diff --git a/.gitignore b/.gitignore
index c795b054e5ade51b7031abab1581a5b7e2d2f5ba..b68c22374878336d26638cab74325ea1f8a49665 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-build
\ No newline at end of file
+build
+.vscode/*
\ No newline at end of file
diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index fa67db65a4e01f1df7d0fed706ca76b0419ab0cf..4a3ed5d1fc58f151be123195aa1b3da79524ab93 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -4,8 +4,8 @@
             "name": "Linux",
             "includePath": [
                 "${workspaceFolder}/**",
-                "/home/ming/root/include",
-                "/home/ming/root/lib"
+                "/home/mingf2/root/include",
+                "/home/mingf2/root/lib"
             ],
             "defines": [],
             "compilerPath": "/usr/bin/gcc",
diff --git a/Headers/draw.h b/Headers/draw.h
index f464978a27442fa921c82117b2ab9bf0c8895eb2..829290cf343335cb269a3684c85f408e3422ac37 100644
--- a/Headers/draw.h
+++ b/Headers/draw.h
@@ -3,14 +3,18 @@
 #include <iostream>
 
 #include "TCanvas.h"
+#include "TMath.h"
 #include "TH2F.h"
 #include "TGraph.h"
 #include "TStyle.h"
-#include "TEllipse.h"
+// #include "TEllipse.h"
+#include "TMarker.h"
 
 #include "../Headers/setup.h"
 
 int Backprojection(const Setup& config, const std::vector<Cone>& cones, 
                    std::vector<std::vector<double>>& image);
 
-int drawImage(const Setup& config, const std::vector<std::vector<double>>& image);
\ No newline at end of file
+int drawImage(const Setup& config, const std::vector<std::vector<double>>& image);
+
+int aitoff2xy(const double& l, const double& b, double &Al, double &Ab);
\ No newline at end of file
diff --git a/Headers/setup.h b/Headers/setup.h
index b8081a1c709c3d93d98485c4936c98c8548e959d..62fa497c651eb868e06805218a041498716e94c1 100644
--- a/Headers/setup.h
+++ b/Headers/setup.h
@@ -70,7 +70,7 @@ public:
     int pixelateSphere();
 
     // simulation setup
-    const int nCones= 1000;
+    const int nCones= 100;
     double trueTheta;
     double truePhi;
     Vector3D trueSource;
diff --git a/Sources/draw.cpp b/Sources/draw.cpp
index 97fe26577bfed9779f023e1373957dc5ff2b226d..4fd033b5c8baebaf1e85ea9da67972c8f731a203 100644
--- a/Sources/draw.cpp
+++ b/Sources/draw.cpp
@@ -124,13 +124,42 @@ int drawImage(const Setup& config, const std::vector<std::vector<double>>& image
     // // el1->Draw("SAME");
 
     // draw source 2
-    double sigma = 5;
-    TEllipse* el2 = new TEllipse(config.truePhi / conv, config.trueTheta / conv, sigma, sigma);
-    el2->SetFillColor(0);
-    el2->SetFillStyle(0);
-    el2->SetLineColor(4);
-    el2->Draw("SAME");
+    // double sigma = 5;
+    // TEllipse* el2 = new TEllipse(config.truePhi / conv, config.trueTheta / conv, sigma, sigma);
+    // el2->SetFillColor(0);
+    // el2->SetFillStyle(0);
+    // el2->SetLineColor(4);
+    // el2->Draw("SAME");
+
+    // draw source in aitoff 
+    double Ax, Ay;
+    aitoff2xy(config.truePhi / conv, config.trueTheta / conv, Ax, Ay);
+    TMarker *marker = new TMarker(Ax, Ay, 24);
+    // marker->SetMarkerColorAlpha(kBlue, 0.0);
+    marker->Draw("SAME");
+
     canvas->Draw();
 
     return 0;
+}
+
+int aitoff2xy(const double& l, const double& b, double &Al, double &Ab)
+{
+   Double_t x, y;
+
+   Double_t alpha2 = (l/2)*TMath::DegToRad();
+   Double_t delta  = b*TMath::DegToRad();
+   Double_t r2     = TMath::Sqrt(2.);
+   Double_t f      = 2*r2/TMath::Pi();
+   Double_t cdec   = TMath::Cos(delta);
+   Double_t denom  = TMath::Sqrt(1. + cdec*TMath::Cos(alpha2));
+   x      = cdec*TMath::Sin(alpha2)*2.*r2/denom;
+   y      = TMath::Sin(delta)*r2/denom;
+   x     *= TMath::RadToDeg()/f;
+   y     *= TMath::RadToDeg()/f;
+   //  x *= -1.; // for a skymap swap left<->right
+   Al = x;
+   Ab = y;
+
+   return 0;
 }
\ No newline at end of file
diff --git a/Sources/main.cpp b/Sources/main.cpp
index 34cde31d722f778ac1134faead365920912f3fe6..e0f3b8033b565ec086ef85164c3a1846d4e362b4 100644
--- a/Sources/main.cpp
+++ b/Sources/main.cpp
@@ -14,7 +14,8 @@ int main(int argc, char** argv) {
     const Setup config(10);
     // simulate some cones
     std::vector<Cone> cones;
-    std::srand(std::time(nullptr));
+    // std::srand(std::time(nullptr));
+    std::srand(0);
     // for (int i = 0; i < 10; i++)
     for (int i = 0; i < config.nCones; i++)
     {