[R] how to control ticks in plots with yasp or xasp

[Denis Chabot]

Oops, Mark, bad typo indeed.

But yaxp is what I had in my R program and it did not help.

I did obtain control over my tick marks by drawing them myself, as  
you suggest. But I was curious as to how to use yaxp since the help  
on "par" gives it as a possible way of controlling ticks. Maybe it  
should be removed from the help file?

Thanks for your help,

Denis
Le 05-10-08 à 11:16, Marc Schwartz a écrit :

> On Sat, 2005-10-08 at 09:28 -0400, Denis Chabot wrote:
>
>> Hi,
>>
>> A few times I tried to control the number and position of tick marks
>> in plots with the yasp or xasp parameters. For example, a y axis was
>> drawn by default with tick marks at 0, 20, 40, 80 and 100. I tried to
>> get tick marks every 10 by adding
>>
>> yasp=(0, 100, 10)
>>
>> but this had no effect at all. I know I can draw the axis and tick
>> marks manually, but often this simple option would suffice if I could
>> understand how to make it work.
>>
>> Thanks in advance,
>>
>> Denis Chabot
>>
>
>
> I suspect that one problem you are having is that there is no
> par("xasp") or par("yasp")....unless these are typos and you are  
> trying
> to use par("xaxp") and par("yaxp")?
>
> There is an 'asp' argument to some of the plot functions (ie.
> plot.default), but this has a different intention.
>
> par("xaxp") and par("yaxp") are not listed as read only pars in ?par,
> however, I cannot recall an instance where R does not overwrite the  
> user
> settings during the calculation of the axes, whether passed as  
> arguments
> to a plot function or set a priori via a par() call.
>
> If you want explicit control over the tick marks, you will need to use
> axis(), perhaps in combination with axTicks(), after using 'xaxt =  
> "n"'
> and/or 'yaxt = "n"' in the plot call, depending upon the  
> circumstances.
>
> HTH,
>
> Marc Schwartz
>
>
>