I have written a program to
analyze the round Goki puzzle that I bought last
Wednesday. The program can be used to generate an
Exact Cover, to compress the resulting solutions and has some options to
analyze the results. There are but a limited number of ways the pieces around
the central round piece can be placed not taking into account rotations and
mirroring. If we furthermore ignore the colouring of the pieces, but only look
to the layout, there are 1,789,051 unique solutions. This is much more than I
had expected when I bought the puzzle. To structure the solutions, one can look
at the number of possible outer contours when adding pieces from the center. I
have sorted the pieces from the center to the outside, first by the first
circular layer they occur in, next on the number of circular layers they
cover, and next on the number of radial sectors they cover. Below the list of
number of countours by selected number of pieces (where all pieces with the
same shape but a different colour are counted as one): 1, 2, 5, 5, 28, 13, 13,
26, 12, 30, 55, 55, 588, 1202, 402, 236, 20, 4, 1, and 1 (obviously). I also
looked at the correlation between the positions of inner and outer pieces
with respect their occurences in the solutions, and it seems there are no
strong correlations.
Conny and I made a biking trip of about 32Km
along some marke stones on the South and West
borders of the Enschede township. These are the marke stones/poles we visited:
At 10:50, the Leppinkpaal
At 11:00, the Kattenstaartpaal
At 11:56, the Grevenpaal
At 12:52, the Hogeveldpaal
At 13:11, the Belderspaal
At 14:07, the Zandboerpaal
We searched for the Fabelhuttesteen, but did not find it, not knowing the
exact location. At home we discovered that we must af approached it within
less than 10 meters.
I paid a visit to TkkrLab for the first time
in a long time. There were about nine people present. We did have a metameet. I
spend some time programming. I also reorganized my box at the space. I had
forgotten it contained the motherboard of my first PC. I donated three SCSI harddisk of 36Gbyte to another member,
who wanted to something with harddisk platters.
I continued working on the program for the Round
Goki puzzle. I did some refactoring and introduced an iterator, with some goto
statements, which looks rather strange until you understand how it works. It
implements a recursive function where an array is used to store the variables
on the stack. The label l_call indicates the starting point of a
(recursive) call and the label l_return gives the location where the
call should return. I added some functions to calculate for each combinations
of two (type of) pieces the possible combinations do occur in a solution.
Below a table is given of the percentages of combinations that do not occur in
a solution, where zero is replaced by a dash for clarity. A dash thus means
that one can place the two (type of) pieces freely on their possible locations
(not overlapping each other) and always can find a solution to the puzzle. The
colomn marked with a hash, gives the number of ways to place the (type of)
piece, which is higher if there is more than one piece of given type.
# A B C D E F G H I J K L M N O P Q R
A 2
B 12 -
C 66 - 95
D 54 88 56 91
E 12 75 - 78 67
F 12 59 - 75 75 13
G 12 13 - 64 39 - -
H 12 21 - 63 47 - - -
I 12 - - 64 30 - - - -
J 12 - - 64 30 - - - - -
K 12 - - 64 30 - - - - - -
L 54 - 12 79 43 6 3 - 1 - - -
M 220 - 28 84 54 17 12 4 7 - 22 - 1
N 66 - 16 78 44 10 7 2 3 - - - - 17
O 12 - - 64 23 - - - - - - - 52 4 -
P 220 24 48 89 66 38 38 31 36 85 29 30 92 44 44 42
Q 12 - - 64 23 - - - - 9 - - - 34 - - 30
R 12 - - 64 23 - - - - - - - - 10 - - 42 -
S 12 - - 64 23 - - - - - - - 6 24 - - 22 - -
Conny and I made a trip to the Ammerter
Gräberfeld nature reserve in Germany in the hope to find some more
information about the archaeological findings in the area. The area is along
the Flamingo biking route which is on both sides of the border between the
Netherlands and Germany. We had seen it on one of the maps along the route.
We walked along the biking route along the area but did not find any
information signs.
We had a record of eight tropical days in a row,
where a tropical day is defined as a day with temperatures above 30°
Celsius. This broke the previous record of six days. The minimum and maximum
temperatures of the past days at Twenthe Airport weather station are:
min. max.
August 6 14.1 31.7
August 7 14.4 34.2
August 8 14.4 34.6
August 9 18.5 32.2
August 10 15.3 32.9
August 11 19.7 34.6
August 12 18.7 33.3
August 13 18.6 32.0
Around 20:15 it started to rain with some thunder and lightning. The
prediction for maximum temperature is 26.8° Celsius and stay around that
level for the coming days.
I went to Concordia to see the exhibitions. I did not have to register on
forehand like a few months ago. I saw the
exhitionOne / Een with works from twelve artist from the region. I took one of
the information leaflets and did not immediately realize that it was the
Tweants dialect
version. Due to the heat and the high humidity, I could not really concentrate
and I only very causally walked through the exhibition. I liked the works
by:
The heat wave (according to the definition used in the Netherlands) that started on August 5 has
ended today, with yesterday being the ninth tropical day with temperatures
above 30° Celsius. Last Friday the temperature reached 29.9° Celsius
at the weather station at (the former) Airport Twenthe.
This evening, I got an Anet A6 Prusa i3 3D printer from a member of TkkrLab. I want to see if I can get it running with some slicer software
and also think about writing programs that generate G-code for it. I found the specification of the Prusa-specific G-codes.
Peter Struycken invited Conny and I for a visit to Museum MORE. I had never heard of this museum before. There were three
exhibitions. The first exhibition was a
selection of works from the collection of the museum. I found the followings
works notable:
Zomergasten
("Summer Residents") is a program on Dutch television which takes up an
entire Sunday evening, lasting typically three hours, in which a notable guest
is being interviewed interspersed with (usually ten) cinema or television
footage selected by the guest. Earlier this summer, Conny asked what would be
my ten selections for fragments that I would use if I would have been asked to
appear in the program. Here is my list of ten (actually eleven) fragments:
At 14:12, I bought the book AKI eindexamen catalogus 2001: wat is de
filosofie achter je werk? written by Boris Veldhuijzen van Zanten, Nelleke
Zandwijk, Sipke Huisman, and Maarten Binnendijk in Dutch and English and
published by AKI in 2001,
ISBN:9789075522181, from Kringloop Enschede for
€ 1.00.
I have implemented an algorithm using
JavaScript to generate a random PARR configuration, which consists of a number of dots on a four by five
grid connected with a number of lines. The number of dots and lines can be
specified. For pratical reasons the number of dots is limited to a maximum
eleven. I took care that every possible configuration has the same change of
being shown. This algorithm generates all
possible configurations without any restrictions, which means with crossing
diagonals and not all dots connected.
