[R] sequential input script dataframe process functionality

[William Dunlap]

> testdataextract1<-switch(menu(c(unique(levels(testdata[,1]))),graphics=FALSE,title='Select something'))

The switch function does not work the way you are expecting it to.
Read help("switch") and read the introduction to R that comes with R.

You probably want to use the output of menu() to extract a row of
testdata with testdata[outputOfMenu,].  (How could testdataextract1
contain anything in the 2nd or 3rd columns of testdata if the
expression producing testdataextract1 does not contain any reference
to that column?)


Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Sat, Sep 6, 2014 at 6:14 AM,  <rl at openmailbox.org> wrote:
> On 2014-09-05 09:40, rl at openmailbox.org wrote:
>>
>> Subscribers,
>>
>> Could someone please indicate correct terminology and relevant manual
>> sections to achieve the following conceptual workflow, to create a
>> script to select sequentially parts of a dataframe:
>>
>>> "Welcome to this R script program"
>>> Select level number below of variable 'X'
>>
>> [1]
>> [2]
>> [3]
>>>
>>> 3
>>> Select level number below of variable 'Y'
>>
>> [1]
>> [2]
>>>
>>> 1
>>> Summary
>>
>> X, [2] 'descriptive text A for level 3 selected'
>> [1] 'descriptive text B for level 1 selected'
>>>
>>> Display graph? Y/N
>>> y
>>> [specific selected script activated, graph displayed]
>>
>>
>> Thanks in advance.
>>
>> --
>> N.B. digest mode subscriber; please cc message.
>
>
> For a test csv file:
>
> variablea,variableb,variablec
> "text test1","other textx",100
> "text test2","other texty",200
> "text test3","other textz",400
>
> Tried the following:
>
> testdata<-read.csv('test.csv')
> testdataextract1<-switch(menu(c(unique(levels(testdata[,1]))),graphics=FALSE,title='Select
> something'))
>
> Select something
>
> 1: text test1
> 2: text test2
> 3: text test3
>
> Selection: 1
>>
>> testdataextract1
>
> NULL
>
> The requested output is:
>
> "text test1","other textx",100
>
> Why is the result 'NULL'?
>
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