R devel - Feb 2020 - function(x) !is.na(x) & x "is_true(.)" etc. was: [R] How to index..

Dear William,
Thank you so much.

I am quiet new in R. I would like to do this based on another repeated
variables.

For example:
a<-c(1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2)
d<-c(NA, 0, 0, 0, 8, 0, 577, 69, 0, NA, 0, 0, 0, 8, 0, 577, 69, 0)
the outcome I want is :
y<-c(1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 1, 1 ,1, 1 ,1, 2, 3, 3)

Therefore, I would like to create y based on the variable a. once variable a has
changed, the index will start from 1 again. I wrote a for loop, but it did not
give me what I want. Could you please help me again?

Thanks in advance,

Lijun



From: William Dunlap <wdunlap at tibco.com>
Sent: Thursday, 20 February 2020 1:53 AM
To: Lijun Zhao <lijun.zhao at adelaide.edu.au>
Cc: r-help at r-project.org
Subject: Re: [R] How to index the occasions in a vector repeatedly under
condition 1? if not, it will give a new index.

Use cumsum(logicalVector) to increment a counter at the TRUE positions in
logicalVector. .  E.g.,
> d <- c(NA, 0, 0, 0, 8, 0, 577, 69, 0)
> is_true <- function(x) !is.na<http://is.na>(x) & x
> 1 + cumsum( is_true(d >= 15) )
[1] 1 1 1 1 1 1 2 3 3

Some packages have the equivalent of that is_true function, which maps FALSE and
NA to FALSE and TRUE to TRUE.  I don't think core R contains such a
function.

Bill Dunlap
TIBCO Software
wdunlap tibco.com<http://tibco.com>


On Wed, Feb 19, 2020 at 7:08 AM Lijun Zhao <lijun.zhao at
adelaide.edu.au<mailto:lijun.zhao at adelaide.edu.au>> wrote:
Dear all,
Could you please help me how to get the output as I described in the following
example?

x<-c(543,  543,  543,  543,  551 , 551 ,1128 ,1197, 1197)
diff<-x-lag(x)
diff
[1]  NA   0   0   0   8   0 577  69   0

How to index the occasions in x repeatedly if the diff<15? if diff>=15, it
will give a new index.
I want the output be like y.

y<-c(1,1,1,1,1,1,2,3,3)

Thank you so much,

Lijun Zhao (PhD Candidate)
Nutrition and Metabolism
Level 7 SAHMRI
North Terrace
Adelaide 5005
Ph    : +61 8 8128 4898
e-mail: lijun.zhao at adelaide.edu.au<mailto:lijun.zhao at
adelaide.edu.au><mailto:lijun.zhao at adelaide.edu.au<mailto:lijun.zhao
at adelaide.edu.au>> or lijun.zhao at sahmri.com<mailto:lijun.zhao at
sahmri.com><mailto:lijun.zhao at sahmri.com<mailto:lijun.zhao at
sahmri.com>>



        [[alternative HTML version deleted]]

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Hi

If you used diff construction you would not have NA values in beginning

#get rid of NA values
> d[is.na(d)] <- 0
#split d according to a
> d.s <- split(d, a)
# get the result
> lapply(d.s, function(x) cumsum(x>15)+1)
$`1`
[1] 1 1 1 1 1 1 2 3 3

$`2`
[1] 1 1 1 1 1 1 2 3 3
#unlist it
> res <- lapply(d.s, function(x) cumsum(x>15)+1)
> unlist(res)
11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 
 1  1  1  1  1  1  2  3  3  1  1  1  1  1  1  2  3  3 

Cheers
Petr
> -----Original Message-----
> From: R-help <r-help-bounces at r-project.org> On Behalf Of Lijun
Zhao
> Sent: Thursday, February 20, 2020 4:21 AM
> To: William Dunlap <wdunlap at tibco.com>
> Cc: r-help at r-project.org
> Subject: Re: [R] How to index the occasions in a vector repeatedly under
> condition 1? if not, it will give a new index.
> 
> Dear William,
> Thank you so much.
> 
> I am quiet new in R. I would like to do this based on another repeated
variables.
> 
> For example:
> a<-c(1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2)
> d<-c(NA, 0, 0, 0, 8, 0, 577, 69, 0, NA, 0, 0, 0, 8, 0, 577, 69, 0) the
outcome I
> want is :
> y<-c(1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 1, 1 ,1, 1 ,1, 2, 3, 3)
> 
> Therefore, I would like to create y based on the variable a. once variable
a has
> changed, the index will start from 1 again. I wrote a for loop, but it did
not give
> me what I want. Could you please help me again?
> 
> Thanks in advance,
> 
> Lijun
> 
> 
> 
> From: William Dunlap <wdunlap at tibco.com>
> Sent: Thursday, 20 February 2020 1:53 AM
> To: Lijun Zhao <lijun.zhao at adelaide.edu.au>
> Cc: r-help at r-project.org
> Subject: Re: [R] How to index the occasions in a vector repeatedly under
> condition 1? if not, it will give a new index.
> 
> Use cumsum(logicalVector) to increment a counter at the TRUE positions in
> logicalVector. .  E.g.,
> 
> > d <- c(NA, 0, 0, 0, 8, 0, 577, 69, 0)
> > is_true <- function(x) !is.na<http://is.na>(x) & x
> > 1 + cumsum( is_true(d >= 15) )
> [1] 1 1 1 1 1 1 2 3 3
> 
> Some packages have the equivalent of that is_true function, which maps
FALSE
> and NA to FALSE and TRUE to TRUE.  I don't think core R contains such a
> function.
> 
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com<http://tibco.com>
> 
> 
> On Wed, Feb 19, 2020 at 7:08 AM Lijun Zhao
> <lijun.zhao at adelaide.edu.au<mailto:lijun.zhao at
adelaide.edu.au>> wrote:
> Dear all,
> Could you please help me how to get the output as I described in the
following
> example?
> 
> x<-c(543,  543,  543,  543,  551 , 551 ,1128 ,1197, 1197)
> diff<-x-lag(x)
> diff
> [1]  NA   0   0   0   8   0 577  69   0
> 
> How to index the occasions in x repeatedly if the diff<15? if
diff>=15, it
will give
> a new index.
> I want the output be like y.
> 
> y<-c(1,1,1,1,1,1,2,3,3)
> 
> Thank you so much,
> 
> Lijun Zhao (PhD Candidate)
> Nutrition and Metabolism
> Level 7 SAHMRI
> North Terrace
> Adelaide 5005
> Ph    : +61 8 8128 4898
> e-mail:
>
lijun.zhao at adelaide.edu.au<mailto:lijun.zhao at
adelaide.edu.au><mailto:lijun.z
> hao at adelaide.edu.au<mailto:lijun.zhao at adelaide.edu.au>> or
> lijun.zhao at sahmri.com<mailto:lijun.zhao at
sahmri.com><mailto:lijun.zhao at sa
> hmri.com<mailto:lijun.zhao at sahmri.com>>
> 
> 
> 
>         [[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org<mailto: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.
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> 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.

It has isTRUE, but that is not vectorized, and in fact explicitly tests
length==1, so
> isTRUE(c(TRUE,FALSE,NA))
[1] FALSE
> isTRUE(c(TRUE,TRUE, TRUE)) # I thought I thaw a puddycat... ;-)
 [1] FALSE
> Vectorize(isTRUE)(c(TRUE,FALSE,NA))
[1]  TRUE FALSE FALSE

(The latter would be silly as an implementation of is_true, of course.)

-pd
> On 20 Feb 2020, at 04:20 , Lijun Zhao <lijun.zhao at adelaide.edu.au>
wrote:
> 
> 
> Some packages have the equivalent of that is_true function, which maps
FALSE and NA to FALSE and TRUE to TRUE.  I don't think core R contains such
a function.
-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

Diverted from R-help to R-devel,
as I've changed the focus to consider adding new functions to R :
>>>>> peter dalgaard 
>>>>>     on Fri, 21 Feb 2020 10:46:16 +0100 writes:
    > It has isTRUE, but that is not vectorized, and in fact explicitly tests
length==1, so
    >> isTRUE(c(TRUE,FALSE,NA))
    > [1] FALSE
    >> isTRUE(c(TRUE,TRUE, TRUE)) # I thought I thaw a puddycat... ;-)
    > [1] FALSE
    >> Vectorize(isTRUE)(c(TRUE,FALSE,NA))
    > [1]  TRUE FALSE FALSE

    > (The latter would be silly as an implementation of is_true, of course.)

    > -pd

yes... We've had (hidden) functions in the Matrix package for
these, which can still be accelerated (quite a bit for most
arguments), in Matrix/R/Auxiliaries.R (see the R-forge development version :
 https://r-forge.r-project.org/scm/viewvc.php/pkg/Matrix/R/Auxiliaries.R?view=markup&root=matrix
)


## Need to consider NAs ;  "== 0" even works for logical &
complex:
## Note that "!x" is faster than "x == 0", but does not
(yet!) work for complex
## if we did these in C, would gain a factor 2 (or so):
is0  <- function(x) !is.na(x) & x == 0
isN0 <- function(x)  is.na(x) | x != 0
is1  <- function(x) !is.na(x) & x   # also == "isTRUE
componentwise"


{{Note that here  0 <==> FALSE   and  non-0 <==> TRUE , and I
  had preferred the shorter words to the longer ones in the
  Matrix pkg, not the least as '0' is relevant also for
  talking/programming about sparse matrices ..
}}

... and then there are  all* and any* versions of these
functions there , for which I have even written fast C based .Call()s ...

May this be something worth adding to base  for  R 4.0.0
(if only just to entice more users making the effort to switch
 to it in ca. 2 months) ?

Martin



    >> On 20 Feb 2020, at 04:20 , Lijun Zhao <lijun.zhao at
adelaide.edu.au> wrote:
    >> 
    >> 
    >> Some packages have the equivalent of that is_true function, which
maps FALSE and NA to FALSE and TRUE to TRUE.  I don't think core R contains
such a function.

    > -- 
    > Peter Dalgaard, Professor,
    > Center for Statistics, Copenhagen Business School
    > Solbjerg Plads 3, 2000 Frederiksberg, Denmark
    > Phone: (+45)38153501
    > Office: A 4.23
    > Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

    > ______________________________________________
    > 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.

> all.equal(y, ave(d, cumsum(c(TRUE,is_true(diff(a)!=0))),
FUN=function(di)1L+cumsum(is_true(di>15))))
[1] TRUE

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Wed, Feb 19, 2020 at 7:20 PM Lijun Zhao <lijun.zhao at adelaide.edu.au>
wrote:
> Dear William,
>
> Thank you so much.
>
>
>
> I am quiet new in R. I would like to do this based on another repeated
> variables.
>
>
>
> For example:
>
> a<-c(1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2)
>
> d<-c(NA, 0, 0, 0, 8, 0, 577, 69, 0, NA, 0, 0, 0, 8, 0, 577, 69, 0)
>
> the outcome I want is :
>
> y<-c(1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 1, 1 ,1, 1 ,1, 2, 3, 3)
>
>
>
> Therefore, I would like to create y based on the variable a. once variable
> a has changed, the index will start from 1 again. I wrote a for loop, but
> it did not give me what I want. Could you please help me again?
>
>
>
> Thanks in advance,
>
>
>
> Lijun
>
>
>
>
>
>
>
> *From:* William Dunlap <wdunlap at tibco.com>
> *Sent:* Thursday, 20 February 2020 1:53 AM
> *To:* Lijun Zhao <lijun.zhao at adelaide.edu.au>
> *Cc:* r-help at r-project.org
> *Subject:* Re: [R] How to index the occasions in a vector repeatedly
> under condition 1? if not, it will give a new index.
>
>
>
> Use cumsum(logicalVector) to increment a counter at the TRUE positions in
> logicalVector. .  E.g.,
>
>
>
> > d <- c(NA, 0, 0, 0, 8, 0, 577, 69, 0)
>
> > is_true <- function(x) !is.na(x) & x
> > 1 + cumsum( is_true(d >= 15) )
> [1] 1 1 1 1 1 1 2 3 3
>
>
>
> Some packages have the equivalent of that is_true function, which maps
> FALSE and NA to FALSE and TRUE to TRUE.  I don't think core R contains
such
> a function.
>
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
>
>
>
>
> On Wed, Feb 19, 2020 at 7:08 AM Lijun Zhao <lijun.zhao at
adelaide.edu.au>
> wrote:
>
> Dear all,
> Could you please help me how to get the output as I described in the
> following example?
>
> x<-c(543,  543,  543,  543,  551 , 551 ,1128 ,1197, 1197)
> diff<-x-lag(x)
> diff
> [1]  NA   0   0   0   8   0 577  69   0
>
> How to index the occasions in x repeatedly if the diff<15? if
diff>=15, it
> will give a new index.
> I want the output be like y.
>
> y<-c(1,1,1,1,1,1,2,3,3)
>
> Thank you so much,
>
> Lijun Zhao (PhD Candidate)
> Nutrition and Metabolism
> Level 7 SAHMRI
> North Terrace
> Adelaide 5005
> Ph    : +61 8 8128 4898
> e-mail: lijun.zhao at adelaide.edu.au<mailto:lijun.zhao at
adelaide.edu.au> or
> lijun.zhao at sahmri.com<mailto:lijun.zhao at sahmri.com>
>
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>
>
	[[alternative HTML version deleted]]

Hi Peter,
Thank you so much.

Kind regards,

Lijun

-----Original Message-----
From: peter dalgaard <pdalgd at gmail.com>
Sent: Friday, 21 February 2020 8:16 PM
To: Lijun Zhao <lijun.zhao at adelaide.edu.au>
Cc: William Dunlap <wdunlap at tibco.com>; r-help at r-project.org
Subject: Re: [R] How to index the occasions in a vector repeatedly under
condition 1? if not, it will give a new index.

It has isTRUE, but that is not vectorized, and in fact explicitly tests
length==1, so
> isTRUE(c(TRUE,FALSE,NA))
[1] FALSE
> isTRUE(c(TRUE,TRUE, TRUE)) # I thought I thaw a puddycat... ;-)
 [1] FALSE
> Vectorize(isTRUE)(c(TRUE,FALSE,NA))
[1]  TRUE FALSE FALSE

(The latter would be silly as an implementation of is_true, of course.)

-pd
> On 20 Feb 2020, at 04:20 , Lijun Zhao <lijun.zhao at adelaide.edu.au>
wrote:
>
>
> Some packages have the equivalent of that is_true function, which maps
FALSE and NA to FALSE and TRUE to TRUE.  I don't think core R contains such
a function.
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000
Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com