wibeasley

This post examines the features of [R Markdown](http://www.rstudio.org/docs/authoring/using_markdown) 
using [knitr](http://yihui.name/knitr/) in Rstudio 0.96.
This combination of tools provides an exciting improvement in usability for 
[reproducible analysis](http://stats.stackexchange.com/a/15006/183).
Specifically, this post 
(1) discusses getting started with R Markdown and `knitr` in  RStudio 0.96;
(2) provides a basic example of producing console output and plots using R Markdown;
(3) highlights several code chunk options such as caching and controlling how input and output is displayed;
(4) demonstrates use of standard Markdown notation as well as the extended features of formulas and tables; and 
(5) discusses the implications of R Markdown.

wibeasley

library(tidyverse)
library(DBI)
library(odbc)


# connect to database
cn <- dbConnect(odbc::odbc(), driver = "ODBC Driver 13 for SQL Server", 
                server="MYSQLSERVER\\SQLEXPRESS", 
                database = "myTestDB",
                Trusted_Connection="Yes")

wibeasley

#'  This code checks the user's installed packages against the packages listed in
#'    https://github.com/OuhscBbmc/RedcapExamplesAndPatterns/blob/master/utility/package-dependency-list.csv
#'    These packages are necessary for most of the analyses run by the OUHSC BBMC  (https://github.com/OuhscBbmc).
#'
#'  CRAN packages are installed only if they're not already; then they're updated if available.
#'     GitHub packages are installed regardless if they're already installed.
#'
#'  If anyone encounters a package that should be on there, please add it to
#'   https://github.com/OuhscBbmc/RedcapExamplesAndPatterns/blob/master/utility/package-dependency-list.csv
#'

wibeasley

f1 <- function(x) (3*x - 40) / 10
f2 <- function(x) (-20 - 2*x) / 2

# f1 <- function(x) (24000 - 200*x) / 350
# f2 <- function(x) (130 - x) / 2
x_limits  <- c(-10, 100)

########## Don't change anything below this line #########################
g <- function(x) f1(x) - f2(x)
y_range     <- range(0, f1(x_limits), f2(x_limits))