# <div align="center"><strong>torch-scatter-2.0.9</strong></div>
## 简介
torch-scatter是一个在PyTorch库中使用的Python库，它用于从张量中随机选择元素并返回一个新的张量。这个库提供了一种简单的方法来创建具有随机标签的数据集，这对于许多机器学习任务非常有用，例如数据增强或生成对抗网络(GANs)。

## 依赖安装
+ pytorch1.10或者pytorch1.13 以及对应的torchvision（建议dtk-22.04.2、dtk-23.04与dtk-23.10）
+ python 3.7-3.10

### 1、使用源码编译方式安装

#### 编译环境准备
提供2种环境准备方式：

1. 基于光源pytorch基础镜像环境：镜像下载地址：[https://sourcefind.cn/#/image/dcu/pytorch](https://sourcefind.cn/#/image/dcu/pytorch)，根据pytorch、python、dtk及系统下载对应的镜像版本。

2. 基于现有python环境：安装pytorch和torchvision，whl包下载目录：[https://cancon.hpccube.com:65024/4/main/pytorch](https://cancon.hpccube.com:65024/4/main/pytorch)，[https://cancon.hpccube.com:65024/4/main/vision](https://cancon.hpccube.com:65024/4/main/vision)，根据python、dtk版本,下载对应pytorch和torchvision的whl包。安装命令如下：
```shell
pip install torch* (下载的torch的whl包)
pip install torchvision* (下载的torchvision的whl包)
pip install setuptools==59.5.0 wheel
```

#### 源码编译安装
- 代码下载
```shell
git clone http://developer.hpccube.com/codes/aicomponent/torch-scatter # 根据编译需要切换分支
```
- 源码编译（进入torch-scatter目录）：
```
export C_INCLUDE_PATH=/public/software/apps/DeepLearning/PyTorch_Lib/gflags-2.1.2-build/include:$C_INCLUDE_PATH
export CPLUS_INCLUDE_PATH=/public/software/apps/DeepLearning/PyTorch_Lib/gflags-2.1.2-build/include:$CPLUS_INCLUDE_PATH
export C_INCLUDE_PATH=/public/software/apps/DeepLearning/PyTorch_Lib/glog-build/include:$C_INCLUDE_PATH
export CPLUS_INCLUDE_PATH=/public/software/apps/DeepLearning/PyTorch_Lib/glog-build/include:$CPLUS_INCLUDE_PATH
export C_INCLUDE_PATH=$ROCM_PATH/rocrand/include:$C_INCLUDE_PATH
export CPLUS_INCLUDE_PATH=$ROCM_PATH/rocrand/include:$CPLUS_INCLUDE_PATH
export LD_LIBRARY_PATH=$ROCM_PATH/rocrand/lib:$LD_LIBRARY_PATH
export FORCE_ONLY_HIP=1
export CC=hipcc
export CXX=hipcc

python setup.py install
```
#### 注意事项
+ 若使用pip install下载安装过慢，可添加pypi清华源：-i https://pypi.tuna.tsinghua.edu.cn/simple/
+ ROCM_PATH为dtk的路径，默认为/opt/dtk

## 验证

```python
import torch
from torch_scatter import scatter_max

src = torch.tensor([[2, 0, 1, 4, 3], [0, 2, 1, 3, 4]])
index = torch.tensor([[4, 5, 4, 2, 3], [0, 0, 2, 2, 1]])

out, argmax = scatter_max(src, index, dim=-1)
```

```
print(out)
tensor([[0, 0, 4, 3, 2, 0],
        [2, 4, 3, 0, 0, 0]])

print(argmax)
tensor([[5, 5, 3, 4, 0, 1]
        [1, 4, 3, 5, 5, 5]])
```

## Known Issue
- 该库没有基于cpu环境修改，仅支持dcu，请在有dcu卡的环境运行。
- 如需完整使用所有pyg功能，请pip install torch-geometric

## 参考资料
- [README_ORIGIN](README_ORIGIN.md)
- [https://pypi.org/project/torch-scatter/2.0.9/](https://pypi.org/project/torch-scatter/2.0.9/)