Code1161 — Week 13
Apply —
A big magic thing that pandas has, allows you to do things quickly.
Sort of like a map, applied to an axis in a dataframe.
Gives you back a series
Can add a new column
Pets[“do”] = Pets.apply(action, axis=1)
Will ad a new column to pets called “do””
Row.geometry.centroid will return a centroid of the polygon geometry, from shapely library
Returns a point
Burbs[“distance_from_unsw”] = burbs.geometry.distamce…
Will return a distance as a new column, Euclidian in latlongs(?), not kms
Geometry.convex_hull.plot()
Gets convex hulls
Geometry.envelope
Gets an envelope
Ways to check for an intersection:
- draw a circle — gives a radius, if distance is greater than the two intersections, can’t be intersecting
-maybe bounding box
- convex hull
(always work from the least computing to the most)
Row.centroid.cords
Returns centroid points as a (x, y) coord
Polygon inclusion test
Draw a vector across from point, if it intersects an even number of times -> out, even -> in
within() — also works
-good opportunity to use a lambda
chloropleth — colouring in a map
eg. plot(column=”fsdhf”, cmap=”spring”)