

On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
That seems like it would sometimes be a useful function, and maybe
someone will point out a package that already contains it. But if not,
why would it belong in base R?
Duncan Murdoch
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On 20191011 04:45, Duncan Murdoch wrote:
> On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
>> Hi All,
>>
>> I was looking for a function to find a small matrix inside a larger
>> matrix
>> in R similar to the one described in the following link:
>>
>> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix
>>
>>
>> I couldn't find anything.
>>
>> The above function can be seen as a "generalisation" of the "which"
>> function as well as the function described in the following post:
>>
>> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/
>>
>>
>> Would be possible to add such a function to base R?
>>
>> I am happy to work with someone from the R core team (if you wish) and
>> suggest an implementation in C.
>
> That seems like it would sometimes be a useful function, and maybe
> someone will point out a package that already contains it. But if
> not, why would it belong in base R?
The natural thing could be to add it to another existing package.
A list of different search tools appear in the Wikiversity
article on "Searching R packages".[1] I especially like the "sos"
package, which includes a vignette, [2] but I also use RDocumentation
and occasionally Rseek. Google Advanced Search[3] is also very good;
I've used that for other things, but not searching for R packages.
I've had modest luck suggesting additions to other packages if I
write the function and documentation with good examples that tend to
ensure quality. Some maintainers reject my suggestions; other have
accepted them.
Spencer Graves
[1]
https://en.wikiversity.org/wiki/Searching_R_Packages[2] Caveat: I wrote both that Wikiversity article and the "sos"
package, so I'm biased.
[3]
https://www.google.com/advanced_search>
> Duncan Murdoch
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rdevel______________________________________________
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On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]> wrote:
> On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
> > Hi All,
> >
> > I was looking for a function to find a small matrix inside a larger
> matrix
> > in R similar to the one described in the following link:
> >
> >
> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> >
> > I couldn't find anything.
> >
> > The above function can be seen as a "generalisation" of the "which"
> > function as well as the function described in the following post:
> >
> >
> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> >
> > Would be possible to add such a function to base R?
> >
> > I am happy to work with someone from the R core team (if you wish) and
> > suggest an implementation in C.
>
> That seems like it would sometimes be a useful function, and maybe
> someone will point out a package that already contains it. But if not,
> why would it belong in base R?
>
If someone already implemented it, that would great indeed. I think it is a
very general and basic function, hence base R could be a good place for it?
But this is probably not a good reason; maybe someone from the R core team
can shed some light on how they decide whether or not to include a function
in base R?
> Duncan Murdoch
>
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Hi Morgan,
I think there is a discussion on how developers include a function in base
R in another thread:
https://stat.ethz.ch/pipermail/rdevel/2019October/078551.htmlBest,
Jiefei
On Fri, Oct 11, 2019 at 8:19 AM Morgan Morgan < [hidden email]>
wrote:
> On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]>
> wrote:
>
> > On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
> > > Hi All,
> > >
> > > I was looking for a function to find a small matrix inside a larger
> > matrix
> > > in R similar to the one described in the following link:
> > >
> > >
> >
> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> > >
> > > I couldn't find anything.
> > >
> > > The above function can be seen as a "generalisation" of the "which"
> > > function as well as the function described in the following post:
> > >
> > >
> >
> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> > >
> > > Would be possible to add such a function to base R?
> > >
> > > I am happy to work with someone from the R core team (if you wish) and
> > > suggest an implementation in C.
> >
> > That seems like it would sometimes be a useful function, and maybe
> > someone will point out a package that already contains it. But if not,
> > why would it belong in base R?
> >
>
> If someone already implemented it, that would great indeed. I think it is a
> very general and basic function, hence base R could be a good place for it?
>
> But this is probably not a good reason; maybe someone from the R core team
> can shed some light on how they decide whether or not to include a function
> in base R?
>
>
> > Duncan Murdoch
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rdevel>
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Thanks for this interesting suggestion, Morgan. While there is no strict
criteria for base R inclusion, one criterion relevant in this case is that
the usefulness of a feature be proven in the package space first.
Michael
On Fri, Oct 11, 2019 at 5:19 AM Morgan Morgan < [hidden email]>
wrote:
> On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]>
> wrote:
>
> > On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
> > > Hi All,
> > >
> > > I was looking for a function to find a small matrix inside a larger
> > matrix
> > > in R similar to the one described in the following link:
> > >
> > >
> >
> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> > >
> > > I couldn't find anything.
> > >
> > > The above function can be seen as a "generalisation" of the "which"
> > > function as well as the function described in the following post:
> > >
> > >
> >
> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> > >
> > > Would be possible to add such a function to base R?
> > >
> > > I am happy to work with someone from the R core team (if you wish) and
> > > suggest an implementation in C.
> >
> > That seems like it would sometimes be a useful function, and maybe
> > someone will point out a package that already contains it. But if not,
> > why would it belong in base R?
> >
>
> If someone already implemented it, that would great indeed. I think it is a
> very general and basic function, hence base R could be a good place for it?
>
> But this is probably not a good reason; maybe someone from the R core team
> can shed some light on how they decide whether or not to include a function
> in base R?
>
>
> > Duncan Murdoch
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rdevel>

Michael Lawrence
Scientist, Bioinformatics and Computational Biology
Genentech, A Member of the Roche Group
Office +1 (650) 2257760
[hidden email]
Join Genentech on LinkedIn  Twitter  Facebook  Instagram  YouTube
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How do you prove usefulness of a feature?
Do you have an example of a feature that has been added after proving to be
useful in the package space first?
Thank you,
Morgan
On Fri, 11 Oct 2019 13:53 Michael Lawrence, < [hidden email]>
wrote:
> Thanks for this interesting suggestion, Morgan. While there is no strict
> criteria for base R inclusion, one criterion relevant in this case is that
> the usefulness of a feature be proven in the package space first.
>
> Michael
>
>
> On Fri, Oct 11, 2019 at 5:19 AM Morgan Morgan < [hidden email]>
> wrote:
>
>> On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]>
>> wrote:
>>
>> > On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
>> > > Hi All,
>> > >
>> > > I was looking for a function to find a small matrix inside a larger
>> > matrix
>> > > in R similar to the one described in the following link:
>> > >
>> > >
>> >
>> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix>> > >
>> > > I couldn't find anything.
>> > >
>> > > The above function can be seen as a "generalisation" of the "which"
>> > > function as well as the function described in the following post:
>> > >
>> > >
>> >
>> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/>> > >
>> > > Would be possible to add such a function to base R?
>> > >
>> > > I am happy to work with someone from the R core team (if you wish) and
>> > > suggest an implementation in C.
>> >
>> > That seems like it would sometimes be a useful function, and maybe
>> > someone will point out a package that already contains it. But if not,
>> > why would it belong in base R?
>> >
>>
>> If someone already implemented it, that would great indeed. I think it is
>> a
>> very general and basic function, hence base R could be a good place for
>> it?
>>
>> But this is probably not a good reason; maybe someone from the R core team
>> can shed some light on how they decide whether or not to include a
>> function
>> in base R?
>>
>>
>> > Duncan Murdoch
>> >
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> [hidden email] mailing list
>> https://stat.ethz.ch/mailman/listinfo/rdevel>>
>
>
> 
> Michael Lawrence
> Scientist, Bioinformatics and Computational Biology
> Genentech, A Member of the Roche Group
> Office +1 (650) 2257760
> [hidden email]
>
> Join Genentech on LinkedIn  Twitter  Facebook  Instagram  YouTube
>
[[alternative HTML version deleted]]
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It’s rather difficult. For example, the base R Kendall tau is written with
the naive O(n^2). The much faster O(n log n) implementation was programmed
and is in the pcaPP package. When I say much faster, I mean that my
implementation in Excel VBA was faster than R for 10,000 or so pairs.
RCore decided not to implement that code, and instead made a note about
the faster implementation living in pcaPP in the help for “cor”. See [1]
for the 2012 discussion. My point is it’s really really difficult to get
something in Base R. Develop it well, put it in a package, and you have
basically the same result.
Avi
[1] https://stat.ethz.ch/pipermail/rdevel/2012June/064351.htmlOn Fri, Oct 11, 2019 at 9:55 AM Morgan Morgan < [hidden email]>
wrote:
> How do you prove usefulness of a feature?
> Do you have an example of a feature that has been added after proving to be
> useful in the package space first?
>
> Thank you,
> Morgan
>
> On Fri, 11 Oct 2019 13:53 Michael Lawrence, < [hidden email]>
> wrote:
>
> > Thanks for this interesting suggestion, Morgan. While there is no strict
> > criteria for base R inclusion, one criterion relevant in this case is
> that
> > the usefulness of a feature be proven in the package space first.
> >
> > Michael
> >
> >
> > On Fri, Oct 11, 2019 at 5:19 AM Morgan Morgan < [hidden email]
> >
> > wrote:
> >
> >> On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]>
> >> wrote:
> >>
> >> > On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
> >> > > Hi All,
> >> > >
> >> > > I was looking for a function to find a small matrix inside a larger
> >> > matrix
> >> > > in R similar to the one described in the following link:
> >> > >
> >> > >
> >> >
> >>
> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> >> > >
> >> > > I couldn't find anything.
> >> > >
> >> > > The above function can be seen as a "generalisation" of the "which"
> >> > > function as well as the function described in the following post:
> >> > >
> >> > >
> >> >
> >>
> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> >> > >
> >> > > Would be possible to add such a function to base R?
> >> > >
> >> > > I am happy to work with someone from the R core team (if you wish)
> and
> >> > > suggest an implementation in C.
> >> >
> >> > That seems like it would sometimes be a useful function, and maybe
> >> > someone will point out a package that already contains it. But if
> not,
> >> > why would it belong in base R?
> >> >
> >>
> >> If someone already implemented it, that would great indeed. I think it
> is
> >> a
> >> very general and basic function, hence base R could be a good place for
> >> it?
> >>
> >> But this is probably not a good reason; maybe someone from the R core
> team
> >> can shed some light on how they decide whether or not to include a
> >> function
> >> in base R?
> >>
> >>
> >> > Duncan Murdoch
> >> >
> >>
> >> [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> [hidden email] mailing list
> >> https://stat.ethz.ch/mailman/listinfo/rdevel> >>
> >
> >
> > 
> > Michael Lawrence
> > Scientist, Bioinformatics and Computational Biology
> > Genentech, A Member of the Roche Group
> > Office +1 (650) 2257760
> > [hidden email]
> >
> > Join Genentech on LinkedIn  Twitter  Facebook  Instagram  YouTube
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rdevel>

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I think you are confusing package and function here. Plus some of the R
Core packages, that you mention, contain functions that should probably be
replaced by functions with better implementation from packages on CRAN.
Best regards
Morgan
On Fri, 11 Oct 2019 15:22 Joris Meys, < [hidden email]> wrote:
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Using the example in the link here are two oneliners:
A < c(2,3,4,1,2,3,4,1,1,2)
x < c(1,2)
# 1  zoo
library(zoo)
which( rollapply(A, length(x), identical, x, fill = FALSE, align = "left") )
## [1] 4 9
# 2  Base R using conversion to character
gregexpr(paste(x, collapse = ""), paste(A, collapse = ""))[[1]]
## [1] 4 9
...snip ...
On Fri, Oct 11, 2019 at 3:45 AM Morgan Morgan < [hidden email]> wrote:

Statistics & Software Consulting
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Perhaps. But aren’t you looking to implementation a function which finds a
submatrix? If I’m confused, please accept my apologies.
Avi
On Fri, Oct 11, 2019 at 10:43 AM Morgan Morgan < [hidden email]>
wrote:
> I think you are confusing package and function here. Plus some of the R
> Core packages, that you mention, contain functions that should probably be
> replaced by functions with better implementation from packages on CRAN.
>
> Best regards
> Morgan
>
> On Fri, 11 Oct 2019 15:22 Joris Meys, < [hidden email]> wrote:
>
> >
> >
> > On Fri, Oct 11, 2019 at 3:55 PM Morgan Morgan < [hidden email]
> >
> > wrote:
> >
> >> How do you prove usefulness of a feature?
> >> Do you have an example of a feature that has been added after proving to
> >> be
> >> useful in the package space first?
> >>
> >> Thank you,
> >> Morgan
> >>
> >
> > The parallel package (a base package like utils, stats, ...) was added as
> > a dropin replacement of the packages snow and multicore for parallel
> > computing. That's one example, but sure there's more.
> >
> > Kind regards
> > Joris
> >
> > 
> > Joris Meys
> > Statistical consultant
> >
> > Department of Data Analysis and Mathematical Modelling
> > Ghent University
> > Coupure Links 653, B9000 Gent (Belgium)
> >
> > <
> https://maps.google.com/?q=Coupure+links+653,%C2%A0B9000+Gent,%C2%A0Belgium&entry=gmail&source=g> >
> >
> > 
> > Biowiskundedagen 20182019
> > http://www.biowiskundedagen.ugent.be/> >
> > 
> > Disclaimer : http://helpdesk.ugent.be/emaildisclaimer.php> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rdevel>

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Also note that the functionality discussed could be regarded as a generalization
of matrix multiplication where * and + are general functions and in this case
we have * replaced by == and + replaced by &.
On Fri, Oct 11, 2019 at 10:46 AM Gabor Grothendieck
< [hidden email]> wrote:
>
> Using the example in the link here are two oneliners:
>
> A < c(2,3,4,1,2,3,4,1,1,2)
> x < c(1,2)
>
> # 1  zoo
> library(zoo)
> which( rollapply(A, length(x), identical, x, fill = FALSE, align = "left") )
> ## [1] 4 9
>
> # 2  Base R using conversion to character
> gregexpr(paste(x, collapse = ""), paste(A, collapse = ""))[[1]]
> ## [1] 4 9
> ...snip ...
>
> On Fri, Oct 11, 2019 at 3:45 AM Morgan Morgan < [hidden email]> wrote:
> >
> > Hi All,
> >
> > I was looking for a function to find a small matrix inside a larger matrix
> > in R similar to the one described in the following link:
> >
> > https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> >
> > I couldn't find anything.
> >
> > The above function can be seen as a "generalisation" of the "which"
> > function as well as the function described in the following post:
> >
> > https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> >
> > Would be possible to add such a function to base R?
> >
> > I am happy to work with someone from the R core team (if you wish) and
> > suggest an implementation in C.
> >
> > Thank you
> > Best regards,
> > Morgan
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > [hidden email] mailing list
> > https://stat.ethz.ch/mailman/listinfo/rdevel>
>
>
> 
> Statistics & Software Consulting
> GKX Group, GKX Associates Inc.
> tel: 1877GKXGROUP
> email: ggrothendieck at gmail.com

Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1877GKXGROUP
email: ggrothendieck at gmail.com
______________________________________________
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As a package is a collection of functions, and as "base" is not used to
refer to the base package but to all packages that form "base R" (so utils,
graphics, stats, methods, parallel, ...), the functions in the parallel
package are one example of functions incorporated in "base R" from a
package. Actually two, because the functions in parallel are based on both
snow and multicore.
This has no relation to changes in implementation (which often don't happen
due to backcompatibility issues in edge cases).
Kind regards
Joris
On Fri, Oct 11, 2019 at 4:42 PM Morgan Morgan < [hidden email]>
wrote:
> I think you are confusing package and function here. Plus some of the R
> Core packages, that you mention, contain functions that should probably be
> replaced by functions with better implementation from packages on CRAN.
>
> Best regards
> Morgan
>
> On Fri, 11 Oct 2019 15:22 Joris Meys, < [hidden email]> wrote:
>
>>
>>
>> On Fri, Oct 11, 2019 at 3:55 PM Morgan Morgan < [hidden email]>
>> wrote:
>>
>>> How do you prove usefulness of a feature?
>>> Do you have an example of a feature that has been added after proving to
>>> be
>>> useful in the package space first?
>>>
>>> Thank you,
>>> Morgan
>>>
>>
>> The parallel package (a base package like utils, stats, ...) was added as
>> a dropin replacement of the packages snow and multicore for parallel
>> computing. That's one example, but sure there's more.
>>
>> Kind regards
>> Joris
>>
>> 
>> Joris Meys
>> Statistical consultant
>>
>> Department of Data Analysis and Mathematical Modelling
>> Ghent University
>> Coupure Links 653, B9000 Gent (Belgium)
>>
>> < https://maps.google.com/?q=Coupure+links+653,%C2%A0B9000+Gent,%C2%A0Belgium&entry=gmail&source=g>
>>
>> 
>> Biowiskundedagen 20182019
>> http://www.biowiskundedagen.ugent.be/>>
>> 
>> Disclaimer : http://helpdesk.ugent.be/emaildisclaimer.php>>
>

Joris Meys
Statistical consultant
Department of Data Analysis and Mathematical Modelling
Ghent University
Coupure Links 653, B9000 Gent (Belgium)
< https://maps.google.com/?q=Coupure+links+653,%C2%A0B9000+Gent,%C2%A0Belgium&entry=gmail&source=g>

Biowiskundedagen 20182019
http://www.biowiskundedagen.ugent.be/
Disclaimer : http://helpdesk.ugent.be/emaildisclaimer.php [[alternative HTML version deleted]]
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Your answer makes much more sense to me.
I will probably end up adding the function to a package.
Some processes and decisions on how R is developed seems to be obscure to
me.
Thank you
Morgan
On Fri, 11 Oct 2019 15:30 Avraham Adler, < [hidden email]> wrote:
> It’s rather difficult. For example, the base R Kendall tau is written with
> the naive O(n^2). The much faster O(n log n) implementation was programmed
> and is in the pcaPP package. When I say much faster, I mean that my
> implementation in Excel VBA was faster than R for 10,000 or so pairs.
> RCore decided not to implement that code, and instead made a note about
> the faster implementation living in pcaPP in the help for “cor”. See [1]
> for the 2012 discussion. My point is it’s really really difficult to get
> something in Base R. Develop it well, put it in a package, and you have
> basically the same result.
>
> Avi
>
> [1] https://stat.ethz.ch/pipermail/rdevel/2012June/064351.html>
> On Fri, Oct 11, 2019 at 9:55 AM Morgan Morgan < [hidden email]>
> wrote:
>
>> How do you prove usefulness of a feature?
>> Do you have an example of a feature that has been added after proving to
>> be
>> useful in the package space first?
>>
>> Thank you,
>> Morgan
>>
>> On Fri, 11 Oct 2019 13:53 Michael Lawrence, < [hidden email]>
>> wrote:
>>
>> > Thanks for this interesting suggestion, Morgan. While there is no strict
>> > criteria for base R inclusion, one criterion relevant in this case is
>> that
>> > the usefulness of a feature be proven in the package space first.
>> >
>> > Michael
>> >
>> >
>> > On Fri, Oct 11, 2019 at 5:19 AM Morgan Morgan <
>> [hidden email]>
>> > wrote:
>> >
>> >> On Fri, 11 Oct 2019 10:45 Duncan Murdoch, < [hidden email]>
>> >> wrote:
>> >>
>> >> > On 11/10/2019 6:44 a.m., Morgan Morgan wrote:
>> >> > > Hi All,
>> >> > >
>> >> > > I was looking for a function to find a small matrix inside a larger
>> >> > matrix
>> >> > > in R similar to the one described in the following link:
>> >> > >
>> >> > >
>> >> >
>> >>
>> https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix>> >> > >
>> >> > > I couldn't find anything.
>> >> > >
>> >> > > The above function can be seen as a "generalisation" of the "which"
>> >> > > function as well as the function described in the following post:
>> >> > >
>> >> > >
>> >> >
>> >>
>> https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/>> >> > >
>> >> > > Would be possible to add such a function to base R?
>> >> > >
>> >> > > I am happy to work with someone from the R core team (if you wish)
>> and
>> >> > > suggest an implementation in C.
>> >> >
>> >> > That seems like it would sometimes be a useful function, and maybe
>> >> > someone will point out a package that already contains it. But if
>> not,
>> >> > why would it belong in base R?
>> >> >
>> >>
>> >> If someone already implemented it, that would great indeed. I think it
>> is
>> >> a
>> >> very general and basic function, hence base R could be a good place for
>> >> it?
>> >>
>> >> But this is probably not a good reason; maybe someone from the R core
>> team
>> >> can shed some light on how they decide whether or not to include a
>> >> function
>> >> in base R?
>> >>
>> >>
>> >> > Duncan Murdoch
>> >> >
>> >>
>> >> [[alternative HTML version deleted]]
>> >>
>> >> ______________________________________________
>> >> [hidden email] mailing list
>> >> https://stat.ethz.ch/mailman/listinfo/rdevel>> >>
>> >
>> >
>> > 
>> > Michael Lawrence
>> > Scientist, Bioinformatics and Computational Biology
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I pressed return too soon.
If we had such a multiply then
which(embed(A, x) %==.&% reverse(x))
On Fri, Oct 11, 2019 at 10:57 AM Gabor Grothendieck
< [hidden email]> wrote:
>
> Also note that the functionality discussed could be regarded as a generalization
> of matrix multiplication where * and + are general functions and in this case
> we have * replaced by == and + replaced by &.
>
> On Fri, Oct 11, 2019 at 10:46 AM Gabor Grothendieck
> < [hidden email]> wrote:
> >
> > Using the example in the link here are two oneliners:
> >
> > A < c(2,3,4,1,2,3,4,1,1,2)
> > x < c(1,2)
> >
> > # 1  zoo
> > library(zoo)
> > which( rollapply(A, length(x), identical, x, fill = FALSE, align = "left") )
> > ## [1] 4 9
> >
> > # 2  Base R using conversion to character
> > gregexpr(paste(x, collapse = ""), paste(A, collapse = ""))[[1]]
> > ## [1] 4 9
> > ...snip ...
> >
> > On Fri, Oct 11, 2019 at 3:45 AM Morgan Morgan < [hidden email]> wrote:
> > >
> > > Hi All,
> > >
> > > I was looking for a function to find a small matrix inside a larger matrix
> > > in R similar to the one described in the following link:
> > >
> > > https://www.mathworks.com/matlabcentral/answers/194708indexasmallmatrixinalargermatrix> > >
> > > I couldn't find anything.
> > >
> > > The above function can be seen as a "generalisation" of the "which"
> > > function as well as the function described in the following post:
> > >
> > > https://coolbutuseless.github.io/2018/04/03/findingalengthnneedleinahaystack/> > >
> > > Would be possible to add such a function to base R?
> > >
> > > I am happy to work with someone from the R core team (if you wish) and
> > > suggest an implementation in C.
> > >
> > > Thank you
> > > Best regards,
> > > Morgan
> > >
> > > [[alternative HTML version deleted]]
> > >
> > > ______________________________________________
> > > [hidden email] mailing list
> > > https://stat.ethz.ch/mailman/listinfo/rdevel> >
> >
> >
> > 
> > Statistics & Software Consulting
> > GKX Group, GKX Associates Inc.
> > tel: 1877GKXGROUP
> > email: ggrothendieck at gmail.com
>
>
>
> 
> Statistics & Software Consulting
> GKX Group, GKX Associates Inc.
> tel: 1877GKXGROUP
> email: ggrothendieck at gmail.com

Statistics & Software Consulting
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Has someone looked into the image processing area for this? That sounds
a little bit too highlevel for base R to me (and I would be surprised
if any mainstream programming language had this kind of functionality
builtin).
H.
On 10/11/19 03:44, Morgan Morgan wrote:

Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1B514
P.O. Box 19024
Seattle, WA 981091024
Email: [hidden email]
Phone: (206) 6675791
Fax: (206) 6671319
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The link you posted used the same inputs as in my example. If that is
not what you meant maybe
a different example is needed.
Regards.
On Fri, Oct 11, 2019 at 2:39 PM Pages, Herve < [hidden email]> wrote:

Statistics & Software Consulting
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tel: 1877GKXGROUP
email: ggrothendieck at gmail.com
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