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*ROOT Version:* 6.24/06

*Platform:* Mac Apple M1

*Compiler:* XCODE 12

I wanted to ask for a information.

I am studying ROOT.

I have 100 files and each file has 9 columns.

I need to take the x data of the first column and for every other y the relative values.

using the push_back method i create the vectors X and Y[8].

Now to normalize it, I need to take the smallest value among the elements of X and translate all the points and make a graph with all the points translated.

I wanted to ask where I am going wrong.

M= 8 columns

I = 100 file with 9 columns-- 1 for X and 8 for Y — for (int i=0; i<N; i++){ etc…

```
int npoints = (int)X.size();
for (int k=0; k<M; k++) {
g[i][k]= new TGraph();
g[i][k]->SetNameTitle( Form("graphic_name_%d_%d",i,k), Form("graphic_name_ %d_%d",i,k) );
}
for (int p=0; p<M; p++) {
for( int b=0; b<npoints; b++){
float a=X[0];
double t;
t=b-a;
g[i][p]->SetPoint(b,X[t],Y[p][t]);
}
}
```

please,can you help me?

thanks