R help - Jul 2010 - ifelse() and missing values in test conditions

R experts,

I have been unable to get the following ifelse statement to work as desired when
applied
to my data frame.

Example:

DF$ANYEF <-
with(DF,ifelse(PSOUGHT1=='ANY'|PSOUGHT2=='ANY'|PSOUGHT3=='ANY',PEFF,0))
  
##### this statement will be replicated 16 times for 16 unique _EF variables ###

Basically, I want each ANYEF for each row to equal the corresponding row value
for column
PEFF if 'ANY' occurs at least once among columns PSOUGHT1, PSOUGHT2, and
PSOUGHT3, and I want
ANYEF to equal 0 if 'ANY' is not present within either PSOUGHT1 or
PSOUGHT2 or PSOUGHT3. My
ifelse statement will yield NAs rather than zeroes as desired whenever
'ANY' is not present
and NAs are included in at least one of the PSOUGHT variables. This data frame
is a small subset
of a larger data frame.

Thank you,

Mike


DF <-
structure(list(SITE = c("EAST.AVE", "LAMPE",
"LAMPE", "EAST.AVE",
"EAST.AVE"), MM = c(5L, 5L, 5L, 9L, 9L), DD = c(19L, 23L, 23L, 
13L, 13L), PEFF = c(11.25, 9, 8, 1.5, 8), PSOUGHT1 = c("ANY", 
"SMB", "SMB", "YP", "ANY"), PSOUGHT2 =
c("LMB", NA, NA, NA, NA
), PSOUGHT3 = c(NA, NA, NA, NA, NA), ANYEF = c(11.25, NA, NA, 
NA, 8)), .Names = c("SITE", "MM", "DD",
"PEFF", "PSOUGHT1", "PSOUGHT2",
"PSOUGHT3", "ANYEF"), class = "data.frame",
row.names = c(24L,
38L, 39L, 471L, 472L))

Hi Mike,

Probably the simplest way from what you have done would be to just set
any NA values in the column to 0:

DF$ANYEF[is.na(DF$ANYEF)] <- 0

Alternately, you can try this.  It should work, but it is far from elegant.

DF$ANYEF <- with(DF, ifelse(
 rowSums(cbind(PSOUGHT1, PSOUGHT2, PSOUGHT3) == "ANY", na.rm = TRUE)
>=1,
 PEFF, 0))

Best regards,

Josh

On Tue, Jul 20, 2010 at 9:41 AM, Hosack, Michael <mhosack at state.pa.us>
wrote:
> R experts,
>
> I have been unable to get the following ifelse statement to work as desired
when applied
> to my data frame.
>
> Example:
>
> DF$ANYEF <-
with(DF,ifelse(PSOUGHT1=='ANY'|PSOUGHT2=='ANY'|PSOUGHT3=='ANY',PEFF,0))
>
> ##### this statement will be replicated 16 times for 16 unique _EF
variables ###
>
> Basically, I want each ANYEF for each row to equal the corresponding row
value for column
> PEFF if 'ANY' occurs at least once among columns PSOUGHT1,
PSOUGHT2, and PSOUGHT3, and I want
> ANYEF to equal 0 if 'ANY' is not present within either PSOUGHT1 or
PSOUGHT2 or PSOUGHT3. My
> ifelse statement will yield NAs rather than zeroes as desired whenever
'ANY' is not present
> and NAs are included in at least one of the PSOUGHT variables. This data
frame is a small subset
> of a larger data frame.
>
> Thank you,
>
> Mike
>
>
> DF <-
> structure(list(SITE = c("EAST.AVE", "LAMPE",
"LAMPE", "EAST.AVE",
> "EAST.AVE"), MM = c(5L, 5L, 5L, 9L, 9L), DD = c(19L, 23L, 23L,
> 13L, 13L), PEFF = c(11.25, 9, 8, 1.5, 8), PSOUGHT1 = c("ANY",
> "SMB", "SMB", "YP", "ANY"),
PSOUGHT2 = c("LMB", NA, NA, NA, NA
> ), PSOUGHT3 = c(NA, NA, NA, NA, NA), ANYEF = c(11.25, NA, NA,
> NA, 8)), .Names = c("SITE", "MM", "DD",
"PEFF", "PSOUGHT1", "PSOUGHT2",
> "PSOUGHT3", "ANYEF"), class = "data.frame",
row.names = c(24L,
> 38L, 39L, 471L, 472L))
>
> ______________________________________________
> R-help at r-project.org 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.
>


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/