data.DataFrame Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Jacob Rachiele
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
* and associated documentation files (the "Software"), to deal in the Software without restriction
* including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense
* and/or sell copies of the Software, and to permit persons to whom the Software is furnished to
* do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Contributors:
*
* Jacob Rachiele
*/
package data;
import java.util.*;
/**
*
* A potentially heterogeneous collection of columns of data. This class is mutable and not thread-safe. The
* immutable and thread-safe version of this class is {FixedDataFrame}.
*
* @author Jacob Rachiele
* Date: Dec 07 2016
*/
final class DataFrame {
private final Map> columnIdMap;
private final Map, Object> columnMap;
/**
* Create a new empty dataframe with the default column capacity. The column capacity will grow and
* shrink as necessary.
*/
DataFrame() {
this.columnIdMap = new HashMap<>();
this.columnMap = new HashMap<>();
}
/**
* Create a new empty dataframe with the given initial column capacity. The column capacity will grow and shrink
* as necessary.
* @param numColumns the initial column capacity.
*/
DataFrame(final int numColumns) {
this.columnIdMap = new HashMap<>(numColumns);
this.columnMap = new HashMap<>(numColumns);
}
public int size() {
return this.columnMap.size();
}
public Set getColumnIds() {
return this.columnIdMap.keySet();
}
/**
* Add the array of the given type to the data frame.
* @param id the unique id of the new column.
* @param type the class type of the data in the array.
* @param instance the array of data.
* @param the type of the data in the array.
*/
public void add(final String id, final Class type, final T[] instance) {
if (type == null) {
throw new NullPointerException("The class type was null.");
}
if (columnIdMap.containsKey(id)) {
throw new IllegalArgumentException("The column id, " + id + ", already exists. The column id must be unique.");
}
ColumnInfo colInfo = new ColumnInfo<>(id, type);
columnIdMap.put(id, colInfo);
columnMap.put(colInfo, instance);
}
/**
* Add the array of the given type to the data frame.
* @param id the unique id of the new column.
* @param type the class type of the data in the array.
* @param instance the array of data.
* @param the type of the data in the array.
*/
void replace(final String id, final Class type, final T[] instance) {
if (type == null) {
throw new NullPointerException("The class type was null.");
}
if (!columnIdMap.containsKey(id)) {
throw new IllegalArgumentException("The column id, " + id + ", doesn't exist, so there is nothing to replace.");
}
ColumnInfo oldInfo = columnIdMap.get(id);
columnMap.remove(oldInfo);
ColumnInfo colInfo = new ColumnInfo<>(id, type);
columnIdMap.put(id, colInfo);
columnMap.put(colInfo, instance);
}
/**
* Add the array of the given type to the data frame.
* @param id the id of the new column.
* @param type the class type of the data in the array.
* @param instance the list of data.
* @param the type of the data in the list.
*/
void add(final String id, Class type, List instance) {
if (type == null) {
throw new NullPointerException("The class type was null.");
}
T[] asArray = type.cast(instance.toArray());
ColumnInfo colInfo = new ColumnInfo<>(id, type);
columnIdMap.put(id, colInfo);
columnMap.put(colInfo, asArray);
}
/**
* Remove and return the specified column from this dataframe.
* @param id the identifier of the column to remove.
* @param type the class type of the column to remove.
* @param the type of the data in the column to remove.
* @return the removed column.
*/
T[] remove(final String id, Class type) {
return type.cast(this.columnMap.remove(new ColumnInfo<>(id, type)));
}
/**
* Retrieve the data in the specified column as a list of the given type.
* @param id the identifier of the column to retrieve.
* @param type the class type of the data in the column.
* @param the type of the data in the column.
* @return the data in the ith column as a list of the given type.
*/
List getList(final String id, final Class type) {
ColumnInfo info = new ColumnInfo<>(id, type);
T[] column = get(info);
return Arrays.asList(column);
}
ColumnInfo getColumnInfo(final String id) {
return this.columnIdMap.get(id);
}
Class getColumnClass(final String id) {
return columnIdMap.get(id).clazz;
}
String getColumnClassName(final String id) {
return columnIdMap.get(id).clazz.getSimpleName();
}
/**
* Retrieve the data in the specified column as an array of the given type.
* The array class type is required for type safety. For an example of how to use this method,
* Double[] columnData = ne w
* @param id the identifier of the column to retrieve.
* @param type the class type of the data in the array.
* @param the type of the data in the array.
* @return the data in the ith column as an array of the given type.
*/
public T[] get(final String id, final Class type) {
ColumnInfo info = new ColumnInfo<>(id, type);
return get(info);
}
/**
* Retrieve a column of data from the data frame using the provided column information.
* @param info the column information to use to retrieve the data.
* @param the type of the data in the array.
* @return the data in the ith column as an array of the given type.
*/
public T[] get(final ColumnInfo info) {
return info.clazz.cast(columnMap.get(info));
}
// @Override
// public String toString() {
// StringBuilder sb = new StringBuilder();
// final int nrows = (data.size() > 0)? data.get(0).size() : 0;
// final int fixedWidth = 15;
// Column columnData;
// String s;
// for (int i = 0; i < data.size(); i++) {
// s = "Type:" + data.get(i).getSimpleTypeName();
// sb.append(String.format("%-" + fixedWidth + "." + fixedWidth + "s", s));
// sb.append("|");
// }
// sb.append("\n");
// for (int j = 0; j < nrows; j++) {
// for (int i = 0; i < data.size(); i++) {
// columnData = data.get(i);
// sb.append(String.format("%-" + fixedWidth + "." + fixedWidth + "s", columnData.get(j)));
// sb.append("|");
// }
// if (j != nrows - 1) {
// sb.append("\n");
// }
// }
// return sb.toString();
// }
/**
* Print the string representation of this dataframe to the console.
*/
public void print() {
System.out.println(toString());
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
DataFrame dataFrame = (DataFrame) o;
if (!columnIdMap.equals(dataFrame.columnIdMap)) return false;
return columnMap.equals(dataFrame.columnMap);
}
@Override
public int hashCode() {
int result = columnIdMap.hashCode();
result = 31 * result + columnMap.hashCode();
return result;
}
public static class ColumnInfo {
private final String columnId;
private final Class clazz;
public ColumnInfo(final String columnId, final Class clazz) {
this.columnId = columnId;
this.clazz = clazz;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ColumnInfo that = (ColumnInfo) o;
if (!columnId.equals(that.columnId)) return false;
return clazz.equals(that.clazz);
}
@Override
public int hashCode() {
int result = columnId.hashCode();
result = 31 * result + clazz.hashCode();
return result;
}
}
}
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