Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
avi, On 2023-06-21 12:46, avi.e.gr...@gmail.com wrote: I was rushing out Phil so let me amend what I wrote. As others noted, this is fairly beginner stuff. If you have more such questions, besides reading up, please consider sending questions to the Tutor mailing list where there is more patience. No worries - thanks! You wanted to change selected small values to 0.0. So you do not want the code I supplied as illustration as it removes small elements making a smaller vector. Assume this test: A <- c(NA, 0.3, 0.6, NA, 0.9) B <- c(NA, 0.2, 0.6, 0.9, 0.9) C <- A * B print(C) The result at this point is: [1] NA 0.06 0.36 NA 0.81 As expected, anything with an NA in either vector will generate an NA in the componentwise multiplication. Note the second item at 0.06 is under your threshold of 0.1. What you want is not this: Result <- C[C < 0.1] Result [1] NA 0.06 NA That threw away anything above the threshold. Yes, I realised that later . . What you want may be this: C[C < 0.1] <- 0.0 print(C) This returns [1] NA 0.00 0.36 NA 0.81 Everything that is NA or at or above 0.1 is kept and anything below 0.1 is zeroed and kept. Of course, if you do not want to keep the NA, that can trivially be removed: C[!is.na(C)] [1] 0.00 0.36 0.81 I actually got there myself after a bit of experimenting! - but you pointed me in the right direction! Thanks! Phil. -Original Message- From: Philip Rhoades Sent: Tuesday, June 20, 2023 1:04 PM To: avi.e.gr...@gmail.com Cc: r-help@r-project.org Subject: Re: [R] Multiplying two vectors of the same size to give a third vector of the same size avi, On 2023-06-21 01:55, avi.e.gr...@gmail.com wrote: Phil, What have you tried. This seems straightforward enough. Could you clarify what you mean by NULL? I guess in R in would just be an empty cell? - ie NOT a zero. In R, it is common to use NA or a more specific version of it. Ah yes, that would be it I think. So assuming you have two vectors containing floats with some NA, then: C <- A*B Will give you the products one at a time if the lengths are the same. NA times anything is NA. Right - yes that works! - thanks! Your second condition is also simple as you want anything below a threshold to be set to a fixes value. Since you already have C, above, your condition of: threshold <- 0.1 C < threshold The last line returns a Boolean vector you can use to index C to get just the ones you select as TRUE and thus can change: Result <- C[C < threshold] Ah, I see . . And you can of course do all the above as a one-liner. Yes. Is that what you wanted? Exactly except I meant: Result <- C[C > threshold] Thanks! Phil. -Original Message- From: R-help On Behalf Of Philip Rhoades via R-help Sent: Tuesday, June 20, 2023 11:38 AM To: r-help@r-project.org Subject: [R] Multiplying two vectors of the same size to give a third vector of the same size People, I am assuming that what I want to do is easier in R than say Ruby. I want to do what the Subject says ie multiply the cells in the same position of two vectors (A and B) to give a result in the same position in a third vector (C) BUT: - The values in the cells of A and B are floats between 0.0 and 1.0 or NULL - If there is a NULL in the multiplication, then the result in the cell for C is also a NULL - If there is a value less than (say) 0.01 in the multiplication, then the result in the cell for C is 0.0 Any suggestions appreciated! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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@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. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
I was rushing out Phil so let me amend what I wrote. As others noted, this is fairly beginner stuff. If you have more such questions, besides reading up, please consider sending questions to the Tutor mailing list where there is more patience. You wanted to change selected small values to 0.0. So you do not want the code I supplied as illustration as it removes small elements making a smaller vector. Assume this test: A <- c(NA, 0.3, 0.6, NA, 0.9) B <- c(NA, 0.2, 0.6, 0.9, 0.9) C <- A * B print(C) The result at this point is: [1] NA 0.06 0.36 NA 0.81 As expected, anything with an NA in either vector will generate an NA in the componentwise multiplication. Note the second item at 0.06 is under your threshold of 0.1. What you want is not this: Result <- C[C < 0.1] > Result [1] NA 0.06 NA That threw away anything above the threshold. What you want may be this: C[C < 0.1] <- 0.0 print(C) This returns [1] NA 0.00 0.36 NA 0.81 Everything that is NA or at or above 0.1 is kept and anything below 0.1 is zeroed and kept. Of course, if you do not want to keep the NA, that can trivially be removed: C[!is.na(C)] [1] 0.00 0.36 0.81 -Original Message- From: Philip Rhoades Sent: Tuesday, June 20, 2023 1:04 PM To: avi.e.gr...@gmail.com Cc: r-help@r-project.org Subject: Re: [R] Multiplying two vectors of the same size to give a third vector of the same size avi, On 2023-06-21 01:55, avi.e.gr...@gmail.com wrote: > Phil, > > What have you tried. This seems straightforward enough. > > Could you clarify what you mean by NULL? I guess in R in would just be an empty cell? - ie NOT a zero. > In R, it is common to use NA or a more specific version of it. Ah yes, that would be it I think. > So assuming you have two vectors containing floats with some NA, then: > > C <- A*B > > Will give you the products one at a time if the lengths are the same. > NA > times anything is NA. Right - yes that works! - thanks! > Your second condition is also simple as you want anything below a > threshold > to be set to a fixes value. > > Since you already have C, above, your condition of: > > threshold <- 0.1 > C < threshold > > The last line returns a Boolean vector you can use to index C to get > just > the ones you select as TRUE and thus can change: > > Result <- C[C < threshold] Ah, I see . . > And you can of course do all the above as a one-liner. Yes. > Is that what you wanted? Exactly except I meant: Result <- C[C > threshold] Thanks! Phil. > -Original Message- > From: R-help On Behalf Of Philip Rhoades > via > R-help > Sent: Tuesday, June 20, 2023 11:38 AM > To: r-help@r-project.org > Subject: [R] Multiplying two vectors of the same size to give a third > vector > of the same size > > People, > > I am assuming that what I want to do is easier in R than say Ruby. > > I want to do what the Subject says ie multiply the cells in the same > position of two vectors (A and B) to give a result in the same position > in a third vector (C) BUT: > > - The values in the cells of A and B are floats between 0.0 and 1.0 or > NULL > > - If there is a NULL in the multiplication, then the result in the cell > for C is also a NULL > > - If there is a value less than (say) 0.01 in the multiplication, then > the result in the cell for C is 0.0 > > Any suggestions appreciated! > > Phil. > > -- > Philip Rhoades > > PO Box 896 > Cowra NSW 2794 > Australia > E-mail: p...@pricom.com.au > > __ > R-help@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@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. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] OK, next Q - a sort of factorial on a vector
Eric, On 2023-06-21 04:02, Eric Berger wrote: Hi Philip, In the decades since you learned R there have been some additions to the language. In particular, R now supports lambda functions. Applying this feature to Ivan's beautiful solution cuts down 7 characters (continuing his golfing analogy) unlist(lapply(seq_along(x), \(i) x[i] * x[-(1:i)])) Amazing! - it reminds me of the old days when there were competitions to write the smallest C programs . . Enjoy your return to R! Thanks! I think I was right to look at R first - it is exactly what I need I think - and the model I am thinking of shouldn't need any grunt that would require rewriting any functions in C or Rust or something . . P. On Tue, Jun 20, 2023 at 8:46 PM Philip Rhoades via R-help wrote: Ivan, On 2023-06-21 03:32, Ivan Krylov wrote: В Wed, 21 Jun 2023 03:13:52 +1000 Philip Rhoades via R-help пишет: This: !(1,2,3,4,5) would give this: (2,3,4,5, 6,8,10, 12,15, 20) Do you mean taking a product of every element of the vector with all following vector elements? A relatively straightforward way would be (given your vector stored in `x`): unlist(lapply(seq_along(x), function(i) x[i] * x[-(1:i)])) Perfect! (I'm sure it could be golfed further.) I will look at Sarah's suggestion too. and this: !(1,2,NA,4,5) would give this: (2,4,5, 8,10, 20) The previous solution seems to give your vector interspersed a bunch of NAs, so one way to continue would be to filter it using v[!is.na [1](v)]. Exactly! Thanks people - it would have taken forever to work that out myself (it has been decades since I looked at R). Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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. Links: -- [1] http://is.na -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] OK, next Q - a sort of factorial on a vector
Hi Philip, In the decades since you learned R there have been some additions to the language. In particular, R now supports lambda functions. Applying this feature to Ivan's beautiful solution cuts down 7 characters (continuing his golfing analogy) unlist(lapply(seq_along(x), \(i) x[i] * x[-(1:i)])) Enjoy your return to R! On Tue, Jun 20, 2023 at 8:46 PM Philip Rhoades via R-help < r-help@r-project.org> wrote: > Ivan, > > > On 2023-06-21 03:32, Ivan Krylov wrote: > > В Wed, 21 Jun 2023 03:13:52 +1000 > > Philip Rhoades via R-help пишет: > > > >> This: > >> > >>!(1,2,3,4,5) > >> > >> would give this: > >> > >>(2,3,4,5, 6,8,10, 12,15, 20) > > > > Do you mean taking a product of every element of the vector with all > > following vector elements? A relatively straightforward way would be > > (given your vector stored in `x`): > > > > unlist(lapply(seq_along(x), function(i) x[i] * x[-(1:i)])) > > > Perfect! > > > > (I'm sure it could be golfed further.) > > > I will look at Sarah's suggestion too. > > > >> and this: > >> > >>!(1,2,NA,4,5) > >> > >> would give this: > >> > >>(2,4,5, 8,10, 20) > > > > The previous solution seems to give your vector interspersed a bunch of > > NAs, so one way to continue would be to filter it using v[!is.na(v)]. > > > Exactly! > > Thanks people - it would have taken forever to work that out myself (it > has been decades since I looked at R). > > Phil. > -- > Philip Rhoades > > PO Box 896 > Cowra NSW 2794 > Australia > E-mail: p...@pricom.com.au > > __ > R-help@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@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.
Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
Bert, On 2023-06-21 03:31, Bert Gunter wrote: IMO: You need to do your due diligence. This list is not meant to serve as a substitute for learning the basics of R, which you have clearly not done. Please go through an R tutorial or two (there is even one that ships with R, "An Inroduction to R") before posting further here. There are many good ones online, of course. Here is one compendium, but a simple search will find many more: https://support.posit.co/hc/en-us/articles/200552336-Getting-Help-with-R It has been a long time since I looked at R and I thought at least my second Q was something reasonable to ask the list? Anyway now that I need to use R again, the basics should come back to me I hope - but I will check out the tutorials again in any case . . Thanks to Uwe as well (very nice!), Phil. On Tue, Jun 20, 2023 at 8:38 AM Philip Rhoades via R-help wrote: People, I am assuming that what I want to do is easier in R than say Ruby. I want to do what the Subject says ie multiply the cells in the same position of two vectors (A and B) to give a result in the same position in a third vector (C) BUT: - The values in the cells of A and B are floats between 0.0 and 1.0 or NULL - If there is a NULL in the multiplication, then the result in the cell for C is also a NULL - If there is a value less than (say) 0.01 in the multiplication, then the result in the cell for C is 0.0 Any suggestions appreciated! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] OK, next Q - a sort of factorial on a vector
Ivan, On 2023-06-21 03:32, Ivan Krylov wrote: В Wed, 21 Jun 2023 03:13:52 +1000 Philip Rhoades via R-help пишет: This: !(1,2,3,4,5) would give this: (2,3,4,5, 6,8,10, 12,15, 20) Do you mean taking a product of every element of the vector with all following vector elements? A relatively straightforward way would be (given your vector stored in `x`): unlist(lapply(seq_along(x), function(i) x[i] * x[-(1:i)])) Perfect! (I'm sure it could be golfed further.) I will look at Sarah's suggestion too. and this: !(1,2,NA,4,5) would give this: (2,4,5, 8,10, 20) The previous solution seems to give your vector interspersed a bunch of NAs, so one way to continue would be to filter it using v[!is.na(v)]. Exactly! Thanks people - it would have taken forever to work that out myself (it has been decades since I looked at R). Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] OK, next Q - a sort of factorial on a vector
vf <- function(x){
o <- outer(x, x)
as.vector(na.omit(o[lower.tri(o)]))
}
vf(1:5)
vf(c(1,2,NA,4,5))
Best,
Uwe Ligges
On 20.06.2023 19:13, Philip Rhoades via R-help wrote:
People,
What I mean is, is there an elegant way to do this:
This:
!(1,2,3,4,5)
would give this:
(2,3,4,5, 6,8,10, 12,15, 20)
and this:
!(1,2,NA,4,5)
would give this:
(2,4,5, 8,10, 20)
?
Thanks!
Phil.
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] OK, next Q - a sort of factorial on a vector
Well, I think this is reasonable elegant, but ymmv. Turning it into a
function and removing NA values is left for you.
> x <- 1:5
> unlist(sapply(seq(1, length(x) - 1), function(i){x[i] * x[seq(i + 1,
> length(x))]}))
[1] 2 3 4 5 6 8 10 12 15 20
>
> x <- c(1, 2, NA, 4, 5)
> unlist(sapply(seq(1, length(x) - 1), function(i){x[i] * x[seq(i + 1,
> length(x))]}))
[1] 2 NA 4 5 NA 8 10 NA NA 20
Sarah
On Tue, Jun 20, 2023 at 1:15 PM Philip Rhoades via R-help
wrote:
>
> People,
>
> What I mean is, is there an elegant way to do this:
>
> This:
>
>!(1,2,3,4,5)
>
> would give this:
>
>(2,3,4,5, 6,8,10, 12,15, 20)
>
> and this:
>
>!(1,2,NA,4,5)
>
> would give this:
>
>(2,4,5, 8,10, 20)
>
> ?
>
> Thanks!
>
> Phil.
> --
> Philip Rhoades
>
> PO Box 896
> Cowra NSW 2794
> Australia
> E-mail: p...@pricom.com.au
>
> __
> R-help@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.
--
Sarah Goslee (she/her)
http://www.numberwright.com
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] OK, next Q - a sort of factorial on a vector
В Wed, 21 Jun 2023 03:13:52 +1000 Philip Rhoades via R-help пишет: > This: > >!(1,2,3,4,5) > > would give this: > >(2,3,4,5, 6,8,10, 12,15, 20) Do you mean taking a product of every element of the vector with all following vector elements? A relatively straightforward way would be (given your vector stored in `x`): unlist(lapply(seq_along(x), function(i) x[i] * x[-(1:i)])) (I'm sure it could be golfed further.) > and this: > >!(1,2,NA,4,5) > > would give this: > >(2,4,5, 8,10, 20) The previous solution seems to give your vector interspersed a bunch of NAs, so one way to continue would be to filter it using v[!is.na(v)]. -- Best regards, Ivan __ R-help@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.
Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
IMO: You need to do your due diligence. This list is not meant to serve as a substitute for learning the basics of R, which you have clearly not done. Please go through an R tutorial or two (there is even one that ships with R, "An Inroduction to R") before posting further here. There are many good ones online, of course. Here is one compendium, but a simple search will find many more: https://support.posit.co/hc/en-us/articles/200552336-Getting-Help-with-R Cheers, Bert even on On Tue, Jun 20, 2023 at 8:38 AM Philip Rhoades via R-help < r-help@r-project.org> wrote: > People, > > I am assuming that what I want to do is easier in R than say Ruby. > > I want to do what the Subject says ie multiply the cells in the same > position of two vectors (A and B) to give a result in the same position > in a third vector (C) BUT: > > - The values in the cells of A and B are floats between 0.0 and 1.0 or > NULL > > - If there is a NULL in the multiplication, then the result in the cell > for C is also a NULL > > - If there is a value less than (say) 0.01 in the multiplication, then > the result in the cell for C is 0.0 > > Any suggestions appreciated! > > Phil. > > -- > Philip Rhoades > > PO Box 896 > Cowra NSW 2794 > Australia > E-mail: p...@pricom.com.au > > __ > R-help@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@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] OK, next Q - a sort of factorial on a vector
People, What I mean is, is there an elegant way to do this: This: !(1,2,3,4,5) would give this: (2,3,4,5, 6,8,10, 12,15, 20) and this: !(1,2,NA,4,5) would give this: (2,4,5, 8,10, 20) ? Thanks! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
avi, On 2023-06-21 01:55, avi.e.gr...@gmail.com wrote: Phil, What have you tried. This seems straightforward enough. Could you clarify what you mean by NULL? I guess in R in would just be an empty cell? - ie NOT a zero. In R, it is common to use NA or a more specific version of it. Ah yes, that would be it I think. So assuming you have two vectors containing floats with some NA, then: C <- A*B Will give you the products one at a time if the lengths are the same. NA times anything is NA. Right - yes that works! - thanks! Your second condition is also simple as you want anything below a threshold to be set to a fixes value. Since you already have C, above, your condition of: threshold <- 0.1 C < threshold The last line returns a Boolean vector you can use to index C to get just the ones you select as TRUE and thus can change: Result <- C[C < threshold] Ah, I see . . And you can of course do all the above as a one-liner. Yes. Is that what you wanted? Exactly except I meant: Result <- C[C > threshold] Thanks! Phil. -Original Message- From: R-help On Behalf Of Philip Rhoades via R-help Sent: Tuesday, June 20, 2023 11:38 AM To: r-help@r-project.org Subject: [R] Multiplying two vectors of the same size to give a third vector of the same size People, I am assuming that what I want to do is easier in R than say Ruby. I want to do what the Subject says ie multiply the cells in the same position of two vectors (A and B) to give a result in the same position in a third vector (C) BUT: - The values in the cells of A and B are floats between 0.0 and 1.0 or NULL - If there is a NULL in the multiplication, then the result in the cell for C is also a NULL - If there is a value less than (say) 0.01 in the multiplication, then the result in the cell for C is 0.0 Any suggestions appreciated! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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@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. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] Multiplying two vectors of the same size to give a third vector of the same size
Phil, What have you tried. This seems straightforward enough. Could you clarify what you mean by NULL? In R, it is common to use NA or a more specific version of it. So assuming you have two vectors containing floats with some NA, then: C <- A*B Will give you the products one at a time if the lengths are the same. NA times anything is NA. Your second condition is also simple as you want anything below a threshold to be set to a fixes value. Since you already have C, above, your condition of: threshold <- 0.1 C < threshold The last line returns a Boolean vector you can use to index C to get just the ones you select as TRUE and thus can change: Result <- C[C < threshold] And you can of course do all the above as a one-liner. Is that what you wanted? -Original Message- From: R-help On Behalf Of Philip Rhoades via R-help Sent: Tuesday, June 20, 2023 11:38 AM To: r-help@r-project.org Subject: [R] Multiplying two vectors of the same size to give a third vector of the same size People, I am assuming that what I want to do is easier in R than say Ruby. I want to do what the Subject says ie multiply the cells in the same position of two vectors (A and B) to give a result in the same position in a third vector (C) BUT: - The values in the cells of A and B are floats between 0.0 and 1.0 or NULL - If there is a NULL in the multiplication, then the result in the cell for C is also a NULL - If there is a value less than (say) 0.01 in the multiplication, then the result in the cell for C is 0.0 Any suggestions appreciated! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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@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] Multiplying two vectors of the same size to give a third vector of the same size
People, I am assuming that what I want to do is easier in R than say Ruby. I want to do what the Subject says ie multiply the cells in the same position of two vectors (A and B) to give a result in the same position in a third vector (C) BUT: - The values in the cells of A and B are floats between 0.0 and 1.0 or NULL - If there is a NULL in the multiplication, then the result in the cell for C is also a NULL - If there is a value less than (say) 0.01 in the multiplication, then the result in the cell for C is 0.0 Any suggestions appreciated! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: p...@pricom.com.au __ R-help@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.
Re: [R] inconsistency in mclapply.....
Dear Ivan,
Yes, you were rightthe native BLAS version of my ubuntu
system is:
Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.10.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.10.0
Updating BLAS with ropenblas(), as you said,is superficial.
Will reverting back to you if stuck againwith mclapply..
A million thanks again...
THanking you,
Yours sincerely,
AKSHAY M KULKKARNI
From: Ivan Krylov
Sent: Sunday, June 18, 2023 12:42 AM
To: akshay kulkarni
Cc: R help Mailing list
Subject: Re: [R] inconsistency in mclapply.
� Sat, 17 Jun 2023 18:54:43 +
akshay kulkarni �:
> 1. I was working on a two core machine just to test the
> code...tomorrow will be switching to a 48 core machine. Should I
> again download the latest openblas from ropenblas() or do you suggest
> testing the native openblas that is bundled in Ubuntu
What's the version of OpenBLAS in the Ubuntu release you are running?
Unless you can see significant improvements regarding your CPU
architecture appearing since the version included in Ubuntu was
released, there's little reason to install a different version
manually. The whole point of a GNU/Linux distro is not having to
compile everything yourself. Ubuntu's build of OpenBLAS contains
multiple copies of the code targeted at different processors, including
yours.
> 2. How do you pass the version of openblas to be installed with
> ropenblas()? The full file name? or just something like this:
> libopenblas_skylakexp-r0.3.23.so ?
It looks like this function accepts the names of git tags in the
official OpenBLAS Git repository, but it's really the job of the
package maintainer to document important arguments like this one
properly. You can call bug.report(package = 'ropenblas') or write an
e-mail to maintainer('ropenblas') or locate the author's GitHub and ask
a question there.
--
Best regards,
Ivan
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