[R] sequential input script dataframe process functionality

[William Dunlap]

d <- data.frame(Choices=c("One","Two","One","Three"), X=1:4)
i <- 1 # possible output of menu(unique(d$Choices))
d[ d$Choices[i] == d$Choices, ]
#  Choices X
#1     One 1
#3     One 3

I believe this sort of thing is covered in the Introduction to R pdf
that comes with R.  It is worth reading.

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Mon, Sep 8, 2014 at 8:13 AM,  <rl at openmailbox.org> wrote:
> On Mon, 8 Sep 2014 07:55:23 -0700
> William Dunlap <wdunlap at tibco.com> wrote:
>
>> Again, feed the output of menu() directly into "[".  Do not use
>> switch(). Bill Dunlap
>
>
> The function was changed to:
>
> testdataextract1<-function (testdata) {
> selectionresult<-menu(c(unique(levels(testdata[,1]))),graphics=FALSE,title='Select
> something') return (testdata[selectionresult,])
> }
> testdataextract1(testdata)
>
>> testdataextract1(testdata)
>
> Select something
>
> 1: text test1
> 2: text test2
> 3: text test3
>
> Selection: 2
>    variablea   variableb variablec
> 2 text test2 other texty       200
>
> However, how to adjust the function 'return' so that _all_ values that
> match the selected value from the menu are returned (as below)?
>
>>>
>>> Although the menu must show only unique values to be chosen, the
>>> resultant output must show all values that match the chosen value in
>>> this example:
>>>
>>> text test2 other texty       200
>>> text test2 other texty       700
>>> text test2 other texty       300
>>> text test2 other texty       250