I finished reading the novel De Godenmakers
(the Dutch translation of The Godmakers) by Frank Herbert, which I started reading on January 18, the day I bought the book. Today, I found out that the book
first appeared as four stories in Astounding Science Fiction, namely:
The priests of psi, appeared in Astounding, February 1960.
When I was reading the book, I already had the idea that the book was compiled
from a number of stories. I knew that Dune
was also serialized first. I compared the first story with the book and noticed
that two chapters were added to the book. Maybe some more material has been
added to the book to glue the stories together or small edits to harmonize
them. Besides the Dune series, I have not read many other books by Herbert. I
found this book quite interesting and even started to read it again, because it
is the kind of book that requires a second reading because things mentioned in
the first part of the book only make sense when you have finished reading the
whole book.
Yesterday, I had a look at the DLX1 CWEB file by Donald E. Knuth for solving Exact Cover
problems. The CWEB file is a type of literate programming from which both a document and
a C program can be generated. I cloned ascherer/cweb and compiled it with make. I used the CTANGLE
program to produce the dlx1.c program and the CWEAVE program to
produce the dlx1.texTeX file. I tried to produce a PDF document from this, but got some
error message. I have not investigated what kind of environment you need to
prevent these error messages. I did look a little bit at the C program. In my
program for solving Exact Cover problems each 'node' has six pointers. The DLX1
program only has three of them in the form of indices in an array and an
int field called spare. Thinking about it this afternoon,
I guessed that the nodes of a row (which he calls an option) have succesive
indices and that some calculation is used to determine the first and last of
the nodes that are part of a row. Now reading the source file, I read in the Section 'Data structures' that he is using
spacer nodes. The spare field is not used in all nodes. There are
really a lot of options on how to implement all the different operations. I
am still thinking how I am going to proceed to solve the Fancy Tetris Wooden
Puzzle.
I went to B93 to see the exibition: On Parasitic
Infrastructure and Speculations on the Monumentality of Ruins by
Vanda Bednarikova,
Loukia Chatzopoulou and
Sietse Henselmans, which
is part of the Carte Blanche series of exhibitions. The artists are a group of
fourth year students from the AKI, who are also
part of the people creating the Cowmag
zine. Upstairs, Loukia and Sietse made an installation about the history of
the building, which was original build to be an elementary school. At the
landing of the stairs leading up, there were two large CRT monitors, which, if I am mistaken, come from a video wall, that showed two questions about parasites and monuments. Once
you typed in an answer and press return, the answer would just be erased. I
wondered if the answers are stored somewhere. Downstairs was filled by
drawings, lino prints, sculptures resembling termite nests, and two
large symmetrical looking
paintings, which are actually not perfectly symmertical when you take a
closer look, by Vanda. On the left wall there were three progressive lino
prints, which, to me, resembled the paths found in a nest made by insects.
This morning, there was a thin layer of snow on the
table outside and some other places, such as roofs and cars. On Monday, there
was a prediction for a few centimeters of snow on Tuesday. We did not get any
snow, but in the North of the country they did get snow that stayed. There
was some more snow yesterday. This morning there were several locations with
15 cm of snow. During the day there was more very thin snow falling from the
sky that melted immediately on the ground.
At 12:38, I bought the book Letterfontein: over drukletters, fourth
edition, second printing, written by Joep
Pohlen in Dutch and published by Fontana in 2010,
ISBN:9789075084191, from Rataplan for
€ 6.99. I saw this book when I visited the shop and today I went back
to buy it. I also spend some time looking at the Graduation Catalogue from 2015
of the Design
Academy Eindhoven. I found the following projects insteresting:
Today, the temperature went up to 17.9° Celsius at Twenthe Airport coming
close to the record of 18.1° of 2021.
Earlier this week, we still had temperatures far below zero during the night
with a minimum of -6.9°C on Monday and -8.1°C on Tuesday. Today the
temperature did not drop below 9.3°C.
I recieved the book Inleiding tot de elektronica (the manual with
the Philips electronics experiment kits EE 2003, EE 2050, EE 2051, EE 2052,
and EE 2041) written in Dutch and published by N.V. Philips' gloeilampenfabrieken in 1978, which I had bought last
Wednesday from someone on Marktplaats.nl for € 5.00. If I remember correctly, I got an
EE1050 construction kit for my eleventh (or tenth) birthday (based on a
memory of bringing it to school to show it to my class mates). The year before,
my parents gave my an electricity experiment kit with electricity and magnetism
experiments, which resulted in building a very simple DC motor. I still remember the excitement when it barely started running
after hours of building it including winding the coils by hand. The book is
about a later series of the experiment kits, but many of the details in the
book remind me of the book that came with the kit that I got.
In the past weeks, I worked on a new program ECvec.cpp to solve Exact Cover
problems related to calculate the number of solutions for the Fancy Tetris Wooden Puzzle (which is related to the Chinese Wooden Puzzle) and which makes use of ideas from DLX1
program. (I started working on this, because my earlier program crashed on
the puzzle input, probably because it was too large and using too much memory.)
Instead of making columns for the different colours, I decided to group them
together in 'pieces'. Each vector belongs to one of the pieces and when a
vector from a piece is selected all other vectors need to be removed. When they
are grouped together, it is very simple to excluded them without having to
remove them one by one with using the dancing links. I do not know if this really was a good idea, because some
of the columns cover more vectors than some of the pieces. I had hoped that the
new program would generate solutions at a faster rate than the previous program
for finding solutions for the puzzle, but that appeared not to be the case.
After work, I biked to the city center, where I saw the exhibition'(on)waarachtige schoonheid', which could be
translated into English as: '(un)truthful beauty', by Tim Weerdenburg at Fotogalerie Objektief.
This months interesting links
