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High-performance Java Dataframe with integrated columnar storage (fork of tablesaw)
package org.datavec.dataframe.table;
import org.apache.commons.lang3.StringUtils;
import org.datavec.dataframe.api.*;
import org.datavec.dataframe.columns.Column;
import java.util.List;
/**
* A tabular data structure like a table in a relational database, but not formally implementing the relational algebra
*/
public interface Relation {
void addColumn(Column... cols);
void setName(String name);
default boolean isEmpty() {
return rowCount() == 0;
}
default String shape() {
return rowCount() + " rows X " + columnCount() + " cols";
}
default void removeColumn(int columnIndex) {
removeColumns(column(columnIndex));
}
/**
* Removes the given columns from the receiver
*/
void removeColumns(Column... columns);
default void removeColumns(String... columnName) {
Column[] cols = new Column[columnName.length];
for (int i = 0; i < columnName.length; i++) {
cols[i] = column(columnName[i]);
}
removeColumns(cols);
}
Table first(int nRows);
/**
* Returns the index of the column with the given columnName
*/
default int columnIndex(String columnName) {
int columnIndex = -1;
for (int i = 0; i < columnCount(); i++) {
if (columnNames().get(i).equalsIgnoreCase(columnName)) {
columnIndex = i;
break;
}
}
if (columnIndex == -1) {
throw new IllegalArgumentException(
String.format("Column %s is not present in table %s", columnName, name()));
}
return columnIndex;
}
/**
* Returns the column with the given columnName, ignoring case
*/
default Column column(String columnName) {
Column result = null;
for (Column column : columns()) {
if (column.name().equalsIgnoreCase(columnName)) {
result = column;
break;
}
}
if (result == null) {
throw new IllegalStateException(String.format("Column %s does not exist in table %s", columnName, name()));
}
return result;
}
/**
* Returns the column at columnIndex (0-based)
*
* @param columnIndex an integer at least 0 and less than number of columns in the relation
* @return the column at the given index
*/
Column column(int columnIndex);
/**
* Returns the number of columns in the relation
*/
int columnCount();
/**
* Returns the number of rows in the relation
*/
int rowCount();
/**
* Returns a list of all the columns in the relation
*/
List columns();
/**
* Returns the index of the given column
*/
int columnIndex(Column col);
/**
* Returns a String representing the value found at column index c and row index r
*/
String get(int c, int r);
/**
* Returns the name of this relation
*/
String name();
/**
* Clears all the dat in the relation, leaving the structure intact
*/
void clear();
List columnNames();
/**
* Returns an array of the column types of all columns in the relation, including duplicates as appropriate,
* and maintaining order
*/
default ColumnType[] columnTypes() {
ColumnType[] columnTypes = new ColumnType[columnCount()];
for (int i = 0; i < columnCount(); i++) {
columnTypes[i] = columns().get(i).type();
}
return columnTypes;
}
/**
* Returns an array of column widths for printing tables
*/
default int[] colWidths() {
int cols = columnCount();
int[] widths = new int[cols];
for (int i = 0; i < columnCount(); i++) {
widths[i] = columns().get(i).columnWidth();
}
return widths;
}
default String print() {
StringBuilder buf = new StringBuilder();
int[] colWidths = colWidths();
buf.append(name()).append('\n');
List names = this.columnNames();
for (int colNum = 0; colNum < columnCount(); colNum++) {
buf.append(StringUtils.rightPad(StringUtils.defaultString(String.valueOf(names.get(colNum))),
colWidths[colNum]));
buf.append(' ');
}
buf.append('\n');
for (int r = 0; r < rowCount(); r++) {
for (int c = 0; c < columnCount(); c++) {
String cell = StringUtils.rightPad(get(c, r), colWidths[c]);
buf.append(cell);
buf.append(' ');
}
buf.append('\n');
}
return buf.toString();
}
default Table structure() {
StringBuilder nameBuilder = new StringBuilder();
nameBuilder.append("Table: ").append(name()).append(" - ").append(rowCount()).append(" observations (rows) of ")
.append(columnCount()).append(" variables (cols)");
Table structure = Table.create(nameBuilder.toString());
structure.addColumn(IntColumn.create("Index"));
structure.addColumn(CategoryColumn.create("Column Name"));
structure.addColumn(CategoryColumn.create("Type"));
structure.addColumn(IntColumn.create("Unique Values"));
structure.addColumn(CategoryColumn.create("First"));
structure.addColumn(CategoryColumn.create("Last"));
for (Column column : columns()) {
structure.intColumn("Index").add(columnIndex(column));
structure.categoryColumn("Column Name").add(column.name());
structure.categoryColumn("Type").add(column.type().name());
structure.intColumn("Unique Values").add(column.countUnique());
structure.categoryColumn("First").add(column.first());
structure.categoryColumn("Last").add(column.getString(column.size() - 1));
}
return structure;
}
default String summary() {
StringBuilder builder = new StringBuilder();
builder.append("\n").append("Table summary for: ").append(name()).append("\n");
for (Column column : columns()) {
builder.append(column.summary().print());
builder.append("\n");
}
builder.append("\n");
return builder.toString();
}
default BooleanColumn booleanColumn(int columnIndex) {
return (BooleanColumn) column(columnIndex);
}
default BooleanColumn booleanColumn(String columnName) {
return (BooleanColumn) column(columnName);
}
default NumericColumn numericColumn(int columnIndex) {
Column c = column(columnIndex);
if (c.type() == ColumnType.CATEGORY) {
CategoryColumn categoryColumn = (CategoryColumn) c;
return categoryColumn.toIntColumn();
} else if (c.type() == ColumnType.BOOLEAN) {
BooleanColumn booleanColumn = (BooleanColumn) c;
return booleanColumn.toIntColumn();
}
return (NumericColumn) column(columnIndex);
}
default NumericColumn numericColumn(String columnName) {
Column c = column(columnName);
if (c.type() == ColumnType.CATEGORY) {
CategoryColumn categoryColumn = (CategoryColumn) c;
return categoryColumn.toIntColumn();
} else if (c.type() == ColumnType.BOOLEAN) {
BooleanColumn booleanColumn = (BooleanColumn) c;
return booleanColumn.toIntColumn();
}
return (NumericColumn) column(columnName);
}
/**
* Returns the column with the given name cast to a NumericColumn
*
* Shorthand for numericColumn()
*/
default NumericColumn nCol(String columnName) {
return numericColumn(columnName);
}
/**
* Returns the column with the given name cast to a NumericColumn
*
* Shorthand for numericColumn()
*/
default NumericColumn nCol(int columnIndex) {
return numericColumn(columnIndex);
}
default FloatColumn floatColumn(int columnIndex) {
return (FloatColumn) column(columnIndex);
}
default FloatColumn floatColumn(String columnName) {
return (FloatColumn) column(columnName);
}
default IntColumn intColumn(String columnName) {
return (IntColumn) column(columnName);
}
default IntColumn intColumn(int columnIndex) {
return (IntColumn) column(columnIndex);
}
default ShortColumn shortColumn(String columnName) {
return (ShortColumn) column(columnName);
}
default ShortColumn shortColumn(int columnIndex) {
return (ShortColumn) column(columnIndex);
}
default LongColumn longColumn(String columnName) {
return (LongColumn) column(columnName);
}
default LongColumn longColumn(int columnIndex) {
return (LongColumn) column(columnIndex);
}
default DateColumn dateColumn(int columnIndex) {
return (DateColumn) column(columnIndex);
}
default DateColumn dateColumn(String columnName) {
return (DateColumn) column(columnName);
}
default TimeColumn timeColumn(String columnName) {
return (TimeColumn) column(columnName);
}
default TimeColumn timeColumn(int columnIndex) {
return (TimeColumn) column(columnIndex);
}
default CategoryColumn categoryColumn(String columnName) {
return (CategoryColumn) column(columnName);
}
default CategoryColumn categoryColumn(int columnIndex) {
return (CategoryColumn) column(columnIndex);
}
default DateTimeColumn dateTimeColumn(int columnIndex) {
return (DateTimeColumn) column(columnIndex);
}
default DateTimeColumn dateTimeColumn(String columnName) {
return (DateTimeColumn) column(columnName);
}
}