14. 워드 출현빈도 그래프로 나타내기 Plotting Word Frequencies
sort() 를 이용하여 해당 corpus 내 모든 단어들의 빈도를 카운트할 수 있다.
> freq <- sort(colSums(as.matrix(dtm)), decreasing=TRUE) // colSums : computing the sums of matrix columns
// as.matrix : explicitly converting from data frame to matrix
> head(freq,14)
the and that you have will this but draft
71 56 51 27 15 15 13 11 11
about all strickland: for know
10 10 9 8 8
> wf <- data.frame(word=names(freq), freq=freq) // names() : get or set the names of an object
> head(wf)
word freq
the the 71
and and 56
that that 51
you you 27
have have 15
will will 15
> library(ggplot2)
Attaching package: ‘ggplot2’
The following object is masked from ‘package:NLP’:
annotate
> p <- ggplot(subset(wf, freq>10), aes(word, freq)) // 빈도 10 이상, x축 = word, y축 = freq
> p <- p + geom_bar(stat="identity") // geom_bar : producing 1d area plots, stat="identity" : turn off the default summary
> p <- p + theme(axis.text.x=element_text(angle=45, hjust=1))
> p
>