Obtaining R
The R&S®ZVA series is the high-end class of the Rohde & Schwarz network analyzers. It combines operating ease and high measurement speed uni-formly implemented in the R&S®ZVA, R&S®ZVB and R&S®ZVT with exceptional RF characteristics, a wide scope of functions and high flexibility. R&S®ZVA Vector Network Analyzer At a glance.
- R&S® ZVA-Z90E, Converter WR12, stock no. Observe all instructions and warnings provided in this manual. If you have any questions regarding these. If the necessary precautions are not taken, the user may suffer electric shock or the product.
- The Operating Manual also describes all options for the R&S®ZVA/ZVB/ZVT network analyzers. Additional Quick Start Guides provide basic information about accessories. They are also available for download on this website. Refer to the data sheet for additional information on the R&S®ZVA.
R is available for Linux, MacOS, and Windows. Software can be downloaded from The Comprehensive R Archive Network (CRAN).
Startup
After R is downloaded and installed, simply find and launch R from your Applications folder.
Entering Commands
R is a command line driven program. The user enters commands at the prompt (> by default) and each command is executed one at a time.
The Workspace
The workspace is your current R working environment and includes any user-defined objects (vectors, matrices, data frames, lists, functions). At the end of an R session, the user can save an image of the current workspace that is automatically reloaded the next time R is started.
Graphic User Interfaces
Aside from the built in R console, RStudio is the most popular R code editor, and it interfaces with R for Windows, MacOS, and Linux platforms.
Operators in R
R's binary and logical operators will look very familiar to programmers. Note that binary operators work on vectors and matrices as well as scalars.
Arithmetic Operators include:
Operator | Description |
+ | addition |
- | subtraction |
* | multiplication |
/ | division |
^ or ** | exponentiation |
Logical Operators include:
Operator | Description |
> | greater than |
>= | greater than or equal to |
exactly equal to | |
!= | not equal to |
Data Types
R has a wide variety of data types including scalars, vectors (numerical, character, logical), matrices, data frames, and lists.
Creating New Variables
Use the assignment operator <- to create new variables.
# An example of computing the mean with variables
mydata$sum <- mydata$x1 + mydata$x2
mydata$mean <- (mydata$x1 + mydata$x2)/2
Functions
Almost everything in R is done through functions. A function is a piece of code written to carry out a specified task; it may accept arguments or parameters (or not) and it may return one or more values (or not!). In R, a function is defined with the construct:
function ( arglist ) {body}
The code in between the curly braces is the body of the function. Note that by using built-in functions, the only thing you need to worry about is how to effectively communicate the correct input arguments (arglist) and manage the return value/s (if any).
Importing Data
Importing data into R is fairly simple. R offers options to import many file types, from CSVs to databases.
For example, this is how to import a CSV into R.
# first row contains variable names, comma is separator
# assign the variable id to row names
# note the / instead of on mswindows systems
mydata <- read.table('c:/mydata.csv', header=TRUE,
sep=',', row.names='id')
Descriptive Statistics
R provides a wide range of functions for obtaining summary statistics. One way to get descriptive statistics is to use the sapply( ) function with a specified summary statistic.
Below is how to get the mean with the sapply( ) function:
# get means for variables in data frame mydata
# excluding missing values
sapply(mydata, mean, na.rm=TRUE)
Possible functions used in sapply include mean, sd, var, min, max, median, range, and quantile.
R&b Music
Plotting in R
In R, graphs are typically created interactively. Here is an example:
# Creating a Graph
attach(mtcars)
plot(wt, mpg)
abline(lm(mpg~wt))
title('Regression of MPG on Weight')
The plot( ) function opens a graph window and plots weight vs. miles per gallon. The next line of code adds a regression line to this graph. The final line adds a title.
Packages
Packages are collections of R functions, data, and compiled code in a well-defined format. The directory where packages are stored is called the library. R comes with a standard set of packages. Others are available for download and installation. Once installed, they have to be loaded into the session to be used.
.libPaths() # get library location
library() # see all packages installed
search() # see packages currently loaded
Getting Help
Once R is installed, there is a comprehensive built-in help system. At the program's command prompt you can use any of the following:
R&l Carriers
help.start() # general help
help(foo) # help about function foo
?foo # same thing
apropos('foo') # list all functions containing string foo
example(foo) # show an example of function foo
Going Further
If you prefer an online interactive environment to learn R, this free R tutorial by DataCamp is a great way to get started.
Also found in: Dictionary, Medical, Financial, Wikipedia.
Acronym | Definition |
---|---|
R&R | Rock and Roll (music) |
R&R | Rest & Relaxation |
R&R | Rules and Regulations |
R&R | Resource and Referral |
R&R | Read and Review |
R&R | Rum and Raspberry (drink) |
R&R | Rate and Review |
R&R | Rescue & Recovery |
R&R | Rest and Recuperation |
R&R | Read & Review |
R&R | Reverse and Repeat |
R&R | Radio & Records, Inc |
R&R | Romney and Ryan (political shorthand) |
R&R | Repeatability and Reproducibility |
R&R | Rescue and Recovery |
R&R | Repair and Return |
R&R | Removal and Reinstallation |
R&R | Recruitment & Retention (human resources) |
R&R | Relief and Rehabilitation |
R&R | Revise & Resubmit (publishing) |
R&R | Resettlement and Rehabilitation (India) |
R&R | Rendezvous and Recovery (spacecraft) |
R&R | Remove & Replace |
R&R | Repair and Replace |
R&R | Reward and Recognition (human resources) |
R&R | Refuse & Resist! (non-partisan, national membership organization) |
R&R | Run and Rate (process assessment) |
R&R | Remove and Reinstall (computer software) |
R&R | Repairs and Restoration (various organizations) |
R&R | Rest & Recreation |
R&R | Rest & Recuperation |
R&R | Response & Recovery (FEMA) |
R&R | Retention and Release (NASA) |
R&R | Repair & Return |
R&R | Repeatability and Reliability (statistical analysis) |
R&R | Roles and Responsibility |
R&R | Read & Relax |
R&R | Refit and Repair |
R&R | Refuse Routine |
R&R | Rock and Rye (bar drink) |
R&R | Receiving and Release (prisons) |
R&R | Repair & Renewal |
R&R | Research & Reconnaissance |
R&R | Rest & Romance |
R&R | Review and Revalidation |
R&R | Removal and Reassembly |
R&R | Rebutted and Rejointed (roofing shingles) |
R&R | Reefer & Relaxation |
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