Re: [R] remove rows of a matrix by part of its row name

2018-05-22 Thread William Dunlap via R-help 
I think it is simpler to use !grepl() instead of -grep() here, since
subscripting with logicals works properly when there are no matches.
Also, since mat is a matrix, add the argument drop=FALSE so the
result is a matrix when all but one rows are omitted.  E.g.,

> mat <- matrix(1:6, nrow=3, ncol=2,
dimnames=list(c("One","Two","Three"),c("A","B")))
> str(mat[ -grep("T", rownames(mat)), ]) # bad, not a matrix if only one
row wanted
 Named int [1:2] 1 4
 - attr(*, "names")= chr [1:2] "A" "B"
> str(mat[ -grep("X", rownames(mat)), ]) # bad, zero-row matrix if no
unwanted rows
 int[0 , 1:2]
 - attr(*, "dimnames")=List of 2
  ..$ : NULL
  ..$ : chr [1:2] "A" "B"
> str(mat[ !grepl("T", rownames(mat)), , drop=FALSE]) # good, one row
matrix if only one row wanted
 int [1, 1:2] 1 4
 - attr(*, "dimnames")=List of 2
  ..$ : chr "One"
  ..$ : chr [1:2] "A" "B"
> str(mat[ !grepl("X", rownames(mat)), , drop=FALSE]) # good, entire matrix
is no unwanted rows
 int [1:3, 1:2] 1 2 3 4 5 6
 - attr(*, "dimnames")=List of 2
  ..$ : chr [1:3] "One" "Two" "Three"
  ..$ : chr [1:2] "A" "B"



Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Tue, May 22, 2018 at 4:34 AM, Rui Barradas  wrote:

> Hello,
>
> Use grep to get the row indices and then subset with a *negative* index to
> remove those rows.
>
> rn <- scan(what = character(), text = "
> 70/556
> 71.1/280
> 72.1/556
> 72.1/343
> 73.1/390
> 73.1/556
> ")
>
> mat <- matrix(rnorm(6*6), nrow = 6)
> row.names(mat) <- rn
>
> inx <- grep("73\\.", row.names(mat))
>
> new_mat <- mat[-inx, ]
> new_mat
>
>
> Hope this helps,
>
> Rui Barradas
>
>
> On 5/22/2018 11:48 AM, Ahmed Serag wrote:
>
>> Dear R-experts,
>>
>>
>> How can I remove a certain feature or observation by a part of its name.
>> To be clear, I have a matrix with 766 observations as a rows. The row names
>> are like this
>>
>> 70/556
>> 71.1/280
>> 72.1/556
>> 72.1/343
>> 73.1/390
>> 73.1/556
>> Now I would like to remove all the rows that contain the text 73.1
>>
>> Any ideas or suggestion please ?
>>
>>
>> Regards
>>
>>
>>
>>
>> **
>>
>> Ahmed Serag
>>
>> Analytical Chemistry Department
>>
>> Faculty of Pharmacy
>>
>> Al-Azhar University
>>
>> Cairo
>>
>> Egypt
>>
>> [[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/posti
>> ng-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/posti
> ng-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

[[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.

Re: [R] remove rows of a matrix by part of its row name

2018-05-22 Thread Ahmed Serag 

Thanks a lot. The code works great.

Regards

Ahmed

**

Ahmed Serag

Analytical Chemistry Department

Faculty of Pharmacy

Al-Azhar University

Cairo

Egypt



From: Rui Barradas 
Sent: Tuesday, May 22, 2018 2:16 PM
To: Ahmed Serag; R-help@r-project.org
Subject: Re: [R] remove rows of a matrix by part of its row name

Hello,

Please always cc the list.

As for the question, yes, it does. If you want to remove just the ones
with exactly 73.1 use the pattern

grep("^73\\.1$", etc)

Explanation:

Beginning of string: ^
End of string: $
Escape special characters: \\ (needed because the period is a special
character.)

Hope this helps,

Rui Barradas

On 5/22/2018 12:50 PM, Ahmed Serag wrote:
> Thank you Mr. Barradas. The code works great. Unfortunately I have also
> some labeles with
>
>
> 173.1
>
> 273.1
>
>
> the grep script remove them also ?
>
> Any ideas Plz, Thanks again
>
>
> 
>
> *Ahmed Serag*
>
> /Analytical Chemistry Department/
>
> /Faculty of Pharmacy/
>
> /Al-Azhar University/
>
> /Cairo/
>
> /Egypt/
>
>
>
> 
> *From:* Rui Barradas 
> *Sent:* Tuesday, May 22, 2018 1:34 PM
> *To:* Ahmed Serag; r-help@r-project.org
> *Subject:* Re: [R] remove rows of a matrix by part of its row name
> Hello,
>
> Use grep to get the row indices and then subset with a *negative* index
> to remove those rows.
>
> rn <- scan(what = character(), text = "
> 70/556
> 71.1/280
> 72.1/556
> 72.1/343
> 73.1/390
> 73.1/556
> ")
>
> mat <- matrix(rnorm(6*6), nrow = 6)
> row.names(mat) <- rn
>
> inx <- grep("73\\.", row.names(mat))
>
> new_mat <- mat[-inx, ]
> new_mat
>
>
> Hope this helps,
>
> Rui Barradas
>
> On 5/22/2018 11:48 AM, Ahmed Serag wrote:
>> Dear R-experts,
>>
>>
>> How can I remove a certain feature or observation by a part of its name. To 
>> be clear, I have a matrix with 766 observations as a rows. The row names are 
>> like this
>>
>> 70/556
>> 71.1/280
>> 72.1/556
>> 72.1/343
>> 73.1/390
>> 73.1/556
>> Now I would like to remove all the rows that contain the text 73.1
>>
>> Any ideas or suggestion please ?
>>
>>
>> Regards
>>
>>
>>
>>
>> **
>>
>> Ahmed Serag
>>
>> Analytical Chemistry Department
>>
>> Faculty of Pharmacy
>>
>> Al-Azhar University
>>
>> Cairo
>>
>> Egypt
>>
>>[[alternative HTML version deleted]]
>>
>> __
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help

thz.ch/mailman/listinfo/r-help>
stat.ethz.ch
The main R mailing list, for announcements about the development of R and the 
availability of new code, questions and answers about problems and solutions 
using R, enhancements and patches to the source code and documentation of R, 
comparison and compatibility with S and S-plus, and for the posting of nice 
examples and benchmarks.




> 
> stat.ethz.ch
> The main R mailing list, for announcements about the development of R
> and the availability of new code, questions and answers about problems
> and solutions using R, enhancements and patches to the source code and
> documentation of R, comparison and compatibility with S and S-plus, and
> for the posting of nice examples and benchmarks.
>
>
>
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>

[[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.

Re: [R] remove rows of a matrix by part of its row name

2018-05-22 Thread Rui Barradas 

Hello,

Please always cc the list.

As for the question, yes, it does. If you want to remove just the ones 
with exactly 73.1 use the pattern


grep("^73\\.1$", etc)

Explanation:

Beginning of string: ^
End of string: $
Escape special characters: \\ (needed because the period is a special 
character.)


Hope this helps,

Rui Barradas

On 5/22/2018 12:50 PM, Ahmed Serag wrote:
Thank you Mr. Barradas. The code works great. Unfortunately I have also 
some labeles with



173.1

273.1


the grep script remove them also ?

Any ideas Plz, Thanks again




*Ahmed Serag*

/Analytical Chemistry Department/

/Faculty of Pharmacy/

/Al-Azhar University/

/Cairo/

/Egypt/




*From:* Rui Barradas 
*Sent:* Tuesday, May 22, 2018 1:34 PM
*To:* Ahmed Serag; r-help@r-project.org
*Subject:* Re: [R] remove rows of a matrix by part of its row name
Hello,

Use grep to get the row indices and then subset with a *negative* index
to remove those rows.

rn <- scan(what = character(), text = "
70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
")

mat <- matrix(rnorm(6*6), nrow = 6)
row.names(mat) <- rn

inx <- grep("73\\.", row.names(mat))

new_mat <- mat[-inx, ]
new_mat


Hope this helps,

Rui Barradas

On 5/22/2018 11:48 AM, Ahmed Serag wrote:

Dear R-experts,


How can I remove a certain feature or observation by a part of its name. To be 
clear, I have a matrix with 766 observations as a rows. The row names are like 
this

70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
Now I would like to remove all the rows that contain the text 73.1

Any ideas or suggestion please ?


Regards




**

Ahmed Serag

Analytical Chemistry Department

Faculty of Pharmacy

Al-Azhar University

Cairo

Egypt

    [[alternative HTML version deleted]]

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
R-help -- Main R Mailing List: Primary help - Homepage - SfS 


stat.ethz.ch
The main R mailing list, for announcements about the development of R 
and the availability of new code, questions and answers about problems 
and solutions using R, enhancements and patches to the source code and 
documentation of R, comparison and compatibility with S and S-plus, and 
for the posting of nice examples and benchmarks.





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] remove rows of a matrix by part of its row name

2018-05-22 Thread Rui Barradas 

Hello,

Use grep to get the row indices and then subset with a *negative* index 
to remove those rows.


rn <- scan(what = character(), text = "
70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
")

mat <- matrix(rnorm(6*6), nrow = 6)
row.names(mat) <- rn

inx <- grep("73\\.", row.names(mat))

new_mat <- mat[-inx, ]
new_mat


Hope this helps,

Rui Barradas

On 5/22/2018 11:48 AM, Ahmed Serag wrote:

Dear R-experts,


How can I remove a certain feature or observation by a part of its name. To be 
clear, I have a matrix with 766 observations as a rows. The row names are like 
this

70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
Now I would like to remove all the rows that contain the text 73.1

Any ideas or suggestion please ?


Regards




**

Ahmed Serag

Analytical Chemistry Department

Faculty of Pharmacy

Al-Azhar University

Cairo

Egypt

[[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.

[R] remove rows of a matrix by part of its row name

2018-05-22 Thread Ahmed Serag 
Dear R-experts,


How can I remove a certain feature or observation by a part of its name. To be 
clear, I have a matrix with 766 observations as a rows. The row names are like 
this

70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
Now I would like to remove all the rows that contain the text 73.1

Any ideas or suggestion please ?


Regards




**

Ahmed Serag

Analytical Chemistry Department

Faculty of Pharmacy

Al-Azhar University

Cairo

Egypt

[[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.