com.github.mrdimosthenis.synapses.Codec Maven / Gradle / Ivy
package com.github.mrdimosthenis.synapses;
import java.util.Arrays;
import java.util.Map;
import java.util.stream.Stream;
import synapses.custom.AttributeWithFlag;
import synapses.jvm.CodecJ;
/**
* The constructors and methods of codecs.
*
* Create a codec:
*
* {@code
* Map setosa = Map.of(
* "petal_length", "1.5",
* "species", "setosa"
* );
*
* Map versicolor = Map.of(
* "petal_length", "3.8",
* "species", "versicolor"
* );
*
* Stream dataset = Arrays.stream(new Map[]{setosa, versicolor});
*
* Attribute[] attributes = {
* new Attribute("petal_length", false),
* new Attribute("species", true)
* };
*
* Codec codec = new Codec(attributes, dataset);
* }
*
*
* Encode a data point:
*
* {@code
* codec.encode(setosa);
* }
*
*
*
* Decode a data point:
*
* {@code
* codec.decode(new double[]{0.0, 1.0, 0.0});
* }
*
*
*
* Get the JSON representation of the codec:
*
* {@code
* codec.json();
* }
*
*
*/
public class Codec {
CodecJ contents;
/**
* Creates a codec by consuming a stream of data points.
*
* @param attributes An array of attributes that defines their names and types (discrete or not).
* @param datapoints A stream that contains the data points.
*/
public Codec(Attribute[] attributes,
Stream> datapoints) {
AttributeWithFlag[] keysWithDiscreteFlags =
Arrays.stream(attributes)
.map(attribute ->
new AttributeWithFlag(attribute.name, attribute.flag)
).toArray(AttributeWithFlag[]::new);
contents = CodecJ.apply(keysWithDiscreteFlags, datapoints);
}
/**
* Creates a codec by parsing its JSON representation.
*
* @param json The JSON representation of a codec.
*/
public Codec(String json) {
contents = CodecJ.apply(json);
}
/**
* Encodes a data point.
*
* @param datapoint A data point as a map of strings.
* @return The encoded data point as an array of numbers between 0.0 and 1.0.
*/
public double[] encode(Map datapoint) {
return contents.encode(datapoint);
}
/**
* Decodes a data point.
*
* @param encodedValues An encoded data point as an array of numbers between 0.0 and 1.0.
* @return The decoded data point as a map of strings.
*/
public Map decode(double[] encodedValues) {
return contents.decode(encodedValues);
}
/**
* The JSON representation of the codec.
*
* @return The JSON representation of the codec.
*/
public String json() {
return contents.json();
}
}