[Rd] using rasterImage within image

[Henrik Bengtsson]

On Wed, Feb 9, 2011 at 11:53 AM, Simon Urbanek
<simon.urbanek at r-project.org> wrote:
>
> On Feb 9, 2011, at 2:36 PM, Henrik Bengtsson wrote:
>
>> On Wed, Feb 9, 2011 at 11:25 AM, Simon Urbanek
>> <simon.urbanek at r-project.org> wrote:
>>> Ben,
>>>
>>> I have committed something analogous to R-devel (your rotation code was not unlike mine, I replicated the color handling from R internals to be consistent, I fixed the drawing limits and added a check for x/y conformance). Note that useRaster can only be used when x, y form a regular grid. Although I tried a lot of corner cases (requiring quite a few fixes), I'm sure I did not test all of them, so volunteers please give it a go and compare it with non-raster output.
>>>
>>> The only thing I'm not quite happy about is the argument name: useRaster. Personally, I hate camel case in R (it has crept in more recently making it horribly inconsistent) so please feel free to suggest a better name ;).
>>
>> It.is.spelled.camelCase.
>>
>
> Fortunately not in English ;)
>
>
>> What about style=c("image", "raster")?  This allows for future extensions too.
>>
>
> Hmm.. it's not really a "style" - the output doesn't change (ideally) - it's more of a back-end specification .. also we already have oldstyle argument in image() adding to the confusion ...

flavor=c("image", "raster")
renderer=c("image", "raster")
backend=c("image", "raster")
...

?

/H

>
> Thanks,
> Simon
>
>
>>>
>>> Thanks,
>>> Simon
>>>
>>>
>>> On Feb 9, 2011, at 10:06 AM, Ben Bolker wrote:
>>>
>>>> On 11-02-08 10:03 PM, Simon Urbanek wrote:
>>>>> Ben,
>>>>>
>>>>> did you actually look at the result of your function with useRaster=TRUE ? ;) [Hint: don't use an image that is symmetric]
>>>>>
>>>>> Apart from that nice bug there are more issues as well, try
>>>>> image(matrix(1:4,2),col=1:3)
>>>>> The underlying issue is that as.raster() is not quite what you would hope.
>>>>> Unfortunately I'm not aware of an easy fix (that doesn't involve going
>>>> back to RGB decomposition).
>>>>>
>>>>> In general, I think it's a nice option, but I don't think you'll get away with only a few lines...
>>>>>
>>>>> Cheers,
>>>>> Simon
>>>>>
>>>>>
>>>>>
>>>>> On Feb 8, 2011, at 8:49 PM, Ben Bolker wrote:
>>>>>
>>>>>>
>>>>>> Has anyone yet tried incorporating rasterImage into the base image()
>>>>>> function?  It seems to make a *huge* difference, with
>>>>>> a very small number of added/changed lines of code.  (Of course I have
>>>>>> barely tested it at all.)
>>>>>> Is there any reason this *shouldn't* go into the next release?
>>>>>>
>>>>>>> source("image.R")
>>>>>>> z <- matrix(runif(1e6),nrow=1000)
>>>>>>> image(z)
>>>>>>> image(z,useRaster=TRUE)
>>>>>>
>>>>>> (Patch against SVN 54284 attached; people can contact me if it doesn't
>>>>>> go through and they want it.)
>>>>>>
>>>>>> Ben Bolker
>>>>>>
>>>>>> <image_diff.txt>______________________________________________
>>>>>> R-devel at r-project.org mailing list
>>>>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>>
>>>>  Trying again. Rotated counterclockwise within R (although this *could*
>>>> be coded in C if speed were important?)
>>>>  Some brute-force testing suggests it is *slightly* slower for small
>>>> images (7 vs 8 seconds for 1000 reps) and still much faster (and
>>>> produces much smaller images, which don't suffer from antialiasing junk
>>>> in my PDF viewer) for large images.
>>>> <image_diff.txt><imagetest.R><image.R>
>>>
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>
>>
>
>