R help - Jul 2008 - creating axis of the plot before data are plotted

Dear R-users,

I'm tackling with a problem which causing me a head-ache for a long time. I
would like to create a nice x-axis to my plots, but I do not know how to
implement the method.

Imagine a matrix where you have rownames real numbers -- these rownames
should be written in the x-axis nicely. I could not find any way how.

I'll describe what I'm doing now:
I have a matrix where each column is an independent curve (number of the
columns 3-4). The rownames are the x-axis, and the names are real numbers
(converted to chars, of course). I find the max and the min among the values
in the matrix (for the y-axis) and I'm creating an empty plot. x-axis is
c(0, nrow(matrix)). Now, I'm creating the x-axis labels

Labels <- seq(1, nrow(matrix), by = 100)
axis(1, at = NULL, labels = rownames(matrix)[Labels])

At this point I'd like to have instead of "24.12333    26.45667   
28.79
31.12333    33.45667" at the x-axis, an optimally placed ticks at let's
say
"26 28 30 32" -- this is what I cannot achieve.

Afterwards I'm plotting the curves in different colours. I know that the
x-values are accessed by the number of their row and not rowname.

Anybody could point me into some direction, please? Thank you upfront!

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try at=seq(from=26, to=32, by=2) in the axis statment
hope this helps

Stephen

On Mon, Jul 14, 2008 at 11:21 AM, Zroutik Zroutik <zroutik@gmail.com>
wrote:
> Dear R-users,
>
> I'm tackling with a problem which causing me a head-ache for a long
time. I
> would like to create a nice x-axis to my plots, but I do not know how to
> implement the method.
>
> Imagine a matrix where you have rownames real numbers -- these rownames
> should be written in the x-axis nicely. I could not find any way how.
>
> I'll describe what I'm doing now:
> I have a matrix where each column is an independent curve (number of the
> columns 3-4). The rownames are the x-axis, and the names are real numbers
> (converted to chars, of course). I find the max and the min among the
> values
> in the matrix (for the y-axis) and I'm creating an empty plot. x-axis
is
> c(0, nrow(matrix)). Now, I'm creating the x-axis labels
>
> Labels <- seq(1, nrow(matrix), by = 100)
> axis(1, at = NULL, labels = rownames(matrix)[Labels])
>
> At this point I'd like to have instead of "24.12333    26.45667   
28.79
> 31.12333    33.45667" at the x-axis, an optimally placed ticks at
let's say
> "26 28 30 32" -- this is what I cannot achieve.
>
> Afterwards I'm plotting the curves in different colours. I know that
the
> x-values are accessed by the number of their row and not rowname.
>
> Anybody could point me into some direction, please? Thank you upfront!
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Let's not spend our time and resources thinking about things that are so
little or so large that all they really do for us is puff us up and make us
feel like gods. We are mammals, and have not exhausted the annoying little
problems of being mammals.

-K. Mullis

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