R Programming Essentials: Data Manipulation & Visualization
R Data Handling Essentials
Importing Data
Importing CSV Files
Use
read.csv()to import a Comma Separated Values file:df <- read.csv("filename.csv")
Importing Stata .dta Files
Requires the
havenpackage:library(haven) df <- read_dta("stata_file.dta")
Managing Your Environment
Setting and Checking the Working Directory
Set:
setwd("your/path/here")Get:
getwd()
Data Frame Basics
Accessing a Column
Access a column using the
$operator:df$column_name
Calculating Column Mean
Calculate the mean of a numeric column:
Chilean Education Transformation: Key Reforms (1920s-1930s)
Chilean Education Reforms: 1920s-1930s
This document outlines significant educational reforms and the national situation in Chile during the 1920s and 1930s, highlighting key initiatives and their impact.
National Educational Landscape in 1931
- Child population: 781,376.
- School population: 452,208.
- Only 2% completed primary education (6 years).
- 73% completed only the first 3 years (out of a mandatory 4).
- 16% reached the 4th grade.
Further challenges included:
- Elementary Schools: 11% of schools in the country
Key Factors Behind Chile’s Independence
External Factors for Chilean Independence
1. American Independence (1776)
The American Independence in 1776 demonstrated the viability of a republican system of government. It introduced new political ideas such as representative democracy, citizens’ rights, popular sovereignty (the right to choose one’s government), and civil liberties.
2. The Enlightenment
According to Enlightenment principles, society and the state must be organized by reason, which guarantees freedom, security, and happiness. The
Read MoreKey Concepts in Texas Government and History
Traditionalist Political Culture
Supports the social and political status quo, resisting change.
Moralistic Political Culture
The belief that government should act in the best interest of everyone.
Individualistic Political Culture
Emphasizes the primacy of the individual in making decisions for their own life, promoting self-determination.
Estelle v. Ruiz (1976)
A landmark Supreme Court case where Texas was cited for having prison conditions that violated the Eighth Amendment.
Republic of Texas (1836-1845)
Read MoreArchaeologist’s Dream Quest: Unraveling Lichinga’s Ancient Mystery
An Archaeologist’s Premonition
Hello, my name is Will, and I am from New York. I am an archaeologist, and I normally dream about strange things, but this time was different. I woke up with a very strange sensation, my body shivering. Sometimes I explain my dreams to my wife, Susan, but this time she asked me about my appearance. Susan and I were talking in the kitchen during breakfast when the TV showed a program about a remote town in Africa. Suddenly, they began to display objects that I had dreamt
Read MoreEarly Christian Art & Architecture: Origins in the Roman Empire
Early Christian Art: Origins and Development
Early Christian art marks the genesis of a distinct typology of buildings and decorative arts within Western art history.
Historical Context of Early Christianity
Initially, Christianity had very few adherents and was prohibited within the Roman Empire. Originating in Palestine, particularly Bethlehem, the faith gradually expanded and gained followers. Despite severe persecutions against Christians during the 2nd and 3rd centuries AD, their numbers continued
Read MoreFoundations of Science and Technology: Key Discoveries and Thinkers
Understanding Science and Technology
Science is knowledge that depends on observation and experimentation, an attempt to understand nature. It is knowledge based on observation, the scientific method, and an ordering of knowledge of nature, forming an organizational system.
Types of Science
- Hard Science: Factual, stable, and undeniable. Examples include mathematics, physics, and chemistry. These fields lead to advancements like cars, televisions, and computers.
- Soft Science: Not always amenable to precise
TOEIC Exam Practice: Answer Keys for English Proficiency
TOEIC Model II Answer Key
Part 1: Multiple Choice Questions (1-40)
- 1-B
- 2-B
- 3-D
- 4-B
- 5-D
- 6-B
- 7-C
- 8-B
- 9-D
- 10-A
- 11-A
- 12-A
- 13-A
- 14-B
- 15-B
- 16-C
- 17-A
- 18-C
- 19-B
- 20-B
- 21-A
- 22-B
- 23-A
- 24-A
- 25-B
- 26-A
- 27-A
- 28-B
- 29-A
- 30-C
- 31-A
- 32-A
- 33-B
- 34-C
- 35-C
- 36-A
- 37-A
- 38-B
- 39-B
- 40-C
Part 2: Short Answer Questions (41-55)
- 41- In a supermarket
- 42- The location of a product
- 43- He will help the woman locate an item.
- 44- Attending a concert.
- 45- He finished an article.
- 46- At 8:00
- 47- At a resort
- 48- Lifeguard
- 49- Proof of certification
- 50- On Thursday
- 51- Biking
- 52- It is an interesting
English Verb Tenses Explained: Simple, Continuous, Perfect, and Future
Understanding English verb tenses is crucial for effective communication. This document breaks down the key tenses and their uses.
Simple Present
Used for habits, routines, true facts, permanent states, historical facts, and fixed schedules.
- Example: My grammar class starts at 4:00 PM.
Present Continuous
Used for actions happening now, temporary activities, and arrangements for the near future.
- Structure: Subject + verb-ing
- Example: He is playing the guitar.
- Example: I am looking for a flat.
- Example: I’m
Venezuela’s 1835 Revolution of Reform: Overthrowing Vargas
The 1835 Revolution of Reform: Overthrowing Vargas
Despite strong military opposition, Dr. Vargas was elected President of the Republic for the period 1835-1839. However, the warlords who had opposed his candidacy began to conspire against him. A military coup erupted in Caracas in July 1835, just five months after Dr. Vargas assumed the presidency. Key figures in this military movement, known as the ***Revolution of Reform***, included General Santiago Mariño (the defeated candidate), Diego Ibarra,
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