OpenLLM-France/wikimedia huggingface dataset:
# QBasic/Files

In this lesson, we will learn how to create and modify files. In doing so, we will create a portion of a text editor to handle reading and writing files to and from disk - the program won't be complete by the end of this chapter, but will be finished within Advanced Text Output.
Let's start by setting up out main procedure:
As you can see, we are using CASE rather than IF. IF statements can sometimes work better than case statements, but for now, we want to avoid spaghetti code (where there are too many GOTO's).
So far, we don't really have much, but it's a start. We've asked the user what they want to do, and finished 1/3 options. Not so shabby when you put it that way!

## The OPEN statement

The open statement allows either reading or writing information from the disk. In general, the open statement follows this pattern:
The file$ determines the filename to use. The FOR portion indicates how the file will be accessed or operated - it may be APPEND, BINARY, INPUT, OUTPUT, and RANDOM. The AS # is the identifier used for the file handle in question - this may be a variable if desired.

## Input and output

When you need to access or write content to a file handle, the PRINT and INPUT statements expect a file handle to appear as the first parameter:
In some cases, you need to detect if you are going to reach the end of file - this is performed by the EOF function, which accepts a filehandle that takes input.

## Reading the file from disk

We will now add a subroutine to read the complete file from disk, as lines of text, into an string array called text. It is also possible to read a data file full of numerical values (and input these into a number array), however that is a different topic.
Note the code that finds the file 'size', by reading lines one at a time until the End Of File is reached, and the use of 'SEEK' to 'rewind' to the beginning again.
The example above treats the file as type=text. If the file contains numbers (for example, a data array of N integers per line x M lines) these can be read (input #) one at a time, directly into a numeric array. Input will read the numbers one at a time, 'stopping' after each is input. Numbers can be separated by 'anything' (so lines of text will be skipped).

## Writing a file to the disk

The function for writing a file to disk is easier:

### Part 2: New file

In order to create a new file, you have to open it for OUTPUT, then close it. Example:
NOTE: If you accidently open an existing file, all of its contents will be overwritten!
# Ordinary Differential Equations/Exact 3

${\begin{aligned}&{\text{Question 1:}}\\&{\text{Consider the following equation}}:\\&{\frac {dy}{dx}}+2y={{x}^{2}}{{e}^{-2x}}+5\\\end{aligned}}$
${\text{find the general solution of the above equation}}$
hint: using the following: $y={\frac {\int {{{e}^{\int {P\left(x\right)dx}}}Q\left(x\right)dx}+C}{{e}^{\int {P\left(x\right)dx}}}}$
# Ordinary Differential Equations/Exact equations
## Introduction

Suppose the function $F(x,y)$ represents some physical quantity, such as temperature, in a region of the $xy$-plane. Then the level curves of F, where $F(x,y)={\text{constant}}$, could be interpreted as isotherms on a weather map (i.e curves on a weather map representing constant temperatures). Along one of these curves, $\gamma (x)=(x,y(x))$, of constant temperature we have, by Chain rule and the fact that the temperature, F, is constant on these curves:
$0={\frac {\mathrm {d} F(\gamma (x))}{\mathrm {d} x}}=F_{x}+F_{y}{\frac {\mathrm {d} y}{\mathrm {d} x}}.$
Multiplying through by $\mathrm {d} x$ we obtain $0=F_{x}\mathrm {d} x+F_{y}\mathrm {d} y.$ Therefore, if we were not given the original function F but only an equation of the form:
$M(x,y)\mathrm {d} x+N(x,y)\mathrm {d} y=0,$
we could set $F_{x}:=M(x,y),F_{y}:=N(x,y)$ and then by integrating figure out the original $F$.

## Method formal steps

(1) First ensure that there is such an $F$, by checking the exactness-condition:
${\frac {\partialM}{\partialy}}={\frac {\partialN}{\partialx}}.$
This is because if there was such an F, then ${\frac {\partialM}{\partialy}}={\frac {\partial ^{2}F}{\partialy\partialx}}={\frac {\partial ^{2}F}{\partialx\partialy}}={\frac {\partialN}{\partialx}},$
where ${\frac {\partial }{\partialx}}$ and ${\frac {\partial }{\partialy}}$ simply denote the partial derivatives with respect to the variables $x$ and $y$ respectively (where we hold the other variable constant while taking the derivative).
(2)Second, integrate $M,N$ with respect to $x,y$ respectively: $\int \!M(x,y)dx=\int \!F_{x}(x,y)dx=F(x,y)+a(y)$ $\int \!N(x,y)dy=\int \!F_{y}(x,y)dy=F(x,y)+b(x)$
for some unknown functions $a,b$ (these play the role of constant of integration when you integrate with respect to a single variable). So to obtain $F$ it remains to determine either $a$ or $b$.
(3)Equate the above two formulas for $F(x,y)$:$\int \!M(x,y)\mathrm {d} x+a(y)=F(x,y)=\int \!N(x,y)\mathrm {d} y+b(x).$
(4) Since to find $F$ it suffices to determine $a$ or $b$, pick the integral that is easier to evaluate. Suppose that $\int M(x,y)\mathrm {d} x$ is easier to evaluate. To obtain $a(y)$ we differentiate both expression for $F$ in $y$ (for fixed $x$):$a'(y)=-\int \!M_{y}(x,y)\mathrm {d} x+N(x,y)$and then integrate in $y$:$a(y)=\int \left[-\int M_{y}(x,y)dx+N(x,y)\right]\mathrm {d} y+c.$
(5)Observe that $a$ is only a function of $y$ since if we differentiate the expression we found for $a$ and use step $1$ we find that ${\begin{aligned}{\frac {\partiala}{\partialx}}=&\int \!{\frac {\partial }{\partialx}}\left[-\int \!M_{y}(x,y)\mathrm {d} x+N(x,y)\right]\mathrm {d} y\\=&\int \!\left[-M_{y}(x,y)+N_{x}(x,y)\right]\mathrm {d} x\\=&\int \!0\mathrm {d} x\\=&0\end{aligned}}$
# Ordinary Differential Equations/Existence
### Existence and uniqueness

So, does this mean that if we have an initial condition we will always have 1 and only 1 solution? Well, not exactly. Its still possible in some circumstances to have either none or infinitely many solutions.
We will restrict our attention to a particular rectangle for the differential equation $y'=f(x,y)$ where the solution goes through the center of the rectangle. Let the height of the rectangle be h, and the width of the rectangle be w. Now, let M be the upper bound of the absolute value of f(x,y) in the rectangle. Define b to be the smaller of w and h/M to ensure that the function stays within the rectangle.
    Existence Theorem: If we have an initial value problem $y'=f(x,y),y(a)=b$, we are guaranteed a solution will exist if f(x,y) is bounded on some rectangle I surrounding the point (a,b).
Basically this means that so long as there is no discontinuity at point (a,b), there is at least 1 solution to the problem at that point. There can still be more than 1 solution, though.
    Uniqueness Theorem: If the following Lipschitz condition is satisfied as well
For all x in the rectangle, then for two points $(x,y_{1})$ and $(x,y_{2})$, then $|f(x,y_{1})-f(x,y_{2})|<K|y_{2}-y_{1}|$ for some constant $K$,
then the solution is unique on some interval $J$ containing x=a.
So if the Lipschitz condition is satisfied, and, and $f(x,y)$ is bounded, there is a solution and the solution is unique. If the Lipschitz condition is not satisfied, there is at least 1 other solution. This solution is usually a trivial solution $y(x)=k$ where k is a constant.
We will use two different methods for proving these theorems. The first method is the Method of Successive Approximations and the second method is the Cauchy Lipschitz Method.
Lets try a few examples.

#### Example 9

    $y'=ky,y(10)=500$
Is the equation $f(x,y)=ky$ continuous? Yes.
Is the equation ${\frac {\partial {f}}{\partial {y}}}=k$ continuous? Yes.
So the solution exists and is unique.

#### Example 10

    $y'={\frac {1}{x}},y(0)=5$
Is the equation $f(x,y)={\frac {1}{x}}$ continuous? No. There is a discontinuity at x=0. If we used any other point it would exist.
So the solution does not exist.

#### Example 11

    $y'={\sqrt {y-1}},y(1)=1$
Is the expression $f(x,y)={\sqrt {y-1}}$ continuous? Yes.
Is the expression ${\frac {\partial {y}}{\partial {x}}}={\frac {1}{2(y-1)^{\frac {1}{2}}}}$ continuous for y(1)=1? No. It is discontinuous at y=1 (that is, it is not defined at $y=1$ and is unbounded as $y\to 1$), but continuous for all x.
Lifschitz condition is not satisfied, though the existence condition is satisfied. Hence, the solution exists but need not be unique.
The first solution is $y(x)={\frac {(x-1)^{2}}{4}}+1,x\geq 1$.
The other solution happens to be the trivial one, $y(x)=1$.
# Ordinary Differential Equations/First Order Linear
## First order linear equations
### Lesson 1: Separable equations

* Explanation
* Examples
* Problems
* Answers

### Lesson 2: Graphing differential equations

* Explanation
* Examples
* Problems
* Answers

### Lesson 3: Non-separable equations

* Explanation
* Examples
* Problems
* Answers

### Lesson 4: Substitution methods

* Explanation
* Examples
* Problems
* Answers
# Ordinary Differential Equations/Exact 2

First Order Differential Equations
This page details a method for finding the solutions to equations of the form
    ${\frac {dy}{dx}}+P(x)y=Q(x),$
Using the Integrating Factor: $I(x)=e^{\int P(x)dx}$

## Example 1

Consider the following equation:
    ${\frac {dy}{dx}}+3y=xe^{-3x}+1$
Now the $P(x)=3$ So the integrating factor is:
    $I(x)=e^{\int P(x)dx}$
    $I(x)=e^{\int 3dx}$
    $I(x)=e^{3x}$
Multiply the original equation by $I(x)$
    $e^{3x}{\frac {dy}{dx}}+e^{3x}3y=e^{3x}(xe^{-3x}+1)$
    $e^{3x}{\frac {dy}{dx}}+e^{3x}3y=x+e^{3x}$
Then try: ${\frac {d}{dx}}(ye^{3x})=e^{3x}{\frac {dy}{dx}}+e^{3x}3y$
Which is equal to the LHS giving us:
    ${\frac {d}{dx}}(ye^{3x})=x+e^{3x}$
Then integrate with respect to x:
    $\int {\frac {d}{dx}}(ye^{3x})dx=\int xdx+\int e^{3x}dx$
Giving:
    $ye^{3x}={\frac {x^{2}}{2}}+{\frac {e^{3x}}{3}}+C$
    $y={\frac {x^{2}}{2e^{3x}}}+{\frac {1}{3}}+Ce^{-3x}$ (This is the general solution)
# Ordinary Differential Equations/Exact 4

${\begin{aligned}&{\text{Q1 answer:}}\\&{\frac {dy}{dx}}+2y={{x}^{2}}{{e}^{-2x}}+5\\&y={\frac {\int {{{e}^{\int {P\left(x\right)dx}}}Q\left(x\right)dx}+C}{{e}^{\int {P\left(x\right)dx}}}}\\&{{e}^{\int {P\left(x\right)dx}}}\\&P\left(x\right)=2\\&{{e}^{\int {2dx}}}={{e}^{2x}}\\&Q\left(x\right)={{x}^{2}}{{e}^{-2x}}+5\\&y={\frac {\int {\left({{e}^{2x}}\right)\left({{x}^{2}}{{e}^{-2x}}+5\right)}dx+C}{{e}^{2x}}}\\&y={\frac {\int {{{x}^{2}}+5{{e}^{2x}}}dx+C}{{e}^{2x}}}={\frac {{\frac {{x}^{3}}{3}}+{\frac {5{{e}^{2x}}}{2}}+C}{{e}^{2x}}}\\&{\underline {y={\frac {{x}^{3}}{3{{e}^{2x}}}}+{\frac {5}{2}}+{\frac {C}{{e}^{2x}}}}}\end{aligned}}$
# Ordinary Differential Equations/Definition, reduction of explicit equations to first order

Definition (differential equation in one variable):
A differential equation in one variable is an equation of the form
    $F(x(t),x'(t),\ldots ,x^{(n)}(t),t)$,
where $F$ is a suitable function, to be solved for the function $x$.
# Ordinary Differential Equations/First Order
## First Order Differential Equations

The simplest types of differential equations to solve are the first order equations. These are equations where the highest derivative in the equation is the first. So, a first order equation is a function $F(x,y,y^{\prime })$; there are no occurrences of $y^{\prime \prime }$ or higher derivatives.
There are two easily solved types of first order equations. These are equations with separable variables and linear equations. This chapter covers how to solve and graph any equation in one of these forms, or reducible to these forms. Other types of differential equations, such as non-linear equations, are not covered yet.

### 2: Separable First Order Differential Equations

* Explanation
* Examples
* Problems
* Answers

### 4: First Order Linear Differential Equations

* Explanation
* Examples
* Problems
* Answers

### 1: Exact Differential Equations

* Explanation
* Examples
* Problems
* Answers

### 3: Substitution Methods

* Explanation
* Examples
* Problems
* Answers
===5: Graphing Differential Equations
* Slope Fields
* Isoclines

### Bulleted list item

* Caption2
* File:! Header text !! Header text !! Header text
# Spanish/Verb Phrases
## Hay que y tener que
### Tener que + infinitive

Simply conjugate tener, add que, and then add the infinitive of what has to be done.

#### Ejemplos (Examples)

    Tengo que limpiar mi dormitorio.
I have to clean my room.
    Maribel tiene que salir para escuela.
Maribel has to leave for school.

### Hay que + infinitive
#### Ejemplos

    Hay que estudiar en la clase de ingles. It is necessary to study in English class.
    Hay que practicar

### Contrasting Uses of "Hay que" and "Tengo que"

    Juan tiene una prueba de ingles el viernes. Él tiene que estudiar. Juan has a quiz in English on Friday. He has to study.
    No es fácil aprender el ingles. Hay que estudiar mucho. It isn't easy to learn English. It is necessary to study a lot.

## Ir a + infinitive

This verb phrase is used to say that someone is going to do something in the future. It is often used as an alternative to the future tense.

### Ejemplos

    Voy a viajar en México. I am going to Vacation in Mexico OR I will vacation in Mexico. (same thing)
    Vamos a estudiar por el examen en ingles. We are going to study for our English exam.

## Acabar de + infinitive

Acabar + de + infinitive = to have just (verb in preterite)
'Just' here means very recently in the past.
Por ejemplo:
Acabo de ir al cine. - I have just gone to the movies.
Acabas de hacer la tarea - You just have done the homework.

## Tener ganas de

Tener: to have
Tener ganas de: to want to, to feel like
Tengo ganas de ir al parque. >> I feel like going to the park.
¿Tienes ganas de bailar? >> Do you feel like dancing?
Tener + ganas de + infinitivo >> to feel like (doing) ...
Conjugate tener, add "ganas de" and the infinitive of the action verb.
Note: The verb "ganar" means to earn, to win, or to gain. Joined with the verb "tener" it means to feel like.
# Spanish/Translation Reference/V

vendors = proveedores mayoristas video-hire store (e.g. Blockbusters) = un videoclub vulnerability = vulnerabilidad computacional
# Spanish/Tú-usted

| Lessons: | 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 |
In Spanish, as in many languages, there are two ways of addressing people, one of them familiar and the other formal. In English this is achieved by the use of first names or last names.
Tú is used for people with whom you're familiar. For example, friends and acquaintances would be referred to as tú. So would children, pets, and, usually, all family members.
Usted, which is more formal, is used for people older than you, authority figures, strangers, and people you are meeting for the first time. In parts of Colombia usted is widely used, even among friends.
| | tú-tú | usted-usted | tú-usted |
| | Friends or acquaintances. | Strangers or recent acquaintances. | Use of usted when the other person expects tú shows distance or contempt. |
| | Online, people prefer to keep conversation informal by referring to each other in the "tú" form, whether they've met before or not. | | Online, this is equivalent to the English use of sir. E.g. usted es un excellente professor means you, sir, are an excellent professor. |
| * | Relatives | Relatives (rare) | Older relative-Younger relative |
| | People of the same age | People with big age difference | People with big age difference (the young one uses usted) |
| * | Colleagues who know each other | Recent business acquaintances | Boss-subordinate |
| | | | Person with high social status-Person with low social status. See below. |
| | | | Use of tú when the other person expects (or should expect) usted shows disrespect. e.g. police officer to crime suspect |
* Depends a lot on the country

## See also

* Personal pronouns
* Vos (advanced topic)
# Spanish/Users

If you have used this Wikibook to learn Spanish, please add your name to the list below. This helps us see how many people are using this Wikibook. If you are a user, please use your signature by typing . If you are not a user, either leave your name or just list yourself as Anonymous.
# Spanish/Translation Reference/U

ultimate = extrema, final update = actualizada, actualización unable = incapaz unauthorized = inautorizado unclear = incierto underbrush = sub-arbusto undergo = sufrir undersecretary = subsecretario undoubted = indudable uneasy = inquieto unsafe = inseguras up to = hasta upcoming = futuro upgrade = actualización usher = acomodar
# Spanish/Verbs

    Verb Phrases
    Verb Tenses
    Verbs List
    Reflexive Verbs
    How To Conjugate Verbs

## Ejemplos

* Verbos regulares
** Amar (regular -AR verb)
** Temer (regular -ER verb)
** Partir (regular -IR verb)
* Verbos auxiliares
** Haber
* Verbos irregulares
** Ser
** Estar
** Ir
** Hacer
* Otros verbos irregulares
** Gustar
** Llover
* Futuro irregulares
** Poder
** Querer
** Saber
** Caber

## Expressions

* Expressions using the verb hacer
* Expressions using the verb tener

## Otras temas de los verbos
### Verbos con la voz pasiva

An action takes place without anyone being assigned responsibility for doing it.
* The Passive Voice

### Verbos reflexivos

Reflexive verbs indicate that the action of the verb reflects back on the subject.
* Reflexive Verbs

### External Links

* spanish.allinfo-about.com verb index
* studyspanish.com verbs
Spanish Wikibook | Verb Tenses | Verbs List
# Spanish/Translation Reference/W

wrangle = disputas wrapped = envuelto warning = advierte wave = ademanan saludos way in which = método wealthy = prósperos weather = se trata sobre si wear out = desgastando, perdiendo when = mientras when it comes to = referente a whether = sin contar si, sobre si wide = extenso widely = comúnmente widely-used = popular widespread = común, general wild goose chase = caza descabellada, descabellada cacería wipe = borrar, restregar wire services = teledespachos within = a work = laboran world = contorno waiting in the wings = en progreso se encuentra
# RAC Attack - Oracle Cluster Database at Home/RAC Attack 12c/Linux Post Installation With Internet

Prev: Prepare Host
* Create VirtualBox VM
* VirtualBox VM Settings
* OS Installation
* Linux Post Installation
* Install VirtualBox Addons
* Configure Bind DNS
* Prepare Linux for Oracle
Next: Create Cluster
* To connect to the new created virtual machine, create a connection in Putty for the new VM called collabn1 with the IP Address of 192.168.78.51.
* Open the collabn1 connection by clicking Open. Click Yes on the Security Alert dialog box.
* Enter root at the login as: prompt and racattack at the password: prompt.
* Turn off and disable the firewall IPTables.
* Disable SELinux. Open the config file and change the SELINUX variable from enforcing to disabled.
* Verify that all the network interfaces are up.
* If you have configured eth2 to connect to the internet, verify that you can ping a website on the internet.
* If you are connecting to the internet with a proxy, you need to add these lines in your /etc/yum.conf file:
* Install the database preinstall package oracle-rdbms-server-12cR1-preinstall.
* Install additional RPMs that will be used to install and administer the servers.
* Uninstall NTP.
* Optionally, update all your packages to the latest version. Don't do it during a RAC Attack event, it may take too much time to be completed within the session.
# RAC Attack - Oracle Cluster Database at Home/RAC Attack 12c/Install Grid Infrastructure
## RAC Attack - Oracle Cluster Database 12c at Home (e)

    Overview
    Events
    Local Manual of Style
    Bullpen (Newly Contributed Content)
    Expanded Table of Contents

#### Part I: Setting Up RAC

* Hardware Requirements
* Software Components
* Prepare Host
* Install Linux
* Create Cluster
* Install Grid Infrastructure
* Install Database Software
* Create Database

#### Part II: Exploring RAC

* Cluster Testing
* Services, Failover and Load Balancing

##### Part II still in development phase
#### Part III: Advanced Labs

* Flex Cluster and Flex ASM
* Policy Managed Database

##### Part III still in development phase

Prev: Create Cluster

## Install Grid Infrastructure

* Prepare for GI install
* Install Grid Infrastructure
* Check Cluster Status After GI Install
* ASM Configuration
Next: Install Database Software
# RAC Attack - Oracle Cluster Database at Home/RAC Attack 12c/Install VirtualBox Addons

Prev: Prepare Host
* Create VirtualBox VM
* VirtualBox VM Settings
* OS Installation
* Linux Post Installation
* Install VirtualBox Addons
* Configure Bind DNS
* Prepare Linux for Oracle
Next: Create Cluster
* Make the VirtualBox guest additions available to the OS by clicking Devices->Install Guest Additions.
* Mount the virtual CD-Rom created by VirtualBox.
* Install the VirtualBox Guest Additions. The error related to the step Installing the Window System drivers is ok to ignore, it will not appear on newest VBox versions.
* Dismount the cdrom.
# RAC Attack - Oracle Cluster Database at Home/RAC Attack 12c/Install Grid Infrastructure (ASM)

Prev: Create Cluster
* Prepare for GI install
* Install Grid Infrastructure
* Check Cluster Status After GI Install
* ASM Configuration
Next: Install Database Software
* From the VNC remote session, run the installation of Grid Infrastructure as oracle:
* The Installation starts displaying a Splash Screen:
* Leave Skip software updates and click Next:
* Leave Install and Configure Oracle Grid Infrastructure for a Cluster and click Next:
* Leave Configure a Standard Cluster and click Next:
* Leave Typical Installation and click Next:
* In the SCAN Name box, enter collabn-cluster-scan.racattack
* Click SSH connectivity...
* Enter racattack as the password of oracle user and click Setup.
* The setup of SSH equivalency is initiated.
* Click OK when it's completed.
* Click on Identify Network Interfaces...
* Some prerequisite validation is done at this step. It can require some minutes to complete.
* Since the SCAN Name chosen is too long (more than 15 chars.) Oracle proposes a different name as the Cluster Name. Click Yes.
* Leave the default Oracle Base and Software Location.
* racattack is a weak password and Oracle raise an alert. Click Yes to continue:
* Leave DATA as Disk Group Name.
* Check two disks that will be immediately allocated to the new disk group.
* Leave the default Inventory Directory. Click Next.
* Check Automatically run configuration script and then Use "root" user credentials.
* It takes some time to complete the prerequisite checks.
* If everything is correct, you will notice two checks that have failed:
* Click Yes to confirm that you want to skip some prerequisites.
* The summary page appears. Optionally, click Save Response File and choose a location to have the response file saved for this installation session.
* Review the summary and click Install to start the installation.
* The installation starts. It may take more than an hour, depending on your laptop hardware.
* After a while, the installation asks a confirmation before running some scripts as root. Click Yes to continue.
* The installation continues, again, it may take longtime to complete. Once it's finished, click on Close to exit.