I have an application where I have a numeric evolute that I want to
visualize. Essentially, I have a list of values within the evolute
that I want to display as a given literal character, while the
remaining values would be a default "background" literal character.
Everything works fine until I get to a point where I need to select
values in such a way that I retrieve not only the "anchor" (selected)
value from a list of ordered display characters but also one or more
(depending on how the ordered list is constructed) succeeding
separating characters. "From" seems to be the kind of thing I'd like
to do, but that returns only a single value for each element of the
lefthand argument. In other words, I know that you can do something
like:
0 4 10 18 { array
which will return FOUR elements from "array". However, since in my
case, each of the elements in "array" is followed (separated) by a
space character, what I *want* returned are four PAIRS of characters
(the element and its succeeding space): 0-1, 4-5, 10-11, and 18-19.
Is there some way to make "From" be able to do this, or can someone
suggest another approach? I'm stuck at the moment. Here's a sample
evolute of size 5:
13 14 15 16 17
12 3 4 5 18
11 2 1 6 19
10 9 8 7 20
25 24 23 22 21
For this example's sake, I decided to "mark" the Fibonacci series
(contained in a list):
f=. 1 2 3 5 8 13 21
After the earlier half of the program does its thing (correctly), the
next lines would be (e3 has 25 values):
e3=. 12 13 14 15 16 11 2 3 4 17 10 1 0 5 18 9 8 7 6 19 24 23 22 21
20
sqdata=. 'X @ @ . @ . . @ . . . . @ . . . . . . . @ . . . . '
e4=. (2 * e3) { sqdata NB. this is the problem area
e=. (2*5 , 5) $ e4
The end result (e) should look like this:
@ . . . .
. @ . @ .
. @ X . .
. . @ . .
. . . . @
The reason I need the spacing characters is because a square doesn't
look square on a screen or printer since characters are rectangular in
shape (not square). Looking square is important for my application.
Thanks in advance for any help solving this!
Harvey
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