vectorize the function point_to_line() for time speed up

[sbrockhaus]

To speed up the computation of the idealized line by the function points_on_ideal(), I propose to vectorize the function point_to_line() such that the argument P0 expects a matrix of points and not just a single point.

A small benchmark on computation times shows that the time is reduced drastically. On my machine the mean computation time for an example with 1000 observations can be reduced from about 1400 to 100 microseconds.

As the functions points_on_ideal() and point_to_line() are both internal, it should be easy to replace point_to_line() by the vectorized version and keep everything else as is.

Attached you find such a vectorized version of point_to_line(), with some code for benchmarking (R-Code as .txt as .R files cannot be uploaded here).

Best,
Sarah

vectorize_point_to_line.txt

[sbrockhaus]

see pull request #3 for proposed changes on the package

[PascalKieslich]

Thanks, Sarah, for the suggestion, your implementation, and the benchmark! Just accepted the changes you proposed.