Why isn't the result 0 0 0 0 0 1 0 0 ?
A=:'^<v>'
B=:'<V>^'
f=: 13 :'((|.|:|.4|+/~i.4),4|+/~i.4){y'
f A
v<^>
<^>v
^>v<
>v<^
^<v>
<v>^
v>^<
>^<v
B-:"1 f A
0 0 0 0 0 0 0 0
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of David Lambert
Sent: Thursday, December 3, 2015 9:40 AM
To: programming <[email protected]>
Subject: [Jprogramming] adventofcode day 3
Say P is a rank 2 list of 2D coordinates
4{.P
0 0
0 1
0 2
_1 2
Let's map the flight.
NB. shift moves origin making minimum coordinates independently 0 NB. use:
shift COORDINATES
shift=: -"1 <./
NB. grid generates an array of zeros large enough for only the positive
coords NB. use: grid COORDS
grid=: 0 $~ >:@:(>./)
NB. COORDS draw GRID NB. color by number
draw=: (i.@#@[)`(;/@:[)`]}
load'viewmat'
flight =: viewmat @: (draw grid) @: shift
flight P
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