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# Topic 1: FIRST STEPS #
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rm(list=ls())# clean all objects in memory
setwd ('D:/Data Lab/Data Vianney/Class/R ecology/Class 2017-2018/data_class') # set up new wd

# UPDATE
if(!require(installr)) {
  install.packages("installr"); require(installr)} 
updateR()

# PACKAGE
install.packages ("abc") # install the package 'abc'
library ("abc") # load the package 'abc'

# HELP
? median
help (median) # help on median function
median # basic use of the function	
?? median # help on all function with median in the description

# WORKING DIRECTORY
getwd() # identify your current working directory
?setwd # set up a new working directory

# QUIT R
# q() # to quit R

# OBJECTS
ls() # all objects in memory
rm(list=ls()) # clean all objects in memory
# press CTRL +L to clean all your console


# CALCULATOR
3+2 # addition
3-2 # substraction
3*2 # multiplication
3/2 # division
3^3 # power
log(2) # logarithm
exp(2) # exponential
(5 + 3) / 4 # define priority using () or {} 
pi*4 # common function

# READING DATA
setwd ('D:/.../')
# setwd ('D:/Data Lab/Data Vianney/Class/R ecology/Rclass/dataset')
read.table ("taiwan_coral.txt",header = TRUE,sep="\t", dec=".")
# same as following if we are not changing the working directory
read.table ("D:/.../taiwan_coral.txt",header = T, 	sep="\t", dec=".")
# also same as:
read.table("taiwan_coral.txt", TRUE, "\t",".")
# create and name object
taiwan_coral <- read.table ("taiwan_coral.txt", 	header = TRUE, sep="\t", dec=".")
taiwan_coral

# you can locate the file by hand
dat <- read.table (file.choose (), 	header = T, sep="\t", dec=".")

# you can also use read.delim(), read.csv(), and others functions

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# END #
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