Binary file to ROOT file

ROOT
1

Hello Everyone,

I have a binary file and I want to convert it into .root format, can anyone help me how to do?
The reason is because I am dealing with large amount of data for the analysis.

for example:
The attached file is binary file contain a single variable of 2bytes(16bits) and it runs for 500 events and each event contain 1024 entries.

Thanks in advance.

mia
test500ped.dat (1000 KB)

2

[code]//
// test500ped.cxx
//
// Usage:
// root [0] .x test500ped.cxx
// root [1] TFile *f = TFile::Open(“test500ped.root”, “read”);
// root [2] f->ls();
// root [3] tree->Print();
// root [4] tree->Draw(“ped”);
// root [5] tree->Draw(“ped[0]”);
// root [6] tree->Draw(“ped[1]”);
// root [7] tree->Draw(“ped[1023]”);
//

#include “TFile.h”
#include “TTree.h”

#include

void test500ped(void) {
UShort_t ped[1024]; // an array of 16 bit unsigned integers
FILE *fin = fopen(“test500ped.dat”, “r”);
if (!fin) {
printf(“Error : test500ped.dat not found!\n”);
return;
}
TFile *fout = TFile::Open(“test500ped.root”, “recreate”);
TTree tree = new TTree(“tree”, “A TTree from test500ped.dat”);
// “==> Case A” in http://root.cern.ch/root/html/TTree.html
tree->Branch(“ped”, ped, “ped[1024]/s”); // “/s” = "UShort_t"
while ( sizeof(ped) == fread(ped, 1, sizeof(ped), fin) ) {
#if 0 / 0 or 1 */
// swap the high and low bytes (endianness correction)
for (Int_t i = 0; i < ((Int_t)sizeof(ped)); i += 2) {
UChar_t c = *((UChar_t *)ped + i);
*((UChar_t *)ped + i) = *((UChar_t *)ped + i + 1);
*((UChar_t )ped + i + 1) = c;
}
#endif / 0 or 1 */
tree->Fill();
}
fclose(fin); // no longer needed
tree->Write();
delete fout; // automatically deletes the “tree”, too
return;
}[/code]

3

Thanks alot, its working.