Can't get axis from a TGrap2D

ROOT
1

Hi,
I can’t get the Axis froma a TGraph2d, so I cannot set title or rang.
Here is my code

[code]#include “TCanvas.h”
#include “TROOT.h”
#include “TGraphErrors.h”
#include “TF1.h”
#include “Riostream.h”

void lab2 () {

gStyle->SetOptTitle(0); gStyle->SetOptStat(0); gStyle->SetPalette(1);

TGraph2D *g1 = new TGraph2D("1750_matrix.dat");

// g1->SetTitle(“Energy:TOF;Energy [channel];TOF [channel]”);

TCanvas *c1 = new TCanvas();	
g1->Draw("surf1");
g1->GetXaxis()->SetTitle("X");
g1->GetXaxis()->SetTitleOffset(1.5);
g1->GetYaxis()->SetTitleOffset(1.5);
g1->Draw("surf1");
c1->Update();

}[/code]

I can set the title with

// g1->SetTitle("Energy:TOF;Energy [channel];TOF [channel]");
But I can’t set TitleOffset.

Any solutions?

2 
g1->GetHistogram()->SetTitleOffset(0.1);