koku's life journal

it happened again.. i didn't update for a few days and gotten too overwhelmed by the backlog, which is exactly what made me give up last semester.. so this time i'll avoid it by just skipping days whenever this happens, and fingers crossed it won't any time soon!!

NMAI058 (Linear algebra 2) [lecture] - eigenvalues of linear maps and matrices.. what is an eigenvalue anyway, right? linear algebra is already going over my head and the semester started only a month ago..

NTIN060 (Algorithms and Data Structures 1) [lecture] - sharir's algorithm for finding the strongly connected components of an oriented graph and algorithms for finding the shortest path in an oriented graph, but we only had time for dijkstra's algorithm, my beloved

i now have a three hour block of free time again, although this time it's every week, since I was getting tired of eating fast food and supermarket baguette sandwiches all the time, i went to miyabi, a japanese restaurant near lazarská, got two onigiri and some tsukemono to go, then took the tram to výstaviště, where i ate it, it tasted pretty good

NTIN107 (Extension seminar Algorithms and Data Structures 1) - i started attending last week, but i didn't blog about it, this seminar uses algovision.org, a website created by the professor, to visualise the various algorithms and data structures, he goes over it and explains it, we did spanning tree algoritms, which are curious because two of them have been discovered by czechs, later rediscovered by other people, those being the jarník-prim algorithm and the borůvka algorithm, but i like kruskal's algorithm (who was british) because when the professor introduced the problem that was the algorithm i have come up with on the spot myself!!

NJAZ072 (English for upper-intermediate students II) - future stuff, as in talking about where we see ourselves and the world at large in 1/10 years, phrases including the word time and a group exercise where there were 4 superpowers with a drawback and everyone in a group got assigned one who had to defend it, i had time travel but you age 2x as fast, my defence was talking about how you could have infinite money via the stock exchange and use that money to buy all those anti-aging product that people talk about on tiktok

NSWI170 (Computer systems) [lecture] - pointers and references and similar things idk..

went to the library to borrow the arduino before class started, no NSWI170 today as it's only every other week

NMAI054 (Mathematical analysis 1) [tutorial] - focusing on properties of sets of numbers..like: suprema, maxima, infima and minima of subsets of rationals and reals, which properties (like a set being bounded, being countably infinite etc.) imply other properties and at the end suprema and minima of generalized sets, like supremum/infimum of the union of two sets or a set created by summing every member of each set with the other and such, i got a lot of things correct

NPRG031 (Programming 2) [lecture] - c#, not too dissimilar from the lecture for NSWI170 from yesterday, just with c# instead of c++, i've found out how .dlls happen and about the LI, which is analogous to the java virtual machine.. also how to pass a variable as a reference instead of a value to a function

NMAI054 (Mathematical analysis 1) [lecture] - we haven't begun calculus just yet, just did things about infinite sets of numbers, like the natural, integers, rationals, reals and complexes (complices?), proof that rationals and below are countable infinities, and proof that the reals form an uncountable infinity, attributes of subsets of the reals, like minimum/maximum, infimum/supremum and similar

NPRG031 (Prgramming 2) [tutorial] - no programming just yet, as we don't really know much about the syntax of c#, so we had an exercise in what the teacher called train sort.. we were given a series of marshalling yard shapes and we had to decide whether it could be used to sort any arbitrary array of n trains, essentially trying to prove whether a combination of LIFOs, FIFOs and connections between them could be used to permute any word of length n, so more to do with permutations than sorting, also we among other things used an approximation of n! to prove that if you have any constant amount of stacks where you can only move in to the first stack, from the nth stack to the (n+1)th stack, and from the last stack out, you cannot sort a sufficiently large amount of trains gosh i have a lot to say

I'm sorry for having given up blogging, i'm gonna start again, as the second semester has started today

NSWI170 (Computer systems) [tutorial] - this is a sort of continuation of NSWI120 from last semester, except more hands on, we'll be programming in C/C++ and also programming arduinos, so more low level than what we've done prior, we told some administrative things about the class, like how homework works and what we have to do to be allowed to the exam, then we did very simple programming things in C++ (printing and working with arrays)

NMAI054 (Mathematical analysis 1) [tutorial] - calculus!!! because we haven't had the lecture yet we only did revision of high school things we should already know, like inequalities in the reals of functions with abs, logs or fractions and drawing specific functions.. in high school we did a lot of calculus so i hope i won't struggle in this class...

NPRG062 (Introduction to algorithms) [lecture] - recursion, see also: today's daily message, including the classic example of the fibonacci sequence, how to deal with unnecessary calculation of the same things by using caching or by building from the bottom up and the best way to do it, which uses matrices, you raise the matrix ((0,1),(1,1)) to the nth power and then multiply by the vector (f0,f1), you can use the quick raising to the power by using the binary representation of n, gosh this is a long entry, we also did recursive generation, like how to break up a number into all the sums it can be made of

NPRG030 (Programming 1) [lecture] - int("number") isn't actually a function, it's a constructor! most of the class was focused on working with files, things i know and we did during the tutorial previously.. also the way strings are interpreted in memory (they terminate at a specific char, like c strings) and the walrus operator := which has a silly name methinks

NPRG062 (Introduction to algorithms) [tutorial] - went over homework and then did some things regarding binary heaps and linked lists, i've come to the conclusion that i like heaps, what a silly data structure

NPRG030 (Programming 1) [tutorial] - linked lists, specifically working towards the homework we have where we are given a series of natural numbers and we have to, using a linked list, sort it in a way that first are the sorted evens then sorted odds

NJAZ070 (English for Upper-Intermediate Students I) - i did pretty well on the test! 26/30 with the best score in the class being 27/30, after going over the test answers and the homework we were told about how to structure the essay we're writing in 3 weeks.. i'm a little afraid of it, as i always am with essays, for what if none of the subjects speak to me.. it's going to be an argumentative essay, with the little time left we also did some thing from the book..

no adventure this week because i was feeling really week and also i couldn't find a place i wanted to adventure in..

NMSA230 (Introduction to R programming) - data frames! good way to structure data and work with it it seems, how to merge multiple data frames together, how to make subsets, how to analyse them and the library stargazer, which creates a TeX table from a data frame, around the end we also found out how to extract data from a csv/excel

NMAI069 (Mathematical skills) - just set theory nothing much of note.. next week we have a quiz

NDMI002 (Discrete mathematics) [lecture] - probability, defined the random variable and expected value of a random variable, trivial proof of linearity of expectation.. then markov's inequality, only used to prove chebyshev's inequality we'll see what use that has sometime else

NDMI002 (Discrete mathematics) [tutorial] - a quiz that i've made a small mistake on and also didn't write out that well, some problems on probability including the classic 20 people who don't share a birthday problem but also others like electronics with a fixed chance of being broken and sex assigned at birth, all pretty simple things

NPRG062 (Introduction to algorithms) [tutorial] - went over what we did on the lectures, mostly focusing on the data structures of lifo fifo and the linked list, i also realised on my own that if you go through a list using the stack over and over you can leave with any permutation you want because you can a transposition by taking right after every put except for the first of the two you want to swap and after the second one you want to swap you take two.. and you can reach any permutation using a series of transpositions

NPRG030 (Programming 1) [tutorial] - reading from a file and making graphs using matplotlib! homework is to parse a csv of the weather in prague since 1775 and make some graphs of it

NJAZ070 (English for Upper-Intermediate Students I) - test.. i did all of it except for forgetting a synonym for compliment s/o.. i hope i did well though.. also went over homework about imperatives in maths (prove, define, take etc.) after that we started the next chapter of the book

NPRG062 (Introduction to algorithms) [lecture] - proof that the best big O of a sorting function is nlog(n) using a binary tree and stirling's formula for approximating factorials, after we did count and bucket sort, both having O(n+R) where R is the difference between min and max of input data and radix sort having O(n*logR), after we did data structures, something about lists.. and abstract data structures: stack (fifo) and queue (lifo)

NPRG030 (Programming 1) [lecture] - tuples, dictionaries and objects, apparently big o of a dictionary is O(1) except for when it sometimes isn't.. and an implementation of linked lists