Math::...Tiling(3pm)

πŸ“¦
version 129 Β· 3 versions
, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

🌸 Math::...Tiling 🌸

okay bestie, so the full name of this page is Math::...Tiling(3pm) β€” it's the User Contributed Perl Documentation and it lives in Math::PlanePath::LTiling πŸ’–


✨ NAME ✨

Math::PlanePath::LTiling β€” a 2x2 self-similar tiling made of four pattern parts πŸ’…


πŸ¦‹ SYNOPSIS πŸ¦‹

use Math::PlanePath::LTiling;
my $path = Math::PlanePath::LTiling->new;
my ($x, $y) = $path->n_to_xy (123);

πŸ‘‘ DESCRIPTION πŸ‘‘

So this is a self-similar tiling made out of "L" shapes, and it's genuinely so cute. You take a base "L", then replicate it four times with the end parts turned +90 and -90 degrees to make a bigger L. Like this:

                                               +-----+-----+
                                               |12   |   15|
                                               |  +--+--+  |
                                               |  |14   |  |
                                               +--+  +--+--+
                                               |  |  |11   |
                                               |  +--+  +--+
                                               |13   |  |  |
                          +-----+              +-----+--+  +--+--+-----+
                          | 3   |              | 3   |  |10   |  |    5|
                          |  +--+        -->   |  +--+  +--+--+  +--+  |
                          |  |  |              |  |  | 8   |   9 |  |  |
           +--+           +--+  +--+--+        +--+  +--+--+--+--+  +--+
           |  |     -->   |  | 2   |  |        |  | 2   |  |  |   6 |  |
           |  +--+        |  +--+--+  |        |  +--+--+  |  +--+--+  |
           | 0   |        | 0   |   1 |        | 0   |   1 | 7   |   4 |
           +-----+        +-----+-----+        +-----+-----+-----+-----+

The parts get numbered left, then middle, then upper. And that relative numbering stays put when it gets rotated at the next replication level β€” think N=4 to N=7, no cap.

What you end up with is 1 of every 3 points in the first quadrant, with this subtle little layout of points and spaces that makes diagonal lines and teeny 2x2 blocks. Obsessed honestly:

           15  |  48          51  61          60 140         143 163
           14  |      50                  62         142                 168
           13  |          56          59                 139         162
           12  |  49          58              63 141             160
           11  |  55              44          47 131         138
           10  |          57          46                 136         137
            9  |      54                  43         130                 134
            8  |  52          53  45             128         129 135
            7  |  12          15  35          42              37  21
            6  |      14                  40          41                  22
            5  |          11          34                  38          25
            4  |  13              32          33  39          36
            3  |   3          10               5  31              26
            2  |           8           9                  27          24
            1  |       2                   6          30                  18
           Y=0 |   0           1   7           4  28          29  19
               +------------------------------------------------------------
                 X=0   1   2   3   4   5   6   7   8   9  10  11  12  13  14

On the X=Y leading diagonal, N=0,2,8,10,32,etc β€” those are the integers made from only digits 0 and 2 in base 4. Or, same energy, the integers which have zero bits at all even numbered positions, binary c0d0e0f0 ⭐


🌈 Left or Upper 🌈

Option L_fill => "left" or L_fill => "upper" numbers the tiles at their left end or upper end respectively. Slay, let's look:

           L_fill => 'left'           8  |      52              45  43
                                      7  |          15                      42
           +-----+                    6  |  12              35          40
           |     |                    5  |      14                  34  33
           |  +--+                    4  |      13  11          32
           | 3|  |                    3  |                  10   9   5
           +--+  +--+--+              2  |   3           8           6      31
           |  |    2| 1|              1  |           2   1               4
           |  +--+--+  |             Y=0 |       0               7
           |    0|     |                 +------------------------------------
           +-----+-----+                   X=0   1   2   3   4   5   6   7   8

           L_fill => 'upper'          8  |          53                  42
                                      7  |      12              35  40
           +-----+                    6  |          14  15      34          41
           |    3|                    5  |  13          11  32              39
           |  +--+                    4  |              10          33
           |  | 2|                    3  |       3   8
           +--+  +--+--+              2  |       2           9           5
           | 0|     |  |              1  |   0               7   6          28
           |  +--+--+  |             Y=0 |           1               4
           |     | 1   |                 +------------------------------------
           +-----+-----+                   X=0   1   2   3   4   5   6   7   8

The vibe of this is to disrupt the pattern a little bit, though the overall structure of the replications is unchanged β€” it's giving chaotic but structurally sound.

And just so you know: "left" is as viewed looking towards the L from above. ngl it may have been better to call it "right", but that's not changing now πŸ™ˆ


πŸŽ€ Ends πŸŽ€

Option L_fill => "ends" numbers the two endpoints within each "L", first the left then upper. This is literally the inverse of the default middle shown above, ie. it visits all the points which the middle option doesn't β€” so that's 2 of every 3 points in the first quadrant πŸ’–

           +-----+
           |    7|
           |  +--+
           | 6| 5|
           +--+  +--+--+
           | 1|    4| 2|
           |  +--+--+  |
           |    0| 3   |
           +-----+-----+

            15  |      97 102         123 120         281 286         327 337
            14  |  96     101 103 122 124     121 280     285 287 326 325
            13  |  99 100     113 118     125 126 283 284     279 321     324
            12  |      98 112     117 119 127         282 278 277     320 323
            11  |     111 115 116      89  94         263 273     276 274 266
            10  | 110 109     114  88      93  95 262 261     272 275     268
             9  | 105     108 106  91  92      87 257     260 258 271 269
             8  |     104 107          90  86  85     256 259         270 265
             7  |      25  30          71  81      84  82  74          43  40
             6  |  24      29  31  70  69      80  83      76  75  42  44
             5  |  27  28      23  65      68  66  79  77      72  50      45
             4  |      26  22  21      64  67          78  73      52  51  47
             3  |       7  17      20  18  10          63  55  53      48  34
             2  |   6   5      16  19      12  11  62  61      54  49      36
             1  |   1       4   2  15  13       8  57      60  58  39  37
            Y=0 |       0   3          14   9          56  59          38  33
                +------------------------------------------------------------
                  X=0   1   2   3   4   5   6   7   8   9  10  11  12  13  14

πŸ’… All πŸ’…

Option L_fill => "all" numbers all three points of each "L" β€” middle, left then right, in that order. With this one the path visits all points of the first quadrant, periodt πŸ”₯

                                  7  |  36  38  46  45 105 107 122 126
           +-----+                6  |  37  42  44  47 106 104 120 121
           | 9 11|                5  |  41  43  33  35  98 102 103 100
           |  +--+                4  |  39  40  34  32  96  97 101  99
           |10| 8|                3  |   9  11  26  30  31  28  16  15
           +--+  +--+--+          2  |  10   8  24  25  29  27  19  17
           | 2| 6  7| 4|          1  |   2   6   7   4  23  20  18  13
           |  +--+--+  |         Y=0 |   0   1   5   3  21  22  14  12
           | 0  1| 5  3|             +--------------------------------
           +-----+-----+               X=0   1   2   3   4   5   6   7

Along the X=Y leading diagonal, N=0,6,24,30,96,etc β€” those are triples of the values from the single-point case, so 3* numbers using digits 0 and 2 in base 4, which is the same as 2* numbers using 0 and 3 in base 4. Iconic ✨


🫢 Level Ranges 🫢

For the "middles", "left" or "upper" cases with one N per tile, and taking the initial N=0 tile as level 0, a replication level is:

Nstart = 0
 to
Nlevel = 4^level - 1      inclusive

Xmax = Ymax = 2 * 2^level - 1

For example level 2, which is the large tiling shown in the introduction, is N=0 to N=4^2-1=15 and it extends to Xmax=Ymax=2*2^2-1=7. Cute math, honestly.

For the "ends" variation there's two points per tile, and for "all" there's three, in which case the Nlevel increases to:

Nlevel_ends = 2 * 4^level - 1
Nlevel_all  = 3 * 4^level - 1

⭐ FUNCTIONS ⭐

See "FUNCTIONS" in Math::PlanePath for behaviour common to all path classes. Bestie, that's the shared lore.

  • $path = Math::PlanePath::LTiling->new ()
  • $path = Math::PlanePath::LTiling->new (L_fill => $str) β€” Create and return a new path object. The L_fill choices are:
    "middle"    the default
    "left"
    "upper"
    "ends"
    "all"
  • ($x,$y) = $path->n_to_xy ($n) β€” Return the X,Y coordinates of point number $n on the path. Points begin at 0 and if "$n < 0" then the return is an empty list. No points for negative n, literally πŸ’€

🌸 Level Methods 🌸

  • ($n_lo, $n_hi) = $path->level_to_n_range($level) β€” Return:
    0,   4**$level - 1      middle, left, upper
    0, 2*4**$level - 1      ends
    0, 3*4**$level - 1      all

There are 4^level L shapes in a level, each containing 1, 2 or 3 points, numbered starting from 0. So many points, so much main character energy πŸ‘‘


πŸ¦‹ OEIS πŸ¦‹

Entries in Sloane's Online Encyclopedia of Integer Sequences related to this path include:

<http://oeis.org/A062880> (etc)

L_fill=middle
  A062880    N on X=Y diagonal, base 4 digits 0,2 only
  A048647    permutation N at transpose Y,X
               base4 digits 1<->3 and 0,2 unchanged
  A112539    X+Y+1 mod 2, parity inverted

L_fill=left or upper
  A112539    X+Y mod 2, parity

A112539 is a parity of bits at even positions in N, ie. count 1-bits at even bit positions (least significant is bit position 0), then add 1 and take mod 2. This works because in the pattern sub-blocks 0 and 2 are unchanged and 1 and 3 are turned so as to be on opposite X,Y odd/even parity, so a flip for every even position 1-bit. L_fill=middle starts on a 0 even parity, and L_fill=left and upper start on 1 odd parity. The latter is the form in A112539 and L_fill=middle is the bitwise 0<->1 inverse. iykyk πŸ’œ


πŸŽ€ SEE ALSO πŸŽ€

Math::PlanePath, Math::PlanePath::CornerReplicate, Math::PlanePath::SquareReplicate, Math::PlanePath::QuintetReplicate, Math::PlanePath::GosperReplicate


🌈 HOME PAGE 🌈

<http://user42.tuxfamily.org/math-planepath/index.html>

✨ LICENSE ✨

okay bestie, legal era πŸ’… but fr it matters, so let's get into it.

Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Kevin Ryde

that's a whole decade of copyright years, we love a long-term commitment 🫢

This file is part of Math-PlanePath.

Math-PlanePath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. πŸ’–

Math-PlanePath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 😭 (yes it's yelling in caps, that's just how licenses talk, no cap)

You should have received a copy of the GNU General Public License along with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>. πŸ¦‹

ngl if you didn't get the license file, that link is your bestie. go get it. it's giving responsible open source citizen ✨

and that's the whole page, babe 🌸 you just read the entire Math::...Tiling(3pm) manpage, main character energy fr fr πŸ‘‘

this one came from the User Contributed Perl Documentation, it's perl v5.32.0, and the page was dated 2021-01-23 πŸŽ€

k bye, go tile something iconic πŸ’œπŸ§š