# Half-Light Radii for Various Profiles

Written by Taro Sato on . Tagged: astro math

For a radial profile of $I(r)$, the enclosed flux within the radius $r$ is given by $F(r) = \int_{0}^{2 \pi} d\phi \int_{0}^{r} dr r I(r, \phi) \ .$ I’m only concerned about azimuthal symmetric cases, so $F(r) = 2\pi \int_{0}^{r} dr r I(r)$ . ... Continue reading.

# Testing if a Point is Inside a Polygon in Python

Written by Taro Sato on . Tagged: algorithm Python

Finally got around to find this out by Googling. It’s a useful function so I reproduce it here for copy & paste: def inside_polygon(x, y, points): """ Return True if a coordinate (x, y) is inside a polygon defined by the list of verticies [(x1, y1), (x2, y2), . ... Continue reading.