[BioC] GenomicRanges: nearest() for GRanges not returning overlaps

Valerie Obenchain vobencha at fhcrc.org
Tue Aug 21 19:19:54 CEST 2012


Hi James,

nearest() for GenomicRanges now findes self-hits when both 'x' and 
'subject' are present but not when only 'x' is present. This change was 
made in GenomicRanges 1.9.53 in devel which should be available through 
biocLite() tomorrow morning ~9am PST.

Valerie


On 07/05/2012 09:14 AM, Valerie Obenchain wrote:
> Your statement is true except in the case where the query and subject 
> are the same (original discussion below). When query and subject are 
> the same (or contain >=1 of the same ranges) nearest() should choose 
> self-hits. precede() and follow() will never select self-hits because 
> they do not 'precede' or 'follow' them.
>
> These unit tests may help further explain the behavior we are 
> expecting for "+", "-" and "*".
>
>     r <- IRanges(c(1,5,10), c(2,7,12))
>     g <- GRanges("chr1", r, "+")
>     checkEquals(precede(r), precede(g))
>     checkEquals(follow(r), follow(g))
>     checkEquals(nearest(r), nearest(g))
>
>     g <- GRanges("chr1", r, "-")
>     checkEquals(follow(r), precede(g))
>     checkEquals(precede(r), follow(g))
>     checkEquals(nearest(r), nearest(g))
>
>     g <- GRanges("chr1", r, "*")
>     checkEquals(follow(g), precede(g))
>     checkEquals(nearest(r), follow(g))
>     checkEquals(follow(g), nearest(g))
>
>
> Valerie
>
>
> On 07/04/2012 02:12 AM, James Perkins wrote:
>> Thanks a lot Valerie!
>>
>> So precede with "*" is analogous to nearest? Since the nearest will
>> also be preceding it either + or - direction?
>>
>> Jim
>>
>> On 3 July 2012 21:04, Valerie Obenchain<vobencha at fhcrc.org>  wrote:
>>> Hi James,
>>>
>>> Thanks for the bug report. The nearest,GRanges method is currently not
>>> selecting any range that includes itself. It should behave like 
>>> IRanges and
>>> excluded self hits when one argument is supplied but not when the same
>>> argument is both query and subject. I'll post back here when it is 
>>> fixed.
>>>
>>> Here is an example that will help explain how '*' is treated as far as
>>> matching. For precede(), follow() and nearest() the '*' strand is 
>>> treated as
>>> '+' and '-' when looking for potential matches.
>>>
>>>> q<- GRanges("chr1", IRanges(c(1, 3, 9), c(2, 7, 10)))
>>>> q
>>> GRanges with 3 ranges and 0 elementMetadata cols:
>>>        seqnames    ranges strand
>>> <Rle> <IRanges> <Rle>
>>>    [1]     chr1   [1,  2]      *
>>>    [2]     chr1   [3,  7]      *
>>>    [3]     chr1   [9, 10]      *
>>>    ---
>>>    seqlengths:
>>>     chr1
>>>       NA
>>>
>>> ## The second range could be seen as preceding range 3 on '+'
>>> ## or preceding range 1 on '-'. Range 1 is closer so it is chosen.
>>> ## The third range precedes no range on '+' but precedes
>>> ## range 2 on '-' so range 2 is chosen.
>>>> precede(q)
>>> [1] 2 1 2
>>>> precede(ranges(q))
>>> [1]  2  3 NA
>>>
>>> ## When the strand is '+' GRanges and IRanges behave the same.
>>>> strand(q)<- "+"
>>>> precede(q)
>>> [1]  2  3 NA
>>>> precede(ranges(q))
>>> [1]  2  3 NA
>>>
>>> ## When the strand is '-' GRanges treats the ranges as '-' but
>>> ## IRanges is unstranded so they are treated as '+'.
>>>> strand(q)<- "-"
>>>> precede(q)
>>> [1] NA  1  2
>>>> precede(ranges(q))
>>> [1]  2  3 NA
>>>
>>> Valerie
>>>
>>>
>>> On 07/03/12 10:58, James Perkins wrote:
>>>> Thanks,
>>>>
>>>> But it appears in the example (using GenomicRanges_1.8.7), the second
>>>> range is being excluded? I.e. 3-7 matches 5-6 (and 1-3) and thus is
>>>>
>>>>> subject2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(3, 5, 12),
>>>> +>> >   c(3, 6, 12)))
>>>>> subject2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(3, 5, 12),
>>>>> c(3, 6, 12)))
>>>>> query2
>>>> GRanges with 3 ranges and 0 elementMetadata cols:
>>>>         seqnames    ranges strand
>>>> <Rle> <IRanges> <Rle>
>>>>     [1]     chr1   [1,  2]      *
>>>>     [2]     chr1   [3,  7]      *
>>>>     [3]     chr1   [9, 10]      *
>>>>     ---
>>>>     seqlengths:
>>>>      chr1
>>>>        NA
>>>>> subject2
>>>> GRanges with 3 ranges and 0 elementMetadata cols:
>>>>         seqnames    ranges strand
>>>> <Rle> <IRanges> <Rle>
>>>>     [1]     chr1  [ 3,  3]      *
>>>>     [2]     chr1  [ 5,  6]      *
>>>>     [3]     chr1  [12, 12]      *
>>>>     ---
>>>>     seqlengths:
>>>>      chr1
>>>>        NA
>>>>> nearest(query2, subject2)
>>>> [1] 1 3 3
>>>>> nearest(subject2, query2)
>>>> [1] 1 1 3
>>>>
>>>> Similarly
>>>>
>>>> nearest(query2, query2)
>>>> [1] 2 1 2
>>>>
>>>> should surely be "1 2 3"? Or have I missed something?
>>>>
>>>> IRanges is as I would expect:>   nearest(ranges(query2), 
>>>> ranges(subject2))
>>>> [1] 1 1 3
>>>>
>>>>
>>>> Jim
>>>>
>>>>
>>>> On 3 July 2012 19:40, Michael Lawrence<lawrence.michael at gene.com>   
>>>> wrote:
>>>>> The way IRanges works is that the self hits are excluded (by default)
>>>>> when
>>>>> only one argument is passed to nearest(). They should not be excluded
>>>>> when
>>>>> the same object is passed as both arguments.
>>>>>
>>>>> Michael
>>>>>
>>>>> On Tue, Jul 3, 2012 at 7:09 AM, James 
>>>>> Perkins<jperkins at biochem.ucl.ac.uk>
>>>>> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I read this:
>>>>>>
>>>>>> https://mailman.stat.ethz.ch/pipermail/bioconductor/2012-June/046287.html 
>>>>>>
>>>>>>
>>>>>> However, after reading it I'm a little confused as to what the 
>>>>>> default
>>>>>> behaviour should be when using nearest with '*', and also how to get
>>>>>> back to what I believe was the previous, "IRanges" style behaviour.
>>>>>>
>>>>>> Is nearest on GRanges supposed to act like nearest on IRanges, or is
>>>>>> it instead supposed to return the nearest neighbour OTHER than the
>>>>>> query one?
>>>>>>
>>>>>> I.e.
>>>>>>
>>>>>>
>>>>>>> query<- IRanges(c(1, 3, 9), c(2, 7, 10))
>>>>>>> subject<- IRanges(c(3, 5, 12), c(3, 6, 12))
>>>>>>> nearest(query, subject)
>>>>>> [1] 1 1 3
>>>>>>
>>>>>> Because, it seems to be behaving differently, i.e. returning the
>>>>>> neighbour only, i.e.
>>>>>>
>>>>>>
>>>>>>> query2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(1, 3, 9),
>>>>>>> c(2, 7, 10)))
>>>>>>> subject2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(3, 5, 
>>>>>>> 12),
>>>>>>> c(3, 6, 12)))
>>>>>>> nearest(query2, subject2)
>>>>>> [1] 1 3 2
>>>>>>> sessionInfo()
>>>>>> R version 2.15.1 (2012-06-22)
>>>>>> Platform: x86_64-unknown-linux-gnu (64-bit)
>>>>>>
>>>>>> locale:
>>>>>>    [1] LC_CTYPE=en_US             LC_NUMERIC=C
>>>>>>    [3] LC_TIME=en_GB.UTF-8        LC_COLLATE=en_GB.UTF-8
>>>>>>    [5] LC_MONETARY=en_GB.UTF-8    LC_MESSAGES=en_GB.UTF-8
>>>>>>    [7] LC_PAPER=C                 LC_NAME=C
>>>>>>    [9] LC_ADDRESS=C               LC_TELEPHONE=C
>>>>>> [11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C
>>>>>>
>>>>>> attached base packages:
>>>>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>>>>
>>>>>> other attached packages:
>>>>>> [1] GenomicRanges_1.8.7 IRanges_1.14.4      BiocGenerics_0.2.0
>>>>>>
>>>>>> loaded via a namespace (and not attached):
>>>>>> [1] stats4_2.15.1
>>>>>>
>>>>>>
>>>>>> However, what makes me confused is that the previous behaviour 
>>>>>> was like
>>>>>> IRanges:
>>>>>>
>>>>>>> query<- IRanges(c(1, 3, 9), c(2, 7, 10))
>>>>>>> subject<- IRanges(c(3, 5, 12), c(3, 6, 12))
>>>>>>> nearest(query, subject)
>>>>>> [1] 1 1 3
>>>>>>> query2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(1, 1, 12),
>>>>>>> c(2, 7, 12)))
>>>>>>> subject2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(3, 5, 
>>>>>>> 12),
>>>>>>> c(3, 6, 12)))
>>>>>>> nearest(query2, subject2)
>>>>>> [1] 1 1 3
>>>>>>> sessionInfo()
>>>>>> R version 2.15.0 (2012-03-30)
>>>>>> Platform: x86_64-unknown-linux-gnu (64-bit)
>>>>>>
>>>>>> locale:
>>>>>>    [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>>>>>>    [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>>>>>>    [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
>>>>>>    [7] LC_PAPER=C                 LC_NAME=C
>>>>>>    [9] LC_ADDRESS=C               LC_TELEPHONE=C
>>>>>> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>>>>>>
>>>>>> attached base packages:
>>>>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>>>>
>>>>>> other attached packages:
>>>>>> [1] GenomicRanges_1.8.6 IRanges_1.14.3      BiocGenerics_0.2.0
>>>>>>
>>>>>> loaded via a namespace (and not attached):
>>>>>> [1] stats4_2.15.0
>>>>>>
>>>>>>
>>>>>> And in fact, this has always been the behaviour right? i.e.: for R
>>>>>> 2.13.1
>>>>>>
>>>>>>> query<- IRanges(c(1, 3, 9), c(2, 7, 10))
>>>>>>> subject<- IRanges(c(3, 5, 12), c(3, 6, 12))
>>>>>>> nearest(query, subject)
>>>>>> [1] 1 1 3
>>>>>>> query2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(1, 1, 12),
>>>>>>> c(2, 7, 12)))
>>>>>>> subject2<- GRanges(seqnames=rep('chr1',3),ranges=IRanges(c(3, 5, 
>>>>>>> 12),
>>>>>>> c(3, 6, 12)))
>>>>>>> nearest(query2, subject2)
>>>>>> [1] 1 1 3
>>>>>>> sessionInfo()
>>>>>> R version 2.13.1 (2011-07-08)
>>>>>> Platform: x86_64-pc-linux-gnu (64-bit)
>>>>>>
>>>>>> locale:
>>>>>>    [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>>>>>>    [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>>>>>>    [5] LC_MONETARY=C              LC_MESSAGES=en_US.UTF-8
>>>>>>    [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
>>>>>>    [9] LC_ADDRESS=C               LC_TELEPHONE=C
>>>>>> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>>>>>>
>>>>>> attached base packages:
>>>>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>>>>
>>>>>> other attached packages:
>>>>>> [1] GenomicRanges_1.4.8 IRanges_1.10.6
>>>>>>
>>>>>>
>>>>>> Is ignore.strand=TRUE intended to get the IRanges-like behaviour?
>>>>>> Because I have problems with this too:
>>>>>>
>>>>>>    nearest(x = query2, subject = subject2, ignore.strand=TRUE)
>>>>>> Error in strand(x)<- strand(subject)<- "+" : object 'x' not found
>>>>>>
>>>>>> Thanks!
>>>>>>
>>>>>> Jim
>>>>>>
>>>>>> _______________________________________________
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>>>>>
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>>>
>
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