Rrrrrr…… now we know what it is but how the heck do you use it? Andrew Trant PPS Arctic - Labrador Highlands Research Group
Jan 23, 2016
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