OpenLLM-France/wikimedia huggingface dataset:
# Muggles' Guide to Harry Potter/Magic/Peruvian Instant Darkness Powder
## Overview

Peruvian Instant Darkness Powder is, as the name suggests, a powder which renders an area instantly dark when it is thrown.

## Extended Description

A product of Weasleys' Wizard Wheezes, Peruvian Instant Darkness Powder is one of the more serious products that the Twins sell to the Ministry of Magic and similar organizations. We see it in the back room of the Twins' shop when Fred and George are showing Harry around.
Somehow, Draco Malfoy manages to purchase some of this material, and uses it to mask the invasion of Hogwarts from the Room of Requirement in Harry Potter and the Half-Blood Prince. When the powder is thrown at Ron, Ginny, and Neville, they are unable to see anything, which means that it must have blocked all light from entering the region where the powder was thrown; however, Draco, who has a Hand of Glory, is still able to see to lead the invading Death Eaters past them.

## Analysis

On its own, this would seem to be not particularly useful; what is the use of having an area suddenly become totally dark? Particularly if you must travel through that area yourself, it seems counter-intuitive to eliminate your own ability to see what you're doing. In the book, however, Draco pairs this with the Hand of Glory, which will illuminate the resulting darkness only for him. He is then able to lead a train of Death Eaters out of the darkened area, while those set to watch him are left in the dark. It is uncertain why the darkness powder does not affect the light of the Hand Of Glory; perhaps the Hand of Glory somehow makes use of a part of the spectrum other than that affected by the darkness powder.
The mature reader can't help wondering if the name of this substance is derived from "Bolivian marching powder", a slang term for cocaine.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Muggles' Guide to Harry Potter/Magic/Peskipiksi Pesternomi
## Overview

Peskipiksi Pesternomi is not a real spell.

## Extended Description

This spell appears to be Gilderoy Lockhart's attempt at a spell to disperse the Cornish Pixies he released in one of his Defence Against the Dark Arts classes, but it didn't work, and it might even have further irritated the pixies in question. The immediate result seems to have been that one of the pixies grabbed Lockhart's wand and threw it out the window.

## Analysis

The spell incantation seems to be based on the English phrase "Pesky pixie, pester no me". As most real spells seem to have incantations that derive from Latin words, the fact that this one is based on an English phrase makes it immediately suspect.
Given the nature of his actual magical expertise, which we discover late in the books, it is uncertain whether Lockhart had ever really tried to use this spell. Equally, it is uncertain whether he created this spell himself, or was given it by someone who didn't completely trust him. We see throughout the book that the teachers at Hogwarts seem to have a very low opinion of Lockhart's magical skill.
The purpose of this spell seems to be purely to point up Lockhart's incompetence.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
* What is the effect of this spell?
# Muggles' Guide to Harry Potter/Magic/Plimpy
## Overview

Plimpies are apparently aquatic, but are never described in the series, though they are mentioned by both Luna Lovegood and her father Xenophilius.

## Extended Description

In Harry Potter and the Half-Blood Prince, we learn from Luna Lovegood that Gulping Plimpies can be staved off by means of Gurdy-roots.
In Harry Potter and the Deathly Hallows, Xenophilius Lovegood explains Luna's absence by claiming that she is down on the far side of the bridge, catching Plimpies for their supper. He says that many people have asked for the recipe for their Plimpy soup.
In Magical Beasts And Where To Find Them, there is a description of Plimpies. Evidently these are approximately spherical fish with legs and feet. It is mentioned that Merpeople can get irritated by their habit of hovering around, and will tie their feet together. A Plimpy with its feet tied together will drift helplessly until it manages to get its feet untied, which can take hours.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Muggles' Guide to Harry Potter/Magic/Petrificus Totalus
## Overview

Petrificus Totalus is a spell that freezes or petrifies the body of the victim, making it incapable of moving, except for the eyes and breathing. It is also known as the Body-Bind Curse or the Full Body-Bind, the latter being used apparently to differentiate it from Locomotor Mortis, the leg-locker curse. The spell can be broken by the Finite Incantatem spell.

## Extended Description

This is apparently a fairly simple spell, as Hermione uses it on Neville late in the first book.
Harry will use this spell himself on a number of occasions. Perhaps interestingly, it is almost exclusively used against Dolohov, who is twice petrified by Harry in the battle at the Ministry of Magic in Harry Potter and the Order of the Phoenix, and at the top of the Astronomy Tower in Harry Potter and the Half-Blood Prince, then by Hermione in the all-night cafe in the Tottenham Court Road, and finally by Parvati Patil in the climactic final battle in Harry Potter and the Deathly Hallows.
It will be used by others on Harry as well; notably, in Harry Potter and the Half-Blood Prince, Draco Malfoy will petrify Harry and break his nose, and later in the same book, Professor Dumbledore will petrify Harry to keep him out of the action and safe. Once Dumbledore is killed, the curse wears off on Harry.

## Analysis

The Harry Potter story arc, consisting as it does of an epic struggle between good and evil, will have fights, larger battles, and perhaps even an all-out war. In order to prevent the series, ostensibly for children, from becoming excessively dark, there must be non-lethal weapons for the protagonists to use. To that end, the author has provided us with a number of disabling spells, ranging from the simple stunning, disarmament, and binding jinxes, through to those with humorous effects. It is uncertain why there would need to be so many different ways to disable, but we can surmise that the author has at least some reason for use of each variety. Notably, the full body-bind jinx here leaves the subject fully aware of what is happening, able to see and recall what proceeds around him after he has been jinxed.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.

## Greater Picture

It is mentioned above that a person disabled by means of this jinx retains his sight and the ability to observe and recall events occurring around him. Apparently this knowledge of the passing scene on Dolohov's part is what alerts Voldemort to Harry's escape from Death Eaters in the Tottenham Court Road coffee house, after his departure from The Burrow in Harry Potter and the Deathly Hallows. Voldemort would not, otherwise, have any reason to punish Rowle for allowing that escape. As such, it is a useful plot point; knowing that Harry is no longer at any of the Order of the Phoenix safe-houses, Voldemort is likely to hold off on further torture of occupants of those houses, including Ron's family.
# Muggles' Guide to Harry Potter/Magic/Phoenix
## Overview

A Phoenix is a magical bird that periodically burns up and is then reborn from its own ashes.

## Extended Description

Phoenixes are truly remarkable birds. While their rebirth from their own ashes is relatively widely known among Muggles, it is not generally known that they can lift extremely heavy loads, that their tears have healing powers, or that they are extremely loyal pets. We are introduced to one phoenix in the course of the books: Fawkes is Professor Dumbledore's pet phoenix.

## Analysis

While we are not introduced to the bird itself in Harry Potter and the Philosopher's Stone, there is mention of the phoenix in that book; Mr. Ollivander mentions that there is a phoenix feather at the core of Harry's wand. Ollivander mentions also that the phoenix in question has only ever given two feathers; but since he mentions that his wands are made with phoenix feathers, dragon heartstrings, or unicorn hairs, one can safely assume that there are other phoenixes that he can harvest feathers from. Note that Ollivander selecting these items for the core of his wands indicates that he believes them to be the most powerful magic items available.
Fawkes' special powers play a very large part in Harry's defeat of the monster in the Chamber of Secrets: it is his loyalty that calls Fawkes to Harry, the healing powers of his tears are what restore Harry to health after he is injured by the monster, and it is his ability to lift heavy loads that allows Harry to escape from the Chamber with Ron, Ginny, and Professor Lockhart after the monster has been destroyed.
His loyalty and intelligence are extremely useful to Dumbledore in Harry Potter and the Order of the Phoenix, where Dumbledore has Fawkes carry messages and keep a lookout.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
* Why is there a phoenix feather in Harry's and Voldemort's wands? Does it signify a wand whose wizard/witch's strength is duelling?
* Phoenixes are shown as not really belonging to the realm of ordinary magic, or ordinary Magical Beasts, but quite extraordinary; and there is only one we see in the entire series. Yet for Ollivander, phoenix feather is a quite regular material to create wands from. How many phoenixes then exist?
* Most people would, it seems, wish for a Phoenix as a pet - but we cannot imagine them being sold in the Magical Menagerie in Diagon Alley or some such place. How then do you get a phoenix? What do you need to be to "qualify" for having one? How did Dumbledore come to own Fawkes?
# Muggles' Guide to Harry Potter/Magic/Photograph
## Overview

Magical photographs are similar to Muggle photographs, except that the people portrayed in them are animate, moving, waving, and apparently dropping out of the picture occasionally to attend to other business. They act in many ways as their originator would in similar situation: a photograph of a girl develops spots on her nose at one point and starts trying to hide her face under the picture frame, for instance.

## Extended Description

While very similar to magical Paintings, photographs seem to be lesser variants of the breed; while the characters are animate, they do not seem to interact with occupants of other photos, and they do not seem to interact much with the people outside the photograph (in fact, they don't seem to be able to speak at all) – although in Harry Potter and the Order of the Phoenix, Alastor Moody does instruct the characters in a photograph to "move aside", and they apparently do so. Printed images behave similarly to photographs; the pictures in The Daily Prophet, for instance, move but don't speak either.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Muggles' Guide to Harry Potter/Magic/Pixie
## Overview

Pixies are small, electric blue flying creatures, the ones we see in the books originate in Cornwall, and are very mischievous.

## Extended Description

During a Defence Against the Dark Arts lesson in Harry Potter and the Chamber of Secrets, Professor Lockhart lets loose a cage full of pixies, in spite of the fact that he has no experience with them at all. Havoc breaks loose while Lockhart tries to control the situation, in vain, and uses the absolutely non-effective spell Peskipiksi Pesternomi (which was most likely made up). Lockhart flees with the rest of the class, leaving Harry, Ron, and Hermione to clean up the mess.

## Analysis

Given what we find out about Lockhart at the end of this book, it is uncertain whether Lockhart could have known that the charm he proposed would work. It is certain he had never tried it before. It is possible that some witch had given him the charm, and he had written about it before erasing her memory; but the witch quite possibly knew Lockhart's reputation and had given him a false and ineffective spell.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Optimizing C++
## Preface
### Audience

This book is for intermediate C++ programmers (i.e. studying C++ for at least one year) who want to improve the performance of the software they develop.

### Subject

This book contains guidelines and advices on how to write efficient software using the C++ language. Software correctness and maintainability are taken into account, but are not the primary concerns of the guidelines.
Most of the guidelines presented are not platform specific, and so are applicable to every processor, to every compiler, and to every operating system; the few platform specific advices try to cover most platforms.

## Table of Contents

* Introduction
* Optimization life cycle
* Writing efficient code
** Performance improving features
** Performance worsening features
** Constructions and destructions
** Allocations and deallocations
** Memory access
** Thread usage
* General optimization techniques
** Input/Output
** Memoization
** Sorting
** Other techniques
* Code optimization
** Allocations and deallocations
** Run-time support
** Instruction count
** Constructions and destructions
** Pipeline
** Memory access
** Faster operations
** Compile time optimization
* Tools
* Further reading
Guidelines for editors
# Optimizing C++/Code optimization

In this chapter some techniques, specific for C++ language, are proposed. They are to be applied only in bottlenecks, as, although they may speed up execution, they also make more complex and less maintainable the source code.
In addition, such guidelines in some cases could worsen the performance instead of improving it, and therefore their effect should be always measured before releasing them.
The optimization techniques are grouped according their goal.
* Allocations and deallocations
* Run-time support
* Instruction count
* Constructions and destructions
* Pipeline
* Memory access
* Faster operations
* Compile time optimization
# Optimal Classification/Rypka Method/Examples/Computational
## Bounded Class Dimensions

G = 28 - 28 elements - i = 0...G-1
C = 10 - 10 characteristics or attributes - j = 0...C-1
V = 5 - 5 valued logic - l = 0...V-1

## Separatory Values

max(T) = 309 = S$_8$ = highest initial separatory value

## Notes

* ↑ Mathcad's ORIGIN function applies to all arrays such that if more than one array is being used and one array requires a zero origin then the other arrays must use a zero origin with all variables being adapted as well.
# Optimizing C++/Code optimization/Compile time optimization

* When possible put code that is reused into .cpp files and compile as reusable libraries instead of placing more code in header files to minimize the amount of redundant compilation.
* Use templates to speed up compile time by compiling the parts of the interface that you use rather than compiling every possibility all the time, one particular use case here is for macros.
* Minimize included code to only include the exact features you need, rather than using catch all include files
* Use forward declarations to avoid including files because it completely eliminates redundant compilation of code.
# Optimal Classification/clustering

Many people consider clustering the most important unsupervised learning problem. Clustering deals with finding structure in a collection of unlabeled data.
Clustering has many practical applications.
Many clustering algorithms ( k-clustering algorithms ) require a human to specify ahead of time how many buckets (categories, labels, classes, etc.) to divide up the input into.
* Median cut clustering -- perhaps the fastest clustering algorithm
* K-means clustering -- a very fast clustering algorithm, with the disadvantage that it does not provide the same result with each run.
* QT clustering algorithm
* expectation-maximization algorithm
* canopy clustering algorithm
* constrained clustering
* Fuzzy clustering by Local Approximation of MEmberships (FLAME clustering)
* self-organizing map
* vector quantization
* Learning Vector Quantization

## further reading

* Artificial Neural Networks/Clustering
* Proteomics/Protein Chips/Algorithms
# Perl Programming/Keywords/getlogin
## The getlogin keyword

The getlogin function implements the same C library function. On most UNIX-like systems, this function returns the current login from /etc/utmp, if any. On an empty string, the function getpwuid should be used.
As getlogin is not as safe as getpwuid, the latter should be used for authentication.

### See also

* getpwuid
# Perl Programming/Keywords/getpgrp
## The getpgrp keyword

The getpgrp function returns the current process group of the PID. For the process group of the current process, the PID should be set to 0 or should be omitted. If Perl is implemented on a machine that does not implement getpgrp(2), an exception is raised. On POSIX systems, a PID is not accepted.
# Perl Programming/Keywords/gethostbyname
## The gethostbyname keyword

The gethostbyname function gets the group record given its NAME.
# Perl Programming/Keywords/getnetbyaddr
## The getnetbyaddr keyword

The getnetbyaddr function gets the network record given its ADDRESS and ADDRESSTYPE.
# Perl Programming/Keywords/getnetent
## The getnetent keyword

The getnetent function gets the next network record.
# Perl Programming/Keywords/getpeername
## The getpeername keyword

The getpeername function returns the packed socket address from the other end of the SOCKET.
# Perl Programming/Keywords/getppid
## The getppid keyword

The getppid function returns the process ID of the parent process.
# Perl Programming/Keywords/gethostent
## The gethostent keyword

The gethostent function gets the next host record.
# Perl Programming/Keywords/getnetbyname
## The getnetbyname keyword

The getnetbyname function gets the network record given its NAME.
# Perl Programming/Keywords/getpriority
## The getpriority keyword

The getpriority function returns the current priority for a process, a process group, or a user. Raises a fatal exception, if used on a machine that doesn't implement getpriority(2).
# Operating System Design/Case Studies/BSD

BSD, or Berkeley Software Distribution, is a UNIX operating system developed at the University of California, Berkeley. Started in 1977, it introduced many technologies still in use by operating systems today. It was the first OS of its kind to implement libraries supporting the Internet Protocol, allowing for easy read/write across a network.
Although the project died in 1995, it gave birth to multiple popular derivatives such as FreeBSD, NetBSD, and OpenBSD.
# Operating System Design/Case Studies/BeOS

BeOS is an operating system for personal computers. It was under development from 1991 until development was discontinued in 1997. Although it has partial compatibility with POSIX and a Bash shell, it is not based on Unix sources and remains closed-source.
The open-source Haiku operating system aims to pick up where BeOS left off. It began development in 2001 and became self-hosting and 2008.
# Operating System Design/Case Studies/MINIX

MINIX is a Unix-like operating system developed by computer science professor Andrew S. Tanenbaum. While originally devised as a teaching tool, it has found use (particularly in its latest incarnation, MINIX 3) as a reliable OS for embedded systems and computers with limited resources. Its stability can be attributed largely to its microkernel architecture, which has device drivers and the like contained in user space rather than kernel space.
# Operating System Design/Case Studies/GNU Hurd

GNU Hurd is a kernel for GNU, a free Unix-like operating system developed by the GNU Project. Hurd was initiated in 1990 to add the only missing feature in the GNU operating system ‒ a kernel. Although under development for over 20 years, there is still no stable release.
It consists of a group of 24 server processes that run on the Mach microkernel. These servers provide most OS features, from authentication to filesystems.
# Operating System Design/Case Studies/Mac OS X

XNU (X is not Unix), the kernel of the Mac OS X operating system, is a hybrid. It is based on Mach, a microkernel, but also incorporates elements from BSD, which is monolithic. Thus, it has some of the advantages and disadvantages of both.
# Operating System Design
## Table of Contents

* Preface
* Introduction
* Case studies
* History

### Kernel Architecture

* Monolithic Kernel
** Solaris
** Linux
** Windows 9x
** BSD
* Microkernel
** GNU Hurd
** MINIX
** QNX
* Exokernel
** XOK
* Hybrid Kernel
** Mac OS X
** Windows NT/XP
** BeOS

### Initialization

* Bootloader
* Hardware Initialization

### Processes

* Interrupts
* Context Switching
* Scheduling
** First Come First Served
** Shortest Process Next
** Shortest Remaining Time
** Round Robin Scheduling
** Preemption
** Priority Scheduling
* Concurrent Processing
** Deadlock
** Livelock
* Interprocess Communication
** Locks
** Signals
** Semaphores
** Monitors
** Shared Memory
* Threads (Lightweight Processes)
* Fibers (Lightweight Threads)

### Memory Management

* Physical Memory
* Segmentation
* Virtual Memory
** Paging
** Swapping
* Basics
** Allocation Algorithms
* Fault Tolerance

### File Systems

* Abstraction
* Allocation Algorithms
** Performance
* Fault Tolerance
** RAID
** Journaling
** Dealing with Bad Blocks
* Case Studies
** File Allocation Table (FAT)
** NTFS
** ext4
** BTRFS
** ReiserFS
** HFS
** ZFS

### Security

* Access Controls
** Users
** Resources
* Privileges

### Interface

* Command line interfaces
* Graphical user interfaces
** Desktop environment
** Configuration tools
** User Ability
# Operating System Design/Case Studies/Linux

80386 computer, and the initial versions were technically limited and only supported the i386 architecture. With contributions from dozens of other FOSS programmers, support for numerous features and architectures was added.
Linus originally started the project as an updated replacement for Minix, which was written by Andrew S. Tanenbaum to use as an example for an operating system design and implementation course. Many Linux distributions combine the kernel with many of the GNU utilities.
# Pinyin/Court

See also
# Pinyin/Cover

See also
# Pinyin/Country

See also

## Noun

* a country is an area of land that has its own government and official borders.
** guorjia shih yoou zhehngfuu her liingtuu d dihfang.
# Pinyin/Crabapple

Search Pinyin apple
A crabapple is the fruit of a crabapple tree. A crabapple tree is a kind of apple tree with a small and sour fruit.
Hǎitángguǒ shì hǎitángshù de guǒshí. Hǎitángshù shì guǒshí xìxiǎo érqiě hěn suān de yīzhǒng píngguǒshù.
# Pinyin/Country's

See also
# Pinyin/Couple

See also
# Pinyin/Cow

See also
# Origami/Types/Standard Origami/Cube

The cube is based on the waterbomb base.
# Origami/Types/Modular Origami/Flower

There is a lot of flower origami models. This one needs two square papers.
# Origami/Types/Standard Origami

Here is a list of ordinary origamies.
* Cube
* Snail
# Origami/Types/Pureland Origami/Helmet

The helmet is a samurai helmet. It is based on the helmet base.
# Origami/Types/Wet Folding

Wet folding is the practice of wetting origami paper with water and folding the model while the paper is wet. It is a useful method for folding organic forms, since the paper will permamently retain subtle folds and curves after it dries.
# Origami/Types/Pureland Origami

Pureland origami is origami with the restriction that only one fold may be done at a time, more complex folds like reverse folds are not allowed, and all folds have straightforward locations. It was developed by John Smith in the 1970s to help inexperienced folders or those with limited motor skills. Some designers also like the challenge of creating good models within the very strict constraints.
* Helmet
* Star