Odd behavior of a function within apply
Dear Erin,
The problem is that the data frame gets coerced to a character matrix,
and the only column with "" entries is the 9th (the second one you
supplied):
as.matrix(test1.df)
X1_1_HZP1 X1_1_HBM1_mon X1_1_HBM1_yr
1 "48160" "December" "2014"
2 "48198" "June" "2018"
3 "80027" "August" "2016"
4 "48161" "" NA
5 NA "" NA
6 "48911" "August" "1985"
7 NA "April" "2019"
8 "48197" "February" "1993"
9 "48021" "" NA
10 "11355" "December" "1990"
(Here, test1.df only contains the three columns you provided.)
A solution is to use sapply:
> sapply(test1.df, count1a)
X1_1_HZP1 X1_1_HBM1_mon X1_1_HBM1_yr
2 3 3
I hope this helps,
John
On 2022-08-08 1:22 p.m., Erin Hodgess wrote:
Hello!
I have the following data.frame
dput(test1.df[1:10,8:10])
structure(list(X1_1_HZP1 = c(48160L, 48198L, 80027L, 48161L,
NA, 48911L, NA, 48197L, 48021L, 11355L), X1_1_HBM1_mon = c("December",
"June", "August", "", "", "August", "April", "February", "",
"December"), X1_1_HBM1_yr = c(2014L, 2018L, 2016L, NA, NA, 1985L,
2019L, 1993L, NA, 1990L)), row.names = c(NA, 10L), class = "data.frame")
And the following function:
dput(count1a)
function (x)
{
if (typeof(x) == "integer")
y <- sum(is.na(x))
if (typeof(x) == "character")
y <- sum(x == "")
return(y)
}
When I use the apply function with count1a, I get the following:
apply(test1.df[1:10,8:10],2,count1a)
X1_1_HZP1 X1_1_HBM1_mon X1_1_HBM1_yr
NA 3 NA
However, when I do use columns 8 and 10, I get the correct response:
apply(test1.df[1:10,c(8,10)],2,count1a)
X1_1_HZP1 X1_1_HBM1_yr
2 3
I am really baffled. If I use count1a on a single column, it works fine. Any suggestions much appreciated. Thanks, Sincerely, Erin Erin Hodgess, PhD mailto: erinm.hodgess at gmail.com [[alternative HTML version deleted]]
______________________________________________ R-help at 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.
John Fox, Professor Emeritus McMaster University Hamilton, Ontario, Canada web: https://socialsciences.mcmaster.ca/jfox/