Rrrrrr……now we know what it is but how the heck do

you use it?

Andrew Trant

PPS Arctic - Labrador Highlands Research Group

I) get data

II) get data organized and formatted

III) import data

First things first

I) get data

II) get data organized and formatted

III) import data

First things first

Save as .csv file

I) get data

II) get data organized and formatted

III) import data

First things first

Importing data into R

-open R and save workspace as test.Rdata #make sure you save workspace image

-go into data folder and open ‘test.Rdata’>read.csv(“ReefFishAbundance.csv”)

REMEMBER: nothing is saved into the workspace environment unless you assign it a name

>fish<-read.csv(“ReefFishAbundance.csv”)

‘R’udimentarySome things to try:

>ls() ……………………………… Lists objects>names(fish) ………….………. Lists variables>junk<-fish ……..….………..… Rename >summary(fish) ………….…… Descriptive stats >ls()>rm(junk) ……………………... Removes from ls()>rm(list=ls()) …………………. Clears workspace PERMANENTLY

‘R’ows then columnsManipulating data.frame:

>fish[1,2] …………... row 1, column 2

>fish[1:3,5] ………… rows 1,2,3 column 5

>fish[1,c(3,5:6)] ……. row 1 columns 3,5,6

>fish[1,-c(5:6)] …….. row 1 and NOT columns 5,6

c = combine

‘R’ussian dolls

Subsetting data:

>subset(fish,year==1) ……….…….. equal to 1

>subset(fish,year!=1) ……………… NOT equal 1

>subset(subset(fish,year==2),N>170)

Tables From dataset airquality (preloaded):

>airquality #confusing

>with(airquality,table(Temp,Month)) #better

>with(airquality, table(cut(Temp, quantile(Temp)), Month)) #best

#’quantile’ breaks Temp range into 4 equal parts

Mo’R’e Tables >airtable<-with(airquality,table(cut(Temp,quantile(Temp)),Month))

>margin.table(airtable)>margin.table(airtable,1) #sum by rows>margin.table(airtable,2) #sum by columns

>prop.table(airtable)>prop.table(airtable,1) #prop by row>prop.table(airtable,2) #prop by column

>summary(airtable) #Chi-squared test

Conspi’R’ing (or plotting)

Low level: plot, hist, barplot….

High level: xyplot, dotplot, densityplot, contour, cloud

from packages, must install ‘LATTICE’

examples:

>with(fish,plot(N~transect,xlab=“transect #”, ylab=“N”))

>bwplot(voice.part ~ height, data=singer, xlab="Height (inches)")

>contour

Saving you’R’ plot

Plot something example:>bwplot(voice.part ~ height, data=singer, xlab="Height”)

Make it the active window (ie. click on it)

You’R’ own function

>testplot<-function(){}

>fix(testplot)>function(){with(fish,plot(N~transect))}

to execute the function:>testplot()

to review your function:>testplot

‘R’ecap

-Find, organize, import data-Manipulate, subset-Make tables-Generate plots and save plots-Make yer very own function

WHAT ELSE IS THERE?

Shutting down

I) Save history fileexample: oct19.History

II) Save workspace fileexample: test.Rdata

III) Close the window and save workspace image