Hi everyone.

Is it possible to add a specific point to a 3d plot so its clearly visible like this example (done with python) ?

I’d like to add the minimum found by a gradient descent algorithm for a function and make it clearly visible on the plot. Here’s my code :

```
int main() {
std::vector<double> initialGuess = {3,4};
std::vector <double> min = gradientDescent(initialGuess, exampleFunction);
// Create a 3D graph
TGraph2D *graph = new TGraph2D();
TGraph2D *graph2 = new TGraph2D();
// Fill the graph with points from the function
for (double x = -2; x <= 2; x += 0.1) {
for (double y = -2; y <= 2; y += 0.1) {
double z = exampleFunction({x, y});
graph->SetPoint(graph->GetN(), x, y, z);
}
}
// Add the minimum point to the graph
graph2->SetPoint(0, min[0], min[1], min[2]);
graph2->SetMarkerColor(kRed);
graph2->SetMarkerStyle(20);
// Create a canvas to display the 3D plot
TCanvas *canvas = new TCanvas("canvas", "3D Plot", 800, 600);
graph2->Draw("p");
graph->Draw("surf1");
return 0;
}
```

Thanks in advance

Lukas.

*ROOT Version:* 6.30/04