Re: [R] Select part of character row name in a data frame

[Francesca PANCOTTO]

I did not need to select the whole character sentence, otherwise I would know 
how to do it.. from basic introduction to R as you suggest.
Grep works perfectly.

f.

--
Francesca Pancotto, PhD
> Il giorno 19 ott 2017, alle ore 18:01, Jeff Newmiller 
>  ha scritto:
> 
> (Re-)read the discussion of indexing (both `[` and `[[`) and be sure to get 
> clear on the difference between matrices and data frames in the Introduction 
> to R document that comes with R. There are many ways to create numeric 
> vectors, character vectors, and logical vectors that can then be used as 
> indexes, including the straightforward way:
> 
> df[ c(
> "Unique to strat  ",
> "Unique to strat:crt.dummy ",
> "Common to strat, and crt.dummy ",
> "Common to strat, and gender ",
> "Common to strat, and age ") ,]
> -- 
> Sent from my phone. Please excuse my brevity.
> 
> On October 19, 2017 3:14:53 AM PDT, Francesca PANCOTTO 
>  wrote:
>> Thanks a lot, so simple so efficient!
>> 
>> I will study more the grep command I did not know.
>> 
>> Thanks!
>> 
>> 
>> Francesca Pancotto
>> 
>>> Il giorno 19 ott 2017, alle ore 12:12, Enrico Schumann
>>  ha scritto:
>>> 
>>> df[grep("strat", row.names(df)), ]
>> 
>> 
>>  [[alternative HTML version deleted]]
>> 
>> __
>> R-help@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.

__
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Re: [R] Select part of character row name in a data frame

[Jeff Newmiller]

(Re-)read the discussion of indexing (both `[` and `[[`) and be sure to get 
clear on the difference between matrices and data frames in the Introduction to 
R document that comes with R. There are many ways to create numeric vectors, 
character vectors, and logical vectors that can then be used as indexes, 
including the straightforward way:

df[ c(
"Unique to strat  ",
"Unique to strat:crt.dummy ",
"Common to strat, and crt.dummy ",
"Common to strat, and gender ",
"Common to strat, and age ") ,]
-- 
Sent from my phone. Please excuse my brevity.

On October 19, 2017 3:14:53 AM PDT, Francesca PANCOTTO  
wrote:
>Thanks a lot, so simple so efficient!
>
>I will study more the grep command I did not know.
>
>Thanks!
>
>
>Francesca Pancotto
>
>> Il giorno 19 ott 2017, alle ore 12:12, Enrico Schumann
> ha scritto:
>> 
>>  df[grep("strat", row.names(df)), ]
>
>
>   [[alternative HTML version deleted]]
>
>__
>R-help@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.

__
R-help@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.

Re: [R] Select part of character row name in a data frame

[Francesca PANCOTTO]

Thanks a lot, so simple so efficient!

I will study more the grep command I did not know.

Thanks!


Francesca Pancotto

> Il giorno 19 ott 2017, alle ore 12:12, Enrico Schumann 
>  ha scritto:
> 
>  df[grep("strat", row.names(df)), ]


[[alternative HTML version deleted]]

__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Re: [R] Select part of character row name in a data frame

[Enrico Schumann]

Quoting Francesca PANCOTTO :


Dear R contributors,

I have a problem in selecting in an efficient way, rows of a data  
frame according to a condition,

which is a part of a row name of the table.

The data frame is made of 64 rows and 2 columns, but the row names  
are very long but I need to select them according to a small part of  
it and perform calculations on the subsets.


This is the example:

X   Y
"Unique to strat  "   
  0.048228.39
"Unique to crt.dummy" 
  0.044125.92
"Unique to gender   " 
  0.0159 9.36
"Unique to age   "
  0.083949.37
"Unique to gg_right1  "   
  0.0019 1.10
"Unique to strat:crt.dummy "  
  0.068940.54
"Common to strat, and crt.dummy " 
 -0.0392   -23.09
"Common to strat, and gender "
 -0.0031-1.84
"Common to crt.dummy, and gender "
  0.0038 2.21
"Common to strat, and age "   
  0.0072 4.21


X and Y are the two columns of variables, while “Unique to strat”,  
are the row names. I am interested to select for example those rows
whose name contains “strat” only. It would be very easy if these  
names were simple, but they are not and involve also spaces.
I tried with select matches from dplyr but works for column names  
but I did not find how to use it on row names, which are of course  
character values.


Thanks for any help you can provide.

--
Francesca Pancotto, PhD



Use ?grep or ?grepl:

df[grep("strat", row.names(df)), ]

(in which 'df' is your data frame)


--
Enrico Schumann
Lucerne, Switzerland
http://enricoschumann.net

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