Hi All,
my script tries to do the following on factors:
> ## Check for case 3: Umsatz = 0 & Kunde = 1
> for (year in 2011:2015) {
+ Umsatz <- paste0("Umsatz_", year)
+ Kunde <- paste0("Kunde01_", year)
+ Check <- paste0("Check_U_0__Kd_1_", year)
+
+ cat('Creating', Check, 'from', Umsatz, "and", Kunde, '\n')
+
+ Kunden01[[ Check ]] <- ifelse(Kunden01[[ Umsatz ]] == 0 &
+ Kunden01[[ Kunde ]] == 1,
+ 1, 0
+ )
+ Kunden01[[ Check ]] <- factor(Kunden01[[ Check ]],
+ levels=c(1, 0),
+ labels= c("Check 0", "OK")
+ )
+
+ }
Creating Check_U_0__Kd_1_2011 from Umsatz_2011 and Kunde01_2011
Creating Check_U_0__Kd_1_2012 from Umsatz_2012 and Kunde01_2012
Creating Check_U_0__Kd_1_2013 from Umsatz_2013 and Kunde01_2013
Creating Check_U_0__Kd_1_2014 from Umsatz_2014 and Kunde01_2014
Creating Check_U_0__Kd_1_2015 from Umsatz_2015 and Kunde01_2015
>
> table(Kunden01$Check_U_0__Kd_1_2011, useNA = "ifany")
Check 0 OK <NA>
1 16 13
> table(Kunden01$Check_U_0__Kd_1_2012, useNA = "ifany")
Check 0 OK <NA>
1 17 12
> table(Kunden01$Check_U_0__Kd_1_2013, useNA = "ifany")
Check 0 OK <NA>
2 17 13
> table(Kunden01$Check_U_0__Kd_1_2014, useNA = "ifany")
Check 0 OK <NA>
1 15 14
> table(Kunden01$Check_U_0__Kd_1_2015, useNA = "ifany")
Check 0 OK <NA>
2 15 13
>
> Kunden01$Check_U_0__Kd_1_all <- ifelse(Kunden01$Check_U_0__Kd_1_2011 ==
1 |
+ Kunden01$Check_U_0__Kd_1_2012 ==
1 |
+ Kunden01$Check_U_0__Kd_1_2013 ==
1 |
+ Kunden01$Check_U_0__Kd_1_2014 ==
1 |
+ Kunden01$Check_U_0__Kd_1_2015 ==
1,
+ 1, 0)
>
> table(Kunden01$Check_U_0__Kd_1_all, useNA = "ifany")
0 <NA>
7 23
(Ann.: I made the values up. But the relations equal real world data.)
I had expected to get back a factor or at least a numeric variable
containing 0, 1 and NA, instead 1 is not included.
I searched the web for information on the treatment of logical expressions
when the data contains NA. I found:
1.
https://stat.ethz.ch/R-manual/R-devel/library/base/html/NA.html
Examples
# Some logical operations do not return NA
c(TRUE, FALSE) & NA
c(TRUE, FALSE) | NA
2.
https://stat.ethz.ch/R-manual/R-devel/library/base/html/Logic.html
NA is a valid logical object. Where a component of x or y is NA, the
result will be NA if the outcome is ambiguous. In other words NA & TRUE
evaluates to NA, but NA & FALSE evaluates to FALSE. See the examples
below.
## construct truth tables :
x <- c(NA, FALSE, TRUE)
names(x) <- as.character(x)
outer(x, x, "&") ## AND table
outer(x, x, "|") ## OR table
Ann. Not very useful. How should it be read?
3.
http://www.ats.ucla.edu/stat/r/faq/missing.htm
Good explanation for NA in general and in analysis, but no information
about NA in logical expressions.
Then I made some tests with different data types and variables with NA:
-- cut --
# 2016-04-27-001_truth_table_for_logicals_and_NA.R
# Test 1
var2 <- c(TRUE, FALSE)
var3 <- c(NA, NA)
var1 <- c(1, 1)
ds <- data.frame(var1, var2, var3)
ds
ds$value_and_logical <- ifelse(ds$var1 | ds$var2, TRUE, FALSE)
ds$logical_and_na <- ifelse(ds$var2 | ds$var3, TRUE, FALSE)
ds$value_and_na <- ifelse(ds$var1 | ds$var3, TRUE, FALSE)
print(ds)
# Output
# var1 var2 var3 value_and_logical logical_and_na value_and_na
# 1 1 TRUE NA TRUE TRUE TRUE
# 2 1 FALSE NA TRUE NA TRUE
# Test 2
ds$var1 <- factor(ds$var1, levels = c(0, 1), labels = c("NOT ok", "OK"))
ds$var2 <- factor(ds$var2, levels = c(0, 1), labels = c("NOT ok", "OK"))
ds$var3 <- factor(ds$var3, levels = c(0, 1), labels = c("NOT ok", "OK"))
ds$value_and_logical <- ifelse(ds$var1 | ds$var2, TRUE, FALSE)
ds$logical_and_na <- ifelse(ds$var2 | ds$var3, TRUE, FALSE)
ds$value_and_na <- ifelse(ds$var1 | ds$var3, TRUE, FALSE)
# Output (abbrev.)
# Warning message:
# In Ops.factor(ds$var1, ds$var3) : ?|? ist nicht sinnvoll für Faktoren
print(ds)
# Output
# var1 var2 var3 value_and_logical logical_and_na value_and_na
# 1 OK <NA> <NA> NA NA NA
# 2 OK <NA> <NA> NA NA NA
-- cut --
I had expected to get the same result in Test 2 as in Test 1.
Where can I find information and documentation about NA handling in
logical expressions on different variable types?
Kind regards
Georg
______________________________________________
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.
