Application of "merge" and "within"

Notice that within-group processing is intended. I'd try
first <- function(x)x[1]
s  <- within(q, {bl <- ave(b, paste(G,a), FUN=first); db <- b - bl})
Or perhaps

q <- within(q, Ga <- paste(G,a))
tbl <- with(q, tapply(b, Ga, first))
s <- within(q, {bl <- tbl[Ga]; db <- b - bl})

-pd

On 27/05/2016 7:00 PM, Santosh wrote:
Dear Rxperts!

Is there a way to compute relative values.. using within().. function?

Any assistance/suggestions are highly welcome!!
Thanks again,
Santosh...
___________________________________________________________________
A sample dataset and the computation "outside" within()  function is shown..

q <- data.frame(GL = rep(paste("G",1:3,sep = ""),each = 50),
               G  = rep(1:3,each = 50),
               D = rep(paste("D",1:5,sep = ""),each = 30),
               a = rep(1:15,each = 10),
               t = rep(seq(10),15),
               b = round(runif(150,10,20)))
r <- subset(q,!duplicated(paste(G,a)),sel=c(G,a,b))
names(r)[3] <- "bl"
s <- merge(q,r)
s$db <- s$b-s$bl

head(s,5)
   G  a GL  D  t  b bl db
1   1  1 G1 D1  1 13 13  0
2   1  1 G1 D1  2 16 13  3
3   1  1 G1 D1  3 19 13  6
4   1  1 G1 D1  4 12 13 -1
5   1  1 G1 D1  5 19 13  6
Just use

s <- within(s, db <- b - bl)

Duncan Murdoch

______________________________________________
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.

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
Thanks so much.. I will try that.. and keep you posted..

on a different note.. using the above examples.. after adding a new column
is blank.. summarizing a null column causes errors.. (like min(NULL) or
min(NA) etc.. to avoid that I was trying the following code..

within(q, as.data.frame(as.matrix(apply($DATA,2,function(x)
{require(gtools);x1 <- ifelse(invalid(x),0,x);return(x1)}))))

For some reason, the above code is not working.. any ideas on converting
NAs/blanks to 0 using apply in within? or any other similar method?

Thanks so much.. I appreciate your help!!

Regards,
Santosh

Notice that within-group processing is intended. I'd try

first <- function(x)x[1]
s  <- within(q, {bl <- ave(b, paste(G,a), FUN=first); db <- b - bl})
Or perhaps

q <- within(q, Ga <- paste(G,a))
tbl <- with(q, tapply(b, Ga, first))
s <- within(q, {bl <- tbl[Ga]; db <- b - bl})

-pd

On 28 May 2016, at 22:53 , Duncan Murdoch <murdoch.duncan at gmail.com>
wrote:

On 27/05/2016 7:00 PM, Santosh wrote:
Dear Rxperts!

Is there a way to compute relative values.. using within().. function?

Any assistance/suggestions are highly welcome!!
Thanks again,
Santosh...
___________________________________________________________________
A sample dataset and the computation "outside" within()  function is
shown..
q <- data.frame(GL = rep(paste("G",1:3,sep = ""),each = 50),
               G  = rep(1:3,each = 50),
               D = rep(paste("D",1:5,sep = ""),each = 30),
               a = rep(1:15,each = 10),
               t = rep(seq(10),15),
               b = round(runif(150,10,20)))
r <- subset(q,!duplicated(paste(G,a)),sel=c(G,a,b))
names(r)[3] <- "bl"
s <- merge(q,r)
s$db <- s$b-s$bl

head(s,5)
   G  a GL  D  t  b bl db
1   1  1 G1 D1  1 13 13  0
2   1  1 G1 D1  2 16 13  3
3   1  1 G1 D1  3 19 13  6
4   1  1 G1 D1  4 12 13 -1
5   1  1 G1 D1  5 19 13  6
Just use

s <- within(s, db <- b - bl)

Duncan Murdoch

______________________________________________
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.

--
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

Hi Peter and others..
In the code from Peter..(reproduced below for convenience..)
....
first <- function(x)x[1]
s  <- within(q, {bl <- ave(b, paste(G,a), FUN=first); db <- b - bl})
....

is there a reason behind that 'ave' used in the above code?
is there way to perform a multi-column sort in within?

Thanks so much..
Santosh

Notice that within-group processing is intended. I'd try

first <- function(x)x[1]
s  <- within(q, {bl <- ave(b, paste(G,a), FUN=first); db <- b - bl})
Or perhaps

q <- within(q, Ga <- paste(G,a))
tbl <- with(q, tapply(b, Ga, first))
s <- within(q, {bl <- tbl[Ga]; db <- b - bl})

-pd

On 28 May 2016, at 22:53 , Duncan Murdoch <murdoch.duncan at gmail.com>
wrote:

On 27/05/2016 7:00 PM, Santosh wrote:
Dear Rxperts!

Is there a way to compute relative values.. using within().. function?

Any assistance/suggestions are highly welcome!!
Thanks again,
Santosh...
___________________________________________________________________
A sample dataset and the computation "outside" within()  function is
shown..
q <- data.frame(GL = rep(paste("G",1:3,sep = ""),each = 50),
               G  = rep(1:3,each = 50),
               D = rep(paste("D",1:5,sep = ""),each = 30),
               a = rep(1:15,each = 10),
               t = rep(seq(10),15),
               b = round(runif(150,10,20)))
r <- subset(q,!duplicated(paste(G,a)),sel=c(G,a,b))
names(r)[3] <- "bl"
s <- merge(q,r)
s$db <- s$b-s$bl

head(s,5)
   G  a GL  D  t  b bl db
1   1  1 G1 D1  1 13 13  0
2   1  1 G1 D1  2 16 13  3
3   1  1 G1 D1  3 19 13  6
4   1  1 G1 D1  4 12 13 -1
5   1  1 G1 D1  5 19 13  6
Just use

s <- within(s, db <- b - bl)

Duncan Murdoch

______________________________________________
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.

--
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