I am trying to compute the integral of a 2D dataset $f_r \, (\theta, \phi)$ where $\theta \in [0, \pi / 2[$ and $\phi \in [0, 2\pi]$. I am making the measurements myself, so I can choose the number of values and their coordinates.
My first idea was to use the different points to triangulate my definition set, and sum the mean value of the vertices of each triangle divided by their surface.
But my problem will appear when $\theta \rightarrow \pi/2$, because I cannot have any measurement for these values. Is there a good strategy to solve this problem ?