Multigraph problems

[faca87]

Hello, I’m doing a multigraph, but I get two errors

1. It draws the graph1, but it doesn’t the graph2

root [0] .x densities.cpp
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Info in <TCanvas::Print>: png file simulazione/densities.png has been created

2.Moreover, If I set the Logy it doesn’t print the axes

root [1] .x densities.cpp
Warning in <TCanvas::Constructor>: Deleting canvas with same name: c01
Error in <THistPainter::PaintInit>: log scale requested with a negative argument (-1.114438)
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Error in <THistPainter::PaintInit>: log scale requested with a negative argument (-1.114438)
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Error in <THistPainter::PaintInit>: log scale requested with a negative argument (-1.114438)
Error in <TGraphPainter::PaintGraph>: illegal number of points (0)
Info in <TCanvas::Print>: png file simulazione/densities.png has been created

Maybe the II error (the log) is related to the presence of some 0 values?? But in this case, shouldn’t it just neglet these values?

Here macro and data

densities.cpp (2.0 KB)
densities.txt (62.3 KB)

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ROOT Version: Not Provided
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[couet]

void densities() {
   const char *datain = "densities.txt";

   TCanvas *c01 = new TCanvas("c01","multigraph",1280,1024);
   auto mg = new TMultiGraph();
   float offx=1.3;
   float offy=1.3;
   float margr=0.08;
   float w=3;
   float margl=0.12;
   float line=2;
   gPad->SetLeftMargin(margl);
   gPad->SetRightMargin(margr);
   TGraph *graph1 = new TGraph(datain,"%lg %lg %*lg");
   TGraph *graph2 = new TGraph(datain,"%lg %*lg %lg");

printf("%d %d \n",graph1->GetN(),graph2->GetN() );

   graph1->SetMarkerColor(kBlue);
   graph1->SetLineColor(kBlue);
   graph1->SetMarkerStyle(3);
   graph1->SetMarkerSize(1.3);
   graph1->SetLineWidth(line);
   mg->Add(graph1);

   graph2->SetMarkerColor(kGreen);
   graph2->SetLineColor(kGreen);
   graph2->SetMarkerStyle(3);
   graph2->SetMarkerSize(1.3);
   graph2->SetLineWidth(line);
   mg->Add(graph2);

   mg->SetTitle("");
   mg->GetXaxis()->SetTitle("R (mm)");
   mg->GetYaxis()->SetTitle("Energy Density (J/cm^{3})");
   mg->GetYaxis()->SetTitleOffset(offy);
   mg->GetXaxis()->SetTitleOffset(offx);
   mg->GetYaxis()->SetTitleSize(40);
   mg->GetYaxis()->SetTitleFont(43);
   mg->GetYaxis()->SetLabelFont(43);
   mg->GetYaxis()->SetLabelSize(40);
   mg->GetXaxis()->SetTitleSize(40);
   mg->GetXaxis()->SetTitleFont(43);
   mg->GetXaxis()->SetLabelFont(43);
   mg->GetXaxis()->SetLabelSize(40);
   mg->Draw("ap");

///   graph1->GetXaxis()->SetNdivisions(10); //numero di punti * 2 (
   TLegend* leg = new TLegend(0.75, 0.75, .85, .85);
   leg->SetHeader("Legend");
   leg->SetNColumns(1);
   leg->AddEntry(graph1, "Target 1", "ap");
   leg->AddEntry(graph2, "Target 2", "ap");
   leg->Draw();

}

[faca87]

Thank you @couet, it works for the linear scale, but I still get the error for the log one…

is there a way to solve it too?

[couet]

The error message tells you the problem. You have negative values on Y:

root [1] Error in <THistPainter::PaintInit>: log scale requested with a negative argument (-1.117727)

[faca87]

Hello @couet , no…I don’t have negative numbers (you can see the data)…I’ve the 0, but I think it should neglets the 0

[couet]

void densities() {
   const char *datain = "densities.txt";

   TCanvas *c01 = new TCanvas("c01","multigraph",1280,1024);
   c01->SetLogy();

   auto mg = new TMultiGraph();
   float offx=1.3;
   float offy=1.3;
   float margr=0.08;
   float w=3;
   float margl=0.12;
   float line=2;
   gPad->SetLeftMargin(margl);
   gPad->SetRightMargin(margr);
   TGraph *graph1 = new TGraph(datain,"%lg %lg %*lg");
   TGraph *graph2 = new TGraph(datain,"%lg %*lg %lg");

   graph1->SetMarkerColor(kBlue);
   graph1->SetLineColor(kBlue);
   graph1->SetMarkerStyle(3);
   graph1->SetMarkerSize(1.3);
   graph1->SetLineWidth(line);
   mg->Add(graph1);

   graph2->SetMarkerColor(kGreen);
   graph2->SetLineColor(kGreen);
   graph2->SetMarkerStyle(3);
   graph2->SetMarkerSize(1.3);
   graph2->SetLineWidth(line);
   mg->Add(graph2);

   mg->SetTitle("");
   mg->GetXaxis()->SetTitle("R (mm)");
   mg->GetYaxis()->SetTitle("Energy Density (J/cm^{3})");
   mg->GetYaxis()->SetTitleOffset(offy);
   mg->GetXaxis()->SetTitleOffset(offx);
   mg->GetYaxis()->SetTitleSize(40);
   mg->GetYaxis()->SetTitleFont(43);
   mg->GetYaxis()->SetLabelFont(43);
   mg->GetYaxis()->SetLabelSize(40);
   mg->GetXaxis()->SetTitleSize(40);
   mg->GetXaxis()->SetTitleFont(43);
   mg->GetXaxis()->SetLabelFont(43);
   mg->GetXaxis()->SetLabelSize(40);
   mg->SetMinimum(0.0000001);
   mg->Draw("ap");

   TLegend* leg = new TLegend(0.75, 0.75, .85, .85);
   leg->SetHeader("Legend");
   leg->SetNColumns(1);
   leg->AddEntry(graph1, "Target 1", "ap");
   leg->AddEntry(graph2, "Target 2", "ap");
   leg->Draw();

}

[faca87]

Thank you @couet it works!