[R] struggling with apply

[Mathew Guilfoyle]

A bit quicker:

t(pmin(t(somematrix), UB))



> On 27 May 2020, at 20:56, Bert Gunter <bgunter.4567 using gmail.com> wrote:
> 
> Jeff: Check it!
> 
>> somematrix <- matrix(c(1,4,3,6,3,9,12,8,5,7,11,11),nrow=3,ncol=4)
>> UB=c(2.5, 5.5, 8.5, 10.5)
>> apply( somematrix, 2, function( x ) pmin( x, UB ) )
>     [,1] [,2] [,3] [,4]
> [1,]    1  2.5  2.5  2.5
> [2,]    4  3.0  5.5  5.5
> [3,]    3  8.5  5.0  8.5
> [4,]    1  6.0 10.5  7.0
> 
> Not what was wanted.
> Am I missing something?
> 
> Bert Gunter
> 
> "The trouble with having an open mind is that people keep coming along and
> sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
> 
> 
> On Wed, May 27, 2020 at 12:38 PM Jeff Newmiller <jdnewmil using dcn.davis.ca.us <mailto:jdnewmil using dcn.davis.ca.us>>
> wrote:
> 
>> Sigh. Transpose?
>> 
>> apply( somematrix, 2, function( x ) pmin( x, UB ) )
>> 
>> On May 27, 2020 11:22:06 AM PDT, Bert Gunter <bgunter.4567 using gmail.com>
>> wrote:
>>> Better, I think (no indexing):
>>> 
>>> t(apply(somematrix,1,function(x)pmin(x,UB)))
>>> 
>>> 
>>> Bert Gunter
>>> 
>>> "The trouble with having an open mind is that people keep coming along
>>> and
>>> sticking things into it."
>>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>> 
>>> 
>>> On Wed, May 27, 2020 at 10:56 AM Rui Barradas <ruipbarradas using sapo.pt>
>>> wrote:
>>> 
>>>> Hello,
>>>> 
>>>> Try pmin. And loop by column/UB index with sapply/seq_along.
>>>> 
>>>> 
>>>> sapply(seq_along(UB), function(i) pmin(UB[i], somematrix[,i]))
>>>> #     [,1] [,2] [,3] [,4]
>>>> #[1,]  1.0  5.5  8.5  7.0
>>>> #[2,]  2.5  3.0  8.0 10.5
>>>> #[3,]  2.5  5.5  5.0 10.5
>>>> 
>>>> 
>>>> Hope this helps,
>>>> 
>>>> Rui Barradas
>>>> 
>>>> 
>>>> Às 18:46 de 27/05/20, Michael Ashton escreveu:
>>>>> Hi -
>>>>> 
>>>>> I have a matrix of n rows and 4 columns.
>>>>> 
>>>>> I want to cap the value in each column by a different upper bound.
>>> So,
>>>> suppose my matrix is
>>>>> 
>>>>> somematrix <- matrix(c(1,4,3,6,3,9,12,8,5,7,11,11),nrow=3,ncol=4)
>>>>>> somematrix
>>>>>      [,1] [,2] [,3] [,4]
>>>>> [1,]    1    6   12    7
>>>>> [2,]    4    3    8   11
>>>>> [3,]    3    9    5   11
>>>>> 
>>>>> Now I want to have the maximum value in each column described by
>>>>> UB=c(2.5, 5.5, 8.5, 10.5)
>>>>> 
>>>>> So that the right answer will look like:
>>>>>      [,1]      [,2]    [,3]   [,4]
>>>>> [1,]    1      5.5     8.5    7
>>>>> [2,]    2.5    3        8     10.5
>>>>> [3,]    2.5   5.5      5    10.5
>>>>> 
>>>>> I've tried a few things, like:
>>>>> newmatrix <- apply(somematrix,c(1,2),function(x) min(UB,x))
>>>>> 
>>>>> but I can't figure out to apply the relevant element of the UB list
>>> to
>>>> the right element of the matrix. When I run the above, for example,
>>> it
>>>> takes min(UB,x) over all UB, so I get:
>>>>> 
>>>>> newmatrix
>>>>>      [,1] [,2] [,3] [,4]
>>>>> [1,]  1.0  2.5  2.5  2.5
>>>>> [2,]  2.5  2.5  2.5  2.5
>>>>> [3,]  2.5  2.5  2.5  2.5
>>>>> 
>>>>> I'm sure there's a simple and elegant solution but I don't know
>>> what it
>>>> is!
>>>>> 
>>>>> Thanks in advance,
>>>>> 
>>>>> Mike
>>>>> 
>>>>> Michael Ashton, CFA
>>>>> Managing Principal
>>>>> 
>>>>> Enduring Investments LLC
>>>>> W: 973.457.4602
>>>>> C: 551.655.8006
>>>>> Schedule a Call: https://calendly.com/m-ashton
>>>>> 
>>>>> 
>>>>>      [[alternative HTML version deleted]]
>>>>> 
>>>>> ______________________________________________
>>>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>>> PLEASE do read the posting guide
>>>> http://www.R-project.org/posting-guide.html
>>>>> and provide commented, minimal, self-contained, reproducible code.
>>>>> 
>>>> 
>>>> ______________________________________________
>>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>> 
>>> 
>>>      [[alternative HTML version deleted]]
>>> 
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>> 
>> --
>> Sent from my phone. Please excuse my brevity.
>> 
> 
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> 
> ______________________________________________
> R-help using r-project.org <mailto:R-help using r-project.org> mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help <https://stat.ethz.ch/mailman/listinfo/r-help>
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html <http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.


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