[Bioc-devel] Changes to the SummarizedExperiment Class

Kasper Daniel Hansen kasperdanielhansen at gmail.com
Mon Mar 9 15:06:29 CET 2015


It sounds like the proposed changes are already made.  However (like
others) I am still a bit mystified why this was necessary.  The old version
did allow for a GRanges inside the DataFrame of the rowData, as far as I
recall.  So I assume this is for efficiency.  But why?  What kind of
data/use cases is this for?

I am happy to hear that SummarizedExperiment is going to be spun out into
its own package.  When that happens, I have some comments, which I'll
include here in anticipation
  1) I now very strongly believe it was a design mistake to not have
colnames on the assays.  The advantage of this choice is that sampleNames
are only stored one place.  The extreme disadvantage is the high
ineffeciency when you want colnames on an extracted assay.
  2) I still strongly believe we should support pData, sampleNames etc etc
on SummarizedExperiments.
  3) Having developed a package (minfi) where eSets co-exists with
SummarizedExperiment, I have to mention that for the developer there is a
number of places where the different internals of these two classes makes
like irritating.  For this reason I would support a "modern" implementation
of eSet, in parallel with SummarizedExperiment.

Best,
Kasper

On Fri, Mar 6, 2015 at 10:59 AM, Valerie Obenchain <vobencha at fredhutch.org>
wrote:

> Hi Mike,
>
> Our error - we didn't bump GenomicRanges when rowRanges was added.
> Hopefully 1.19.43 will propagate today and things will be sorted out.
>
> Val
>
>
> On 03/06/2015 07:40 AM, Michael Love wrote:
>
>> hi all,
>>
>> just a practical issue: I have GenomicRanges version 1.19.42 on my
>> computer which does not have rowRanges defined, although the 1.19.42
>> version on the Bioc website does have rowRanges in the man page:
>>
>> http://master.bioconductor.org/packages/3.1/bioc/html/GenomicRanges.html
>>
>> So I pass check locally but not in the devel branch on Bioc servers.
>>
>>  library(GenomicRanges)
>>> rowRanges
>>>
>> Error: object 'rowRanges' not found
>>
>>> sessionInfo()
>>>
>> R Under development (unstable) (2014-12-08 r67137)
>> Platform: x86_64-apple-darwin12.5.0 (64-bit)
>>
>> locale:
>> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>>
>> attached base packages:
>> [1] stats4    parallel  stats     graphics  grDevices datasets  utils
>>     methods   base
>>
>> other attached packages:
>> [1] GenomicRanges_1.19.42 GenomeInfoDb_1.3.13   IRanges_2.1.41
>> S4Vectors_0.5.21
>> [5] BiocGenerics_0.13.6   RUnit_0.4.28          devtools_1.7.0
>> knitr_1.9
>> [9] BiocInstaller_1.17.5
>>
>>
>>
>> On Wed, Mar 4, 2015 at 3:03 PM, Martin Morgan <mtmorgan at fredhutch.org>
>> wrote:
>>
>>>
>>> On 03/04/2015 10:03 AM, Peter Haverty wrote:
>>>
>>>>
>>>> Michael has a good point. The complexity of the BioC universe of classes
>>>> hurts our ability to attract new users. More classes would be a minus
>>>> there
>>>> ... but a small set of common, explicit APIs would simplify things.
>>>> Rectangular things implement the matrix Interface.  :-) Deprecating old
>>>> stuff, like eSet, might help more than it hurts, on the simplicity
>>>> front.
>>>>
>>>> P.S. apropos of understanding this universe of classes, I *love* the
>>>> methods(class=x) thing Vincent mentioned.
>>>>
>>>
>>>
>>> The current version, under R-devel, is at
>>>
>>>    devtools::source_gist("https://gist.github.com/mtmorgan/
>>> 9f98871adb9f0c1891a4")
>>>
>>>    > methods(class="SummarizedExperiment")
>>>     [1] [                 [[                [[<-              [<-
>>>     [5] $                 $<-               assay             assay<-
>>>     [9] assayNames        assayNames<-      assays            assays<-
>>>    [13] cbind             coerce            colData           colData<-
>>>    [17] compare           Compare           countOverlaps     coverage
>>>    [21] dim               dimnames          dimnames<-
>>> disjointBins
>>>    [25] distance          distanceToNearest duplicated
>>> elementMetadata
>>>    [29] elementMetadata<- end               end<-             exptData
>>>    [33] exptData<-        extractROWS       findOverlaps      flank
>>>    [37] follow            granges           isDisjoint        mcols
>>>    [41] mcols<-           narrow            nearest           order
>>>    [45] overlapsAny       precede           ranges            ranges<-
>>>    [49] rank              rbind             replaceROWS       resize
>>>    [53] restrict          rowData           rowData<-         seqinfo
>>>    [57] seqinfo<-         seqnames          shift             show
>>>    [61] sort              split             start             start<-
>>>    [65] strand            strand<-          subset
>>> subsetByOverlaps
>>>    [69] updateObject      values            values<-          width
>>>    [73] width<-
>>>
>>>    see ?"methods" for accessing help and source code
>>>
>>> and
>>>
>>>  head(attr(methods(class="SummarizedExperiment"), "info"))
>>>>
>>>                                                               generic
>>> visible
>>> [,SummarizedExperiment,ANY-method                                  [
>>> TRUE
>>> [[,SummarizedExperiment,ANY,missing-method                        [[
>>> TRUE
>>> [[<-,SummarizedExperiment,ANY,missing-method                    [[<-
>>> TRUE
>>> [<-,SummarizedExperiment,ANY,ANY,SummarizedExperiment-method     [<-
>>> TRUE
>>> $,SummarizedExperiment-method                                      $
>>> TRUE
>>> $<-,SummarizedExperiment-method                                  $<-
>>> TRUE
>>>                                                               isS4
>>>     from
>>> [,SummarizedExperiment,ANY-method                            TRUE
>>> GenomicRanges
>>> [[,SummarizedExperiment,ANY,missing-method                   TRUE
>>> GenomicRanges
>>> [[<-,SummarizedExperiment,ANY,missing-method                 TRUE
>>> GenomicRanges
>>> [<-,SummarizedExperiment,ANY,ANY,SummarizedExperiment-method TRUE
>>> GenomicRanges
>>> $,SummarizedExperiment-method                                TRUE
>>> GenomicRanges
>>> $<-,SummarizedExperiment-method                              TRUE
>>> GenomicRanges
>>>
>>> Martin
>>>
>>>
>>>> Pete
>>>>
>>>> ____________________
>>>> Peter M. Haverty, Ph.D.
>>>> Genentech, Inc.
>>>> phaverty at gene.com
>>>>
>>>> On Wed, Mar 4, 2015 at 9:38 AM, Michael Lawrence <
>>>> lawrence.michael at gene.com>
>>>> wrote:
>>>>
>>>>  I think we need to make sure that there are enough benefits of
>>>>> something
>>>>> like GRangesFrame before we introduce yet another complicated and
>>>>> overlapping data structure into the framework. Prior to summarization,
>>>>> the
>>>>> ranges seem primary, after summarization, it may often make sense for
>>>>> them
>>>>> to be secondary. But I'm just not sure what we gain from a new data
>>>>> structure.
>>>>>
>>>>> On Wed, Mar 4, 2015 at 12:28 AM, Herv� Pag�s <hpages at fredhutch.org>
>>>>> wrote:
>>>>>
>>>>>  GRangesFrame is an interesting idea and I gave it some thoughts.
>>>>>>
>>>>>> There is this nice symmetry between GRanges and GRangesFrame:
>>>>>>
>>>>>> - GRanges = a naked GRanges + a DataFrame accessible via mcols()
>>>>>>
>>>>>> - GRangesFrame = a DataFrame + a naked GRanges accessible via
>>>>>>                    some accessor (e.g. rowRanges())
>>>>>>
>>>>>> So GRanges and GRangesFrame are equivalent in terms of what they
>>>>>> can hold, but different in terms of API: the former has the ranges
>>>>>> API as primary API and the DataFrame API on its mcols() component,
>>>>>> and the latter has the DataFrame API as primary API and the ranges
>>>>>> API on its rowRanges() component. Nice switch!
>>>>>>
>>>>>> What does this API switch bring us? A GRangesFrame object is now
>>>>>> an object that fully behaves like a DataFrame and people can also
>>>>>> perform range-based operations on its rowRanges() component.
>>>>>> Here is what I'm afraid is going to happen: people will also want
>>>>>> to be able to perform range-based operations *directly* on
>>>>>> these objects, i.e. without having to call rowRanges() first.
>>>>>> So for example when they do subsetByOverlaps(), subsetting
>>>>>> happens vertically. Also the Hits object returned by findOverlaps()
>>>>>> would contain row indices. Problem with this is that these objects
>>>>>> now start to suffer from the "dual personality syndrome". For
>>>>>> example, it's not clear anymore what their length should be.
>>>>>> Strictly speaking it should be their number of columns (that's
>>>>>> what the length of a DataFrame is), but the ranges API that
>>>>>> we're trying to put on them also makes them feel like vectors
>>>>>> along the vertical dimension so it also feels that their length
>>>>>> should be their number of rows. Same thing with 1D subsetting.
>>>>>> Why does it subset the columns and not the rows? Most people
>>>>>> are now confused.
>>>>>>
>>>>>> It's interesting to note that the same thing happens with GRanges
>>>>>> objects, but in the opposite direction: people wish they could
>>>>>> do DataFrame operations directly on them without calling mcols()
>>>>>> first. But in order to preserve the good health of GRanges objects,
>>>>>> we've not done that (except for $, a shortcut for mcols(x)$,
>>>>>> the pressure was just too strong).
>>>>>>
>>>>>> H.
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 03/03/2015 04:35 PM, Michael Lawrence wrote:
>>>>>>
>>>>>>  Should be possible for the annotations to be of any type, as long as
>>>>>>> they
>>>>>>> satisfy a simple contract of NROW() and 2D "[". Then, you could have
>>>>>>> a
>>>>>>> DataFrame, GRanges, or whatever in there. But it would be nice to
>>>>>>> have a
>>>>>>> special class for the container with range information. The contract
>>>>>>> for
>>>>>>> the range annotation would be to have a granges() method.
>>>>>>>
>>>>>>> I agree it would be nice if there was a way with the methods package
>>>>>>> to
>>>>>>> easily assert such contracts. For example, one could define an
>>>>>>> interface
>>>>>>> with a set of generics (and optionally the relevant position in the
>>>>>>> generic
>>>>>>> signature). Then, once all of the methods have been assigned for a
>>>>>>> particular class, it is made to inherit from that contract class.
>>>>>>> There
>>>>>>> are
>>>>>>> lots of gotchas though. Not sure how useful it would be in practice.
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Mar 3, 2015 at 4:07 PM, Peter Haverty <
>>>>>>> haverty.peter at gene.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>    There are some nice similarities in these new imaginary types.  A
>>>>>>>
>>>>>>>>
>>>>>>>> "GRangesFrame" is a list of dimensionally identical things
>>>>>>>> (columns) and
>>>>>>>> some row meta-data (the GRanges).  The SE-like object is similarly a
>>>>>>>> list
>>>>>>>> of dimensionally like things (matrices, RleDataFrames, BigMatrix
>>>>>>>> objects,
>>>>>>>> HDF5-backed things) with some row meta-data (a DataFrame or
>>>>>>>> GRangesFrame).
>>>>>>>> Elegant?  Maybe they would actually be relatives in the class tree.
>>>>>>>>
>>>>>>>> I wonder if this kind of thing would be easier if we had Java-style
>>>>>>>> Interfaces or duck-typing.  The "x" slot of "y" holds something that
>>>>>>>> implements this set of methods ...
>>>>>>>>
>>>>>>>> Oh, and kinda apropos, the genoset class will probably go away or
>>>>>>>> become
>>>>>>>> an extension to this new SE-like thing.  The extra stuff that comes
>>>>>>>> along
>>>>>>>> with genoset will still be available.
>>>>>>>>
>>>>>>>> Pete
>>>>>>>>
>>>>>>>> ____________________
>>>>>>>> Peter M. Haverty, Ph.D.
>>>>>>>> Genentech, Inc.
>>>>>>>> phaverty at gene.com
>>>>>>>>
>>>>>>>> On Tue, Mar 3, 2015 at 3:42 PM, Tim Triche, Jr. <
>>>>>>>> tim.triche at gmail.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>    This.
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> It would be damned near perfect as a return value for assays coming
>>>>>>>>> out of
>>>>>>>>> an object that held several such assays at several time points in a
>>>>>>>>> population, where there are both assay-wise and covariate-wise
>>>>>>>>> "holes"
>>>>>>>>> that
>>>>>>>>> could nonetheless be usefully imputed across assays.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Statistics is the grammar of science.
>>>>>>>>> Karl Pearson <http://en.wikipedia.org/wiki/The_Grammar_of_Science>
>>>>>>>>>
>>>>>>>>> On Tue, Mar 3, 2015 at 3:25 PM, Peter Haverty <
>>>>>>>>> haverty.peter at gene.com>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>     I still think GRanges should be a subclass of DataFrame,
>>>>>>>>>>>
>>>>>>>>>>>  which would make this easy, but I don't seem to be winning that
>>>>>>>>>>>>
>>>>>>>>>>>>  argument.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>>  Just impossible. As Michael mentioned back in November, they
>>>>>>>>>>> have
>>>>>>>>>>> conflicting APIs.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Maybe a new "GRangesFrame" that is a DataFrame and holds a GRanges
>>>>>>>>>> (without mcols) as an index?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>            [[alternative HTML version deleted]]
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> Bioc-devel at r-project.org mailing list
>>>>>>>>>> https://stat.ethz.ch/mailman/listinfo/bioc-devel
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             [[alternative HTML version deleted]]
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> Bioc-devel at r-project.org mailing list
>>>>>>>>> https://stat.ethz.ch/mailman/listinfo/bioc-devel
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>            [[alternative HTML version deleted]]
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Bioc-devel at r-project.org mailing list
>>>>>>> https://stat.ethz.ch/mailman/listinfo/bioc-devel
>>>>>>>
>>>>>>>
>>>>>>>  --
>>>>>> Herv� Pag�s
>>>>>>
>>>>>> Program in Computational Biology
>>>>>> Division of Public Health Sciences
>>>>>> Fred Hutchinson Cancer Research Center
>>>>>> 1100 Fairview Ave. N, M1-B514
>>>>>> P.O. Box 19024
>>>>>> Seattle, WA 98109-1024
>>>>>>
>>>>>> E-mail: hpages at fredhutch.org
>>>>>> Phone:  (206) 667-5791
>>>>>> Fax:    (206) 667-1319
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>          [[alternative HTML version deleted]]
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Bioc-devel at r-project.org mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/bioc-devel
>>>>
>>>>
>>>
>>> --
>>> Computational Biology / Fred Hutchinson Cancer Research Center
>>> 1100 Fairview Ave. N.
>>> PO Box 19024 Seattle, WA 98109
>>>
>>> Location: Arnold Building M1 B861
>>> Phone: (206) 667-2793
>>>
>>>
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>>>
>>
>> _______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/bioc-devel
>>
>>
>
> --
> Computational Biology / Fred Hutchinson Cancer Research Center
> 1100 Fairview Ave. N, Seattle, WA 98109
>
> Email: vobencha at fredhutch.org
> Phone: (206) 667-3158
>
>
> _______________________________________________
> Bioc-devel at r-project.org mailing list
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