在R for循环和单个R图中创建的图形中的差异（图形）

Question

I have just written my first R script. I need to make numerous graphs for each item in a group and thought it would be quicker to loop through the items to create the pdfs. Using almost identical code, when I use the for loop, I have the info from the y-axis placed down the middle of the plot (bad). If I create one pdf at a time (sans loop), no text is placed down the middle of the plot (good). Could someone explain why there is a difference in the graphs between these two approaches and how to get rid of the centered text that occurs in the looped pdfs. Thank you in advance.

To create a single plot, I use the code below:

require(ggplot2)
require(reshape)
require(lattice)

header = scan('out_ordered.txt', nlines = 1, what = character())
header = header[3:length(header)]
data = read.table('out_ordered.txt', skip = 2, header = FALSE, row.names = 1)
names(data) = header
tdata = data.frame(t(data))
names(tdata)
pdf (file='Different.pdf')
plot(Bacteroidetes ~ Bacteroidetes, data = tdata, pch = 16, main = 'Bacteroidetes', xlab = 'Environment', ylab = 'Counts', axes = FALSE, las = 2)
original.parameters<-par()
par(xaxt='n')
lablist<-as.vector(c(header[1:length(header)]))
axis(1, at=1:length(header), labels = FALSE)
axis(2, at=0:63)
text(seq(1, length(header), by=1), par('usr')[3] - 0.2, labels = lablist, srt = 90, pos = 1, xpd = TRUE, offset = 2.5)
box()
dev.off()

There are some spacing issues with the labels on the x-axis and could in general use some buttons to express its flare, but it is on the right track.

If I use a loop, I used this code:

#!/usr/bin/Rscript 
 # change the working directory in R to the place where you have the input file.

require(ggplot2)
require(reshape)
require(lattice)

header = scan('out_ordered.txt', nlines = 1, what = character())
header = header[3:length(header)]
data = read.table('out_ordered.txt', skip = 2, header = FALSE, row.names = 1)
names(data) = header
tdata = data.frame(t(data))
names(tdata)

for(i in names(tdata))
{
        pdf(file = paste(i, '.pdf', sep = ''))
        plot(get(i) ~ get(i), data = tdata, pch = 16, main = get(i) , xlab = 'Environment', ylab = 'Counts', axes = FALSE, las = 2)
        original.parameters<-par()
        par(xaxt='n')
        lablist<-as.vector(c(header[1:length(header)]))
        lablist
        axis(1, at=1:length(header), labels = FALSE)
        axis(2, at=0:65)
        text(seq(1, length(header), by=1), par('usr')[3] - 0.2, labels = lablist, srt = 90, pos = 1, xpd = TRUE, offset = 2.5)
        box(which = 'plot')

        dev.off()
}

Here are the images:

The first image was one created in the looping process, the other as a standalone plot.

Answer 1

Probably not the most elegant and it did not answer my question...I removed the for-loop, created an array in bash of the items I wanted and looped through it - each time calling the R script with the array item as the R script argument. Not pretty -- but it works.

Answer 2

In the loop you have main = get(i) , which gets the values; that's why those numbers are showing up in the loop version. You instead want just main=i .