Vectors

Importing a Shapefile

Download sample Shapefile points_of_interest.zip and unzip it.

Import the file using v.in.ogr module. Note that you need to specify the full path to the file. 

v.in.ogr input=/path/to/points_of_interest.shp output=points_of_interest

Generating a hexagonal grid

To compute point density in a hexagonal grid for the vector map points_of_interest use the vector map itself to set extent of the computational region. The resolution is based on the desired size of hexagons. 
g.region vector=points_of_interest res=2000 -pa
Although computation region is usually not used in vector processing, the hexagonal grid is created as a vector map based on the previously selected extent and size of the grid. 
v.mkgrid map=hexagons -h

Computing statistics of points in polygons

The following counts the number of points per hexagon using the v.vect.stats module. 
v.vect.stats points=points_of_interest areas=hexagons count_column=count
The last command sets the vector map color table to viridis based on the count column. Use color table ryb if you have GRASS GIS 7.0. 
v.colors map=hexagons use=attr column=count color=viridis
Colored hexagons and modules used to create them

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