xgboost

Classes | Namespaces
group_data.h File Reference

this file defines utils to group data by integer keys Input: given input sequence (key,value), (k1,v1), (k2,v2) Ouptupt: an array of values data = [v1,v2,v3 .. vn] and a group pointer ptr, data[ptr[k]:ptr[k+1]] contains values that corresponds to key k More...

`#include <cstddef>`
`#include <vector>`
`#include <algorithm>`
`#include <utility>`
`#include "xgboost/base.h"`
Include dependency graph for group_data.h:

Go to the source code of this file.

## Classes
class | xgboost::common::ParallelGroupBuilder< ValueType, SizeType, is_row_major >
| multi-thread version of group builder More...

## Namespaces
| xgboost
| namespace of xgboost
| xgboost::common

## Detailed Description

this file defines utils to group data by integer keys Input: given input sequence (key,value), (k1,v1), (k2,v2) Ouptupt: an array of values data = [v1,v2,v3 .. vn] and a group pointer ptr, data[ptr[k]:ptr[k+1]] contains values that corresponds to key k

Copyright 2014-2021 by Contributors

This can be used to construct CSR/CSC matrix from un-ordered input The major algorithm is a two pass linear scan algorithm that requires two pass scan over the data

Author
  Tianqi Chen