Data-analysis

Decode
GUI
PKUXIADAQ
- Correlation
- Draw
GSIDAQ
Root
- Hitogram的bin太多会报错：
  - Error in TBufferFile::WriteByteCount: bytecount too large (more than 1073741822)
- TTree::Draw()：设置string的cut
  - tree->Draw("ye:yzid>>yze(60, 0, 60, 510, 0.0, 510.0)", "p==\"gamma\"");
- TTree::Draw()：数组下标 Iteration$
  - tree->Draw("data:Iteration$", "", "*", 1, 7)
- THttpServer::Register("Path", THD)
  - path（包括子path）不能以数字开头（不信你就试试！！）
- Error in TFile::WriteTObject: Directory ***.root is not writable
  - 这不是权限问题，是你文件close早了！！！
- TTree::Draw()：Get TGraph
```
n = tree->Draw("YSO0D.data:Iteration$>>tr", "", "", 167, 1);
TGraph *g = new TGraph(n,tree->GetV2(),tree->GetV1());
```