@vi@e@gross m@iii@g oii gm@ii@com
2023-Jun-20 15:55 UTC
[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 <r-help-bounces at r-project.org> On Behalf Of Philip Rhoades via R-help Sent: Tuesday, June 20, 2023 11:38 AM To: r-help at 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: phil at pricom.com.au ______________________________________________ R-help at 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
2023-Jun-20 17:04 UTC
[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.gross at 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 <r-help-bounces at r-project.org> On Behalf Of Philip Rhoades > via > R-help > Sent: Tuesday, June 20, 2023 11:38 AM > To: r-help at 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: phil at pricom.com.au > > ______________________________________________ > R-help at 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 at 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: phil at pricom.com.au