May I ask why:

count_by_class <- with(dat, ave(numeric(length(basel_
asset_class)), basel_asset_class, FUN=length))

should not be more simply done as:

count_by_class <- with(dat, ave(basel_asset_class, basel_asset_class,
FUN=length))

?

-- Bert


On Thu, Oct 17, 2013 at 12:36 PM, William Dunlap <wdunlap@tibco.com> wrote:

> > What I need is to select only those records for which there are more
> than two default
> > frequencies (defa_frequency),
>
> Here is one way.  There are many others:
>    > dat <- data.frame( # slightly less trivial example
>         basel_asset_class=c(4,8,8,8,74,3,74),
>         defa_frequency=(1:7)/8)
>    > count_by_class <- with(dat, ave(numeric(length(basel_asset_class)),
> basel_asset_class, FUN=length))
>    > cbind(dat, count_by_class) # see what we just computed
>      basel_asset_class defa_frequency count_by_class
>    1                 4          0.125              1
>    2                 8          0.250              3
>    3                 8          0.375              3
>    4                 8          0.500              3
>    5                74          0.625              2
>    6                 3          0.750              1
>    7                74          0.875              2
>    > mydat[count_by_class>1, ] # I think this is what you are asking for
>      basel_asset_class defa_frequency
>    2                 8          0.250
>    3                 8          0.375
>    4                 8          0.500
>    5                74          0.625
>    7                74          0.875
>
> Bill Dunlap
> Spotfire, TIBCO Software
> wdunlap tibco.com
>
>
> > -----Original Message-----
> > From: r-help-bounces@r-project.org [mailto:r-help-bounces@r-project.org]
> On Behalf
> > Of Katherine Gobin
> > Sent: Thursday, October 17, 2013 11:05 AM
> > To: Bert Gunter
> > Cc: r-help@r-project.org
> > Subject: Re: [R] Subseting a data.frame
> >
> > Correction. (2nd para first three lines)
> >
> > Pl read following line
> >
> > What I need is to select only those records for which there are more
> than two default
> > frequencies (defa_frequency), Thus, there is only one default frequency
> = 0.150 w.r.t
> > basel_asset_class = 4 whereas there are default frequencies w.r.t. basel
> aseet class 4,
> >
> >
> > as
> >
> > What I need is to select only those records for which there are more
> than two default
> > frequencies (defa_frequency), Thus, there is only one default frequency
> = 0.150 w.r.t
> > basel_asset_class = 4 whereas there are THREE default frequencies w.r.t.
> basel aseet
> > class 8,
> >
> >
> >
> > I alpologize for the incovenience.
> >
> > Regards
> >
> > KAtherine
> >
> >
> >
> >
> >
> >
> >
> >
> > On , Katherine Gobin <katherine_gobin@yahoo.com> wrote:
> >
> >  I am sorry perhaps  was not able to put the question properly. I am not
> looking for the
> > subset of the data.frame where the basel_asset_class is > 2. I do agree
> that would have
> > been a basic requirement. Let me try to put the question again.
> >
> > I have a data frame as
> >
> > mydat = data.frame(basel_asset_class = c(4, 8, 8 ,8), defa_frequency =
> c(0.15, 0.07, 0.03,
> > 0.001))
> >
> > # Please note I have changed the basel_asset_class to 4 from 2, to avoid
> confusion.
> >
> > > mydat
> >   basel_asset_class defa_frequency
> > 1                 4          0.150
> > 2                 8          0.070
> > 3                 8          0.030
> > 4                 8          0.001
> >
> >
> >
> > This is just an representative example. In reality, I may have no of
> basel asset classes. 4, 8
> > etc are the IDs can be anything thus I cant hard code it as subset(mydat,
> > mydat$basel_asset_class > 2).
> >
> >
> > What I need is to select only those records for which there are more
> than two default
> > frequencies (defa_frequency), Thus, there is only one default frequency
> = 0.150 w.r.t
> > basel_asset_class = 4 whereas there are default frequencies w.r.t. basel
> aseet class 4,
> > similarly there could be another basel asset class having say 5 default
> frequncies. Thus, I
> > need to take subset of the data.frame s.t. the no of corresponding
> defa_frequencies is
> > greater than 2.
> >
> > The idea is we try to fit exponential curve Y = A exp( BX ) for each of
> the basel asset
> > classes and to estimate values of A and B, mathematically one needs to
> have at least two
> > values of X.
> >
> > I hope I may be able to express my requirement. Its not that I need the
> subset of mydat
> > s.t. basel asset class is > 2 (now 4 in revised example), but sbuset
> s.t. no of default
> > frequencies is greater than or equal to 2. This 2 is not same as basel
> asset class 2.
> >
> > Kindly guide
> >
> > With warm regards
> >
> > Katherine Gobin
> >
> >
> >
> >
> > On Thursday, 17 October 2013 9:33 PM, Bert Gunter <
> gunter.berton@gene.com> wrote:
> >
> > "Kindly guide" ...
> >
> > This is a very basic question, so the kindest guide I can give is to
> read an Introduction to R
> > (ships with R) or a R web tutorial of your choice so that you can learn
> how R works
> > instead of posting to this list.
> >
> > Cheers,
> > Bert
> >
> >
> >
> >
> > On Wed, Oct 16, 2013 at 11:55 PM, Katherine Gobin <
> katherine_gobin@yahoo.com>
> > wrote:
> >
> > Dear Forum,
> > >
> > >I have a data frame as
> > >
> > >mydat = data.frame(basel_asset_class = c(2, 8, 8 ,8), defa_frequency =
> c(0.15, 0.07,
> > 0.03, 0.001))
> > >
> > >> mydat
> > >  basel_asset_class defa_frequency
> > >1                 2          0.150
> > >2                 8          0.070
> > >3                 8          0.030
> > >4                 8          0.001
> > >
> > >
> > >I need to get the subset of this data.frame where no of records for the
> given
> > basel_asset_class is > 2, i.e. I need to obtain subset of above
> data.frame as (since there
> > is only 1 record, against basel_asset_class = 2, I want to filter it)
> > >
> > >> mydat_a
> > >  basel_asset_class defa_frequency
> > >1                 8          0.070
> > >2                 8          0.030
> > >3                 8          0.001
> > >
> > >Kindly guide
> > >
> > >Katherine
> > >        [[alternative HTML version deleted]]
> > >
> > >
> > >______________________________________________
> > >R-help@r-project.org mailing list
> > >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.
> > >
> > >
> >
> >
> > --
> >
> > Bert Gunter
> > Genentech Nonclinical Biostatistics
> >
> > (650) 467-7374
> >       [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> 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.
>



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

(650) 467-7374

	[[alternative HTML version deleted]]

