Study statistical programming

Author: XuhuaHuang

R/README.md

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+# Statistical Programming
+
+## Setup: Installing R and Tools
+
+```r
+install.packages("ggplot2")
+```
+
+## Statistical Computing
+- Statistics → modeling, inference, probability
+- Computer Science → algorithms, efficiency
+- Data → storage, processing, transformation
+- Programming → automation and reproducibility
+- Graphics → visualization and communication
+- Simulation → e.g., Monte Carlo methods
+
+Statistical computing is the use of computational methods to perform statistical analysis, simulation, and data visualization.
+
+## Main Components of Statistical Computing
+
+1. Data Manipulation
+```r
+subset(cars, speed > 10)
+```
+2. Programming
+```r
+square <- function(x) {
+  x^2
+}
+```
+3. Graphics
+```r
+plot(cars)
+```
+
+## Object-Oriented Nature of `R`
+```r
+class(cars)
+summary(cars)
+plot(cars)
+
+```
+- Regression Example
+```r
+out <- lm(dist ~ speed, data = cars)
+class(out)
+summary(out)
+plot(out)
+```
+
+## Command Line Options and Helps
+- `-save` or `-no-save`
+- `-restore` or `-no-restore`
+
+```r
+help(search)
+```
+
+## Syntax and Grammar
+
+A complete expression is any typed expression that falls into one of the following seven classes:
+
+- Literals
+- Calls
+- Assignments
+- Conditionals: comparison, logical
+- Loops
+- Control flow statements
+- Grouping statements
+
+## R Sessions
+`setwd` and `getwd`
+
+Use `?Syntax` to find operator syntax
+
+If unsure of operator precedence, use parentheses.
+
+## R Objects
+
+All objects created in command line (`RStudio` calls it console) are saved
+in `.GlobalEnv`.
+
+`R` treats everything as an object
+- data objects
+- function objects
+- list objects
+- `NULL` objects
+- `...` object
+- language objects
+- symbol objects
+- expression objects
+
+```r
+ls()
+objects()
+ls.str()
+find("lm")
+help.search("lm")
+rm(x)
+rm(x, y, z)
+rm(list = ls())
+```
+
+### Class, Type of Length of an Object
+```r
+class(cars)
+typeof(cars)
+length(cars)
+attributes(cars)
+names(cars)
+dim(cars)
+```