(data, 'x', 'y'));
console.log(sp); // [[0, 0],[1, 2],[2, 3]]; Invalid values are filtered out
Enum for the different types of aggregations, available for widgets.
- Options:
- COUNT
- SUM
- AVG
- MIN
- MAX
- Example:
import { AggregationTypes } from "@carto/react-core";
console.log(AggregationTypes.COUNT);
Last modified 7mo ago