data visualization - How to combine different barplot in R? -

i new r user.

i have difficult time figuring out how combine different barplot 1 graph.

for example,

suppose, top 5 of professions in china, are, government employees, ceos, doctors, athletes, artists, incomes (in dollars) respectively, 20,000,17,000,15,000,14,000,and 13,000, while top 5 of professions in us, are, doctors, athletes, artists, lawyers, teachers incomes (in dollars) respectively, 40,000,35,000,30,000,25,000 , 20,000.

i want show differences in 1 graph.

how supposed that? beware have different names.

the answer question straight forward. new r user, recommend make liberal use of 'ggplot2' package. many r users, 1 package enough.

to "combined" barchart described in original post, answer put of data 1 dataset , add grouping variables, so:

step 1: make dataset.

data <- read.table(text=" country,profession,income china,government employee,20000 china,ceo,17000 china,doctor,15000 china,athlete,14000 china,artist,13000 usa,doctor,40000 usa,athlete,35000 usa,artist,30000 usa,lawyer,25000 usa,teacher,20000", header=true, sep=",") 

you'll notice i'm using 'read.table' function here. not required , purely readability in example. important part have our values (income) , our grouping variables (country, profession).

step 2: create barchart income height of bars, profession x-axis, , color bars country.

library(ggplot2)  ggplot(data, aes(x=profession, y=income, fill=country)) +     geom_bar(stat="identity", position="dodge") +     theme(axis.text.x = element_text(angle = 90)) 

here first loading 'ggplot2' package. may need install this.

then, specify data want use , how separate it.

ggplot(data, aes(x=profession, y=income, fill=country)) 

this tells 'ggplot' use our dataset in 'data' data frame. aes() command specifies how 'ggplot' should read data. map grouping variable income onto x-axis, map income onto y-axis, , change color (fill) of each bar according grouping variable country.

next, specify kind of barchart want.

geom_bar(stat="identity", position="dodge") 

this tells 'ggplot' make barchart (geom_bar()). default, 'geom_bar' function tries make histogram, have totals want use. tell use our totals specifying type of statistic represented in income total, or actual values (identity) want chart (stat="identity"). finally, made judgement call how display data , decided set 1 set of data on next other when single profession has multiple income values (position="dodge").

finally, need rotate x-axis labels, since of them quite long. simple 'theme' command changes rotation of x-axis text elements.

theme(axis.text.x = element_text(angle = 90)) 

we chain of these commands +, , it's done!