R help - Jul 2013 - Deleting specific rows from a dataframe

I have a data frame like shown below

  sample1 sample2 sample3 sample4 sample5  a P P I P P  b P A P P A  c P P P
P P  d P P P P P  e M P M A P  f P P P P P  g P P P A P  h P P P P P

I want to keep only those rows which have all "P" across all the
columns.

Since the matrix is large (about 20,000 rows), I cannot do it in excel

Any special function that i can use?
-- 
*Chirag Gupta*

	[[alternative HTML version deleted]]

Hi,
If I understand it correctly,
df1<- read.table(text="
sample1 sample2 sample3 sample4 sample5? 
?a P P I P P
?b P A P P A
?c P P P P P
?d P P P P P
?e M P M A P
?f P P P P P
?g P P P A P
?h P P P P P
",sep="",header=TRUE,stringsAsFactors=FALSE)
df1[rowSums(df1=="P")==ncol(df1),]
#? sample1 sample2 sample3 sample4 sample5
#c?????? P?????? P?????? P?????? P?????? P
#d?????? P?????? P?????? P?????? P?????? P
#f ????? P?????? P?????? P?????? P?????? P
#h?????? P?????? P?????? P?????? P?????? P
A.K.



----- Original Message -----
From: Chirag Gupta <cxg040 at email.uark.edu>
To: r-help at r-project.org
Cc: 
Sent: Monday, July 15, 2013 9:10 PM
Subject: [R] Deleting specific rows from a dataframe

I have a data frame like shown below

? sample1 sample2 sample3 sample4 sample5? a P P I P P? b P A P P A? c P P P
P P? d P P P P P? e M P M A P? f P P P P P? g P P P A P? h P P P P P

I want to keep only those rows which have all "P" across all the
columns.

Since the matrix is large (about 20,000 rows), I cannot do it in excel

Any special function that i can use?
-- 
*Chirag Gupta*

??? [[alternative HTML version deleted]]

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