In this recipe, we will use the diagrams package to draw a path from driving directions. We simply categorize all possible travel headings into eight cardinal directions with an associated distance. We use directions provided by Google Maps in the following screenshot and reconstruct the directions from a text file:
Install the diagrams library as follows:
$ cabal install diagrams
Create a text file called input.txt that contains one of the eight cardinal directions followed by the distance, with each step separated by a new line:
$ cat input.txt N 0.2 W 0.1 S 0.6 W 0.05 S 0.3 SW 0.1 SW 0.2 SW 0.3 S 0.3
Import the relevant libraries as follows:
{-# LANGUAGE NoMonomorphismRestriction #-} import Diagrams.Prelude import Diagrams.Backend.SVG.CmdLine (mainWith, B)Draw a line-connected path from a list of vectors as follows:
drawPath :: [(Double, Double)] -> Diagram B R2 drawPath vectors = fromOffsets . map r2 $ vectors
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