use expression() in a loop

Hi all,

I want to do plot() in a loop to make 10 graphs, so I have some code like

for (i in 1:10) {
   plot(... ... , xlab = expression(g[i]) )
}

I expect g_1, g_2, and so on appear on x labels, but it simply prints
g_i for each graph. Does anybody know how to get around this problem?
Thanks.

NL

Hi all,

I want to do plot() in a loop to make 10 graphs, so I have some code like

for (i in 1:10) {
   plot(... ... , xlab = expression(g[i]) )
}

I expect g_1, g_2, and so on appear on x labels, but it simply prints
g_i for each graph. Does anybody know how to get around this problem?
Thanks.

NL

on 08/18/2008 05:00 PM Nanye Long wrote:

Hi all,

I want to do plot() in a loop to make 10 graphs, so I have some code like

for (i in 1:10) {
   plot(... ... , xlab = expression(g[i]) )
}

I expect g_1, g_2, and so on appear on x labels, but it simply prints
g_i for each graph. Does anybody know how to get around this problem?
Thanks.

NL

Try this:

par(mfrow = c(5, 2))

for (i in 1:10)
 plot(1, xlab = bquote(g[.(i)]))


Note the use of bquote() and the use of .(i), which replaces 'i' with
the value of i in each iteration.

See ?plotmath for some examples and ?bquote

HTH,

Marc Schwartz

x <- c(1,2,3,4,5,6)
paste(paste(x[seq(1, by=2, length=length(x)/2)], x[seq(2, by=2, length=length(x)/2)]), collapse="\n")

Dear R-helpers,

I have a numeric vector, like:

x <- c(1,2,3,4,5,6)

I make this into a string for output to a text file, separated by \n:

paste(x, collapse="\n")

Is there a way to alternate the collapse argument? So between the first two elements of x, I want to separate by " ", then by "\n", and so forth.
The result should then look like:
"1 2\n3 4\n5 6"

(This way I get 2 elements of x on each line using writeLines, instead of one or all).
I could do this in some ugly loop, but surely there is a better way?

thanks,
Remko

From: remko duursma <remkoduursma at hotmail.com>
Subject: [R] paste: multiple collapse arguments?
To: r-help at r-project.org
Received: Tuesday, 26 August, 2008, 9:36 AM
Dear R-helpers,

I have a numeric vector, like:

x <- c(1,2,3,4,5,6)

I make this into a string for output to a text file,
separated by \n:

paste(x, collapse="\n")

Is there a way to alternate the collapse argument? So
between the first two elements of x, I want to separate by
" ", then by "\n", and so forth.
The result should then look like:
"1 2\n3 4\n5 6"

(This way I get 2 elements of x on each line using
writeLines, instead of one or all).
I could do this in some ugly loop, but surely there is a
better way?

thanks,
Remko

paste(paste(x, c(" ","\n"), sep=""), collapse="")

-----Original Message-----
From: r-help-bounces at r-project.org 
[mailto:r-help-bounces at r-project.org] On Behalf Of remko duursma
Sent: Monday, August 25, 2008 7:37 PM
To: r-help at r-project.org
Subject: [R] paste: multiple collapse arguments?


Dear R-helpers,

I have a numeric vector, like:

x <- c(1,2,3,4,5,6)

I make this into a string for output to a text file, separated by \n:

paste(x, collapse="\n")

Is there a way to alternate the collapse argument? So between 
the first two elements of x, I want to separate by " ", then 
by "\n", and so forth.
The result should then look like:
"1 2\n3 4\n5 6"

(This way I get 2 elements of x on each line using 
writeLines, instead of one or all).
I could do this in some ugly loop, but surely there is a better way?

thanks,
Remko

Dear R-helpers,

I have a numeric vector, like:

x <- c(1,2,3,4,5,6)

I make this into a string for output to a text file, separated by \n:

paste(x, collapse="\n")

Is there a way to alternate the collapse argument? So between the first two elements of x, I want to separate by " ", then by "\n", and so forth.
The result should then look like:
"1 2\n3 4\n5 6"

(This way I get 2 elements of x on each line using writeLines, instead of one or all).
I could do this in some ugly loop, but surely there is a better way?

thanks,
Remko