very simplistic implementation of spark in scheme
usage: load flare.scm in your favorite scheme implementation and call (spark '(list-of-numbers))
scheme@(guile-user)> (spark '(2 5 5.5 6 10))
$1 = (▂ ▄ ▅ ▅ █)
scheme@(guile-user)> (spark '(1 2 3 4 100 5 10 20 50 300))
$2 = (▁ ▁ ▁ ▁ ▃ ▁ ▁ ▁ ▂ █)
scheme@(guile-user)> (spark '(100 275 400 300))
$3 = (▂ ▆ █ ▆)
the formula for calculating the bars is as follows:
current number index
-------------- = --------------
maximum number length of list