Re: 2D scatter plot with a color map

From: <mat_at_ihep.ac.cn>
Date: Fri, 9 Mar 2012 15:23:02 +0800


Hi, you can use
  g1->Draw("COLZ");
instead of g1->Draw("scat4z");
And it works.

Best regards

Martin

ÔÚ2012-03-09 14:37:31,<mat_at_ihep.ac.cn>дµÀ£º
> Dear All,
>
> I want to make a 2D scatter plot with a color map. I'm using TGraph2D and don't know the option of getting the color map working.
>
> I would appreciate if someone can show me how.
>
> The example macro I'm using is the following,
>
> void ScatPlotGauss(){
> Int_t i = 0, j = 0, k = 0, n = 0;
> Double_t ux = 0., uy = 0.;
> Double_t Sx = 2., Sy = 2.;
> const Int_t MAXP = 10;
> Double_t a[MAXP+1], b[MAXP+1];
> Double_t X[(MAXP+1)*(MAXP+1)], Y[(MAXP+1)*(MAXP+1)], Z[(MAXP+1)*(MAXP+1)];
>
> gStyle->SetPalette(1);
>
> for (Int_t i = 0; i <= MAXP; i++){
> a[i] = i - MAXP/2.;
> for (Int_t j = 0; j <= MAXP; j++){
> b[j] = j - MAXP/2.;
> X[k] = a[i];
> Y[k] = b[j];
> Z[k] = TMath::Exp(-((a[i]-ux)*(a[i]-ux)/(2.*Sx*Sx) + (b[j]-uy)*(b[j]-uy)/(2.*Sy*Sy)));
> k++;
> }
> }
>
> n = k;
>
> TCanvas* c1 = new TCanvas("Scat","Scat",10,10,500,500);
>
> TGraph2D *g1 = new TGraph2D(n, X, Y, Z);
> g1->Draw("scat4z");
>
> g1->GetYaxis()->SetTitle("Y");
> g1->GetXaxis()->SetTitle("X");
>
> }
>
Received on Fri Mar 09 2012 - 08:23:18 CET

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