Witryna2 sie 2013 · In R, if and else are not vectorized, meaning they check whether a single condition is true (i.e., if ("french"=="french") works) and cannot handle multiple logicals (i.e., if (c ("french","foreigner")=="french") doesn't work) and R gives you the warning you're receiving. Witryna23 gru 2012 · You can try the following. Notice that we replaced the first two for loops with a call to mapply and the third for loop with a call to lapply. Also, we are creating two vectors that we will combine for vectorized multiplication. # create a table of the i-k index combinations using `expand.grid` ixk <- expand.grid (i=1:51, k=1:6) # Take a look ...
r - Nested ifelse statement - Stack Overflow
Witryna13 wrz 2024 · ifelse is vectorized and its result is as long as the test argument. all (is.na (vect)) is always just length one, hence the result. a regular if/else clause is fine here. vect <- c ("NA_NA", "14_mter", "78_ONHY") if (all (is.na (vect))) { out <- vect } else { out <- vect [vect != "NA_NA"] } out #> [1] "14_mter" "78_ONHY" WitrynaVectorized, traceback-capable. Required, select algorithm from table above. Required, select vectorization strategy -- striped is a good place to start, but scan is often faster for global alignment. Required, select solution width. 'sat' will attempt 8-bit solution but if overflow is detected it will then perform the 16-bit operation. folic rich diet nhs
if statement on arrays in R - Stack Overflow
Witryna28 mar 2024 · Specifies preferred vector width for auto-vectorization. Defaults to 'none' which allows target specific decisions. -ljemalloc; EXTRA_LIBS; ... the compiler uses the old Fortran 2003 rules when interpreting assignment statements. The left-hand side is assumed to be allocated with the correct shape to hold the right-hand side. If it is not ... Witryna23 lis 2011 · First, ifelse does NOT always evaluate both expressions - only if there are both TRUE and FALSE elements in the test vector. ifelse (TRUE, 'foo', stop ('bar')) # "foo" And in my opinion: ifelse should not be used in a non-vectorized situation. It is always slower and more error prone to use ifelse over if / else: Witryna25 sty 2024 · The case_when function in the dplyr package is handy to vectorize this type of multiple if else statements. Instead of passing the individual values to the "if" statements one can pass the entire vector for a very substantial performance improvement. Also the case_when improves the readability of the script. folic acid tablets for pregnant ladies