[R] Using metric units in plots

[Duncan Murdoch]

On 20/06/2008 6:41 AM, Philip Rhoades wrote:
> Prof Brian Ripley,
> 
> 
> Prof Brian Ripley wrote:
>> On Fri, 20 Jun 2008, Philip Rhoades wrote:
>>
>>> People,
>>>
>>> It appears that one has to use Imperial measurements in plot 
>>> parameters?  I can't find any info on using metric units . .
>> In package grid you can use several different units.
> 
> 
> When I search the R site for "grid" I get:
> 
> "Package ‘grid’ was removed from the CRAN repository"

That's because it became a base package.  It's distributed with R, not 
as a separate package on CRAN.
> 
> 
>> In base graphics there are a very few par()s that use inches (and I am 
>> pretty sure that comes from the US unit as used in S, not the 'Imperial' 
>> one -- see e.g. Wikipedia).  But those are rarely used.
> 
> 
> This is a bit confusing - as far as I can see, ALL the pars use inches? 
> I understand the US effect but shouldn't Metric units be supported directly?

I believe only inches are used as physical units, but many of the par() 
values don't use physical units.  There are lines, user coordinates, 
etc.  And plot() makes almost no use of physical units.

Duncan Murdoch

> 
> 
>> Also most graphics devices are dimensioned in inches with resolutions in 
>> dpi.
>>
>> Function cm() might help you.
> 
> 
> Thanks,
> 
> Phil.