R help - Mar 2007 - replacing all NA's in a dataframe with zeros...

I've seen how to  replace the NA's in a single column with a data frame

*> mydata$ncigs[is.na(mydata$ncigs)]<-0

*But this is just one column... I have thousands of columns (!) that I need
to do this, and I can't figure out a way, outside of the dreaded loop, do
replace all NA's in an entire data frame (all vars) without naming each var
separately. Yikes.

I'm racking my brain on this, seems like I must be staring at the obvious,
but it eludes me. Searches have come up CLOSE, but not quite what I need..

Any pointers?

-- 
---------------------------------------
David L. Van Brunt, Ph.D.
mailto:dlvanbrunt@gmail.com

"If Tyranny and Oppression come to this land, it will be in the guise of
fighting a foreign enemy."
--James Madison

	[[alternative HTML version deleted]]

This should work.
> test.df <- data.frame(x1=c(NA,2,3,NA), x2=c(1,2,3,4), 
> x3=c(1,NA,NA,4))
> test.df
  x1 x2 x3
1 NA  1  1
2  2  2 NA
3  3  3 NA
4 NA  4  4
> test.df[is.na(test.df)] <- 1000
> test.df
    x1 x2   x3
1 1000  1    1
2    2  2 1000
3    3  3 1000
4 1000  4    4



The following search string "cran r replace data.frame NA" in Google 
(as US user) yielded some good results (5th and 7th entry), but there 
was another example that explicitly yielded this technique.  I can't 
seem to recall my exact search string.


----- Original Message ----- 
From: "David L. Van Brunt, Ph.D." <dlvanbrunt at gmail.com>
To: "R-Help List" <r-help at stat.math.ethz.ch>
Sent: Wednesday, March 14, 2007 5:22 PM
Subject: [R] replacing all NA's in a dataframe with zeros...

> I've seen how to  replace the NA's in a single column with a data 
> frame
>
> *> mydata$ncigs[is.na(mydata$ncigs)]<-0
>
> *But this is just one column... I have thousands of columns (!) that 
> I need
> to do this, and I can't figure out a way, outside of the dreaded 
> loop, do
> replace all NA's in an entire data frame (all vars) without naming 
> each var
> separately. Yikes.
>
> I'm racking my brain on this, seems like I must be staring at the 
> obvious,
> but it eludes me. Searches have come up CLOSE, but not quite what I 
> need..
>
> Any pointers?
>
> -- 
> ---------------------------------------
> David L. Van Brunt, Ph.D.
> mailto:dlvanbrunt at gmail.com
>
> "If Tyranny and Oppression come to this land, it will be in the 
> guise of
> fighting a foreign enemy."
> --James Madison
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> 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.
>

Since you can index a matrix or dataframe with
a matrix of logicals, you can use is.na()
to index all the NA locations and replace them
all with 0 in one command.
> mydata.df <- as.data.frame(matrix(sample(c(as.numeric(NA), 1), size =
30, replace = TRUE), nrow = 6))
> mydata.df
  V1 V2 V3 V4 V5
1  1 NA  1  1  1
2  1 NA NA NA  1
3 NA NA  1 NA NA
4 NA NA NA NA  1
5 NA  1 NA NA  1
6  1 NA NA  1  1
> is.na(mydata.df)
     V1    V2    V3    V4    V5
1 FALSE  TRUE FALSE FALSE FALSE
2 FALSE  TRUE  TRUE  TRUE FALSE
3  TRUE  TRUE FALSE  TRUE  TRUE
4  TRUE  TRUE  TRUE  TRUE FALSE
5  TRUE FALSE  TRUE  TRUE FALSE
6 FALSE  TRUE  TRUE FALSE FALSE
> mydata.df[is.na(mydata.df)] <- 0
> mydata.df
  V1 V2 V3 V4 V5
1  1  0  1  1  1
2  1  0  0  0  1
3  0  0  1  0  0
4  0  0  0  0  1
5  0  1  0  0  1
6  1  0  0  1  1
> 
Steven McKinney

Statistician
Molecular Oncology and Breast Cancer Program
British Columbia Cancer Research Centre

email: smckinney at bccrc.ca

tel: 604-675-8000 x7561

BCCRC
Molecular Oncology
675 West 10th Ave, Floor 4
Vancouver B.C. 
V5Z 1L3
Canada




-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch on behalf of David L. Van Brunt, Ph.D.
Sent: Wed 3/14/2007 5:22 PM
To: R-Help List
Subject: [R] replacing all NA's in a dataframe with zeros...
 
I've seen how to  replace the NA's in a single column with a data frame

*> mydata$ncigs[is.na(mydata$ncigs)]<-0

*But this is just one column... I have thousands of columns (!) that I need
to do this, and I can't figure out a way, outside of the dreaded loop, do
replace all NA's in an entire data frame (all vars) without naming each var
separately. Yikes.

I'm racking my brain on this, seems like I must be staring at the obvious,
but it eludes me. Searches have come up CLOSE, but not quite what I need..

Any pointers?

-- 
---------------------------------------
David L. Van Brunt, Ph.D.
mailto:dlvanbrunt at gmail.com

"If Tyranny and Oppression come to this land, it will be in the guise of
fighting a foreign enemy."
--James Madison

	[[alternative HTML version deleted]]

______________________________________________
R-help at stat.math.ethz.ch mailing list
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.