[R] x axis

[David L Carlson]

There are lots of options since you did not tell us what you want on the
axis (or what you have tried).

For example if you want more than 6 tick marks/labels, replace xlim=c(0,
3000) with xaxp=c(0, 3000, 12) to get labels every 250 meters instead of
500. Depending on the size of the graph window you may need to add
cex.axis=.8 to reduce the text size to fit the labels in the available
space. Likewise xaxp=c(0, 3000, 3) would reduce the number of labels to
every 1000 meters.


-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On
Behalf Of R. Michael Weylandt
Sent: Thursday, October 13, 2011 1:17 PM
To: lauren mcdonagh
Cc: r-help at r-project.org
Subject: Re: [R] x axis

In your plot call, you can use xaxt = "n" to turn off the default x
axis tick marks, then add

axis(1, at  = VARIABLEWHEREYOUWANTTICKMARKS) # If you want ticks at
the x you put in, its just axis(1, at = x)

to get ticks where you want them. There's also a label= argument if
you want them to be labled as something other than the numbers.

Hope this helps,

Michael

On Thu, Oct 13, 2011 at 11:42 AM, lauren mcdonagh
<cleverlollipop at yahoo.ie> wrote:
> Dear R users,
>
> I am quite desperate for help. I haven't used R in a couple of years and
I'm currently finishing a masters project and running out of time to figure
out my problem. I have read and tried the examples on many websites, in your
forums and R Help yet still can't manage to change the x axis. I am using R
2.8.0 on windows.
>
> I'm sure there must be a way to do this as many people's questions seem
more difficult. My problem is that I need to change the numbers on the x
axis from the default.
>
> This is my scatter plot so far:
>
>
>> x <- c(0, 50, 100, 250, 500, 750, 1000, 1500, 2000, 2500, 3000)
>> y <- c(640, 585, 152, 85, 348, 922, 518, 82, 83, 591, 79)
>> plot(y~x, type = "p", xlab = "Distance (m)", ylab = "Concentrations
(mg/kg)", xlim = c(0,3000), ylim = c(0,1000), col ="black", pch = 19, sub =
"Lead", font.sub = 2)
>> text(0,640, "mine average", pos = 4, col = "red", cex= 0.6)
>> abline(h=c(21), lty = 2, col = "green", lwd =1)
>> abline(h=c(36), lty = 3, col = "blue", lwd = 1)
>> abline(h=c(190), lty = 1, col ="red", lwd = 2)
>> legend(1700, 1000, c("Control", "Dutch List - Optimum", "Dutch List -
Action"), col = c(3,4,2), lty = c(2,3,1), cex = 0.8, lwd = c(1,1,2))
>
> R automatically changes the x axis to 0, 500, 100, 1500, 2000, 2500, 3000.
I've tried a few things you've already said to other people with problems
but all I get is error.
>
> I would really appreciate some help as I've no one else to ask (the uni
I've studied my masters in does not use R).
>
> Yours faithfully,
>
> Lauren.
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
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http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>

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