Creating dummy from multiple xts objects

I have multiple xts objects which are all indicators if a stock is above or below a certain median value. These list are structured the following way the size variable is S or B the value variable is H or L and the momentum variable is D or U. This is what part of my three xts objects look like

 `         NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 "B"  "B" "B"  "S"  "S"  "B"  NA  
1990-01-01 "B"  "B" "B"  "B"  "S"  "B"  NA`  

           NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 "H"  "L" "L"  "H"  "L"  "L"  NA  
1990-01-01 "H"  "H" "L"  "H"  "L"  "L"  NA

          NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 "D"  "U" "U"  "D"  "D"  "D"  NA  
1990-01-01 "D"  "U" "D"  "D"  "D"  "U"  NA

Now i want to generate a new list which takes these three lists into account so that I can create a dummy variable equal to 1 when for example a stock is in S, L and D. The result would look something like this:

           NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 NA  NA   NA   NA   1    NA   NA  
1990-01-01 NA  NA   NA   NA   1    NA   NA

I have tried the following:

SLD_dummy <- ifelse(big_small=="S" & high_low=="L" & up_down=="D",1,NA)

However, I get the following error:

Error in `[.xts`(x, i, which.i = TRUE) : subscript out of bounds

Does anybody know how I can get the desired results? Thanks in advance for your help.

Solution

You could use replace on your xts object:

library(xts)
library(magrittr)
big_small <- as.xts(read.table(text='       NESN ROG NOVN ZURN ABBN UBSG LONN 
                   1989-12-01 "B"  "B" "B"  "S"  "S"  "B"  NA  
                   1990-01-01 "B"  "B" "B"  "B"  "S"  "B"  NA'))

high_low <- as.xts(read.table(text='       NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 "H"  "L" "L"  "H"  "L"  "L"  NA  
1990-01-01 "H"  "H" "L"  "H"  "L"  "L"  NA'))

up_down <- as.xts(read.table(text='        NESN ROG NOVN ZURN ABBN UBSG LONN 
1989-12-01 "D"  "U" "U"  "D"  "D"  "D"  NA  
1990-01-01 "D"  "U" "D"  "D"  "D"  "U"  NA'))

m <- big_small=="S" & high_low=="L" & up_down=="D"
replace(m, m==T, 1) %>% replace(., m==F, NA)
#>            NESN ROG NOVN ZURN ABBN UBSG LONN
#> 1989-12-01   NA  NA   NA   NA    1   NA   NA
#> 1990-01-01   NA  NA   NA   NA    1   NA   NA

^{Created on 2021-05-22 by the reprex package (v2.0.0)}

(or do m[m==TRUE] <- 1; m[m==FALSE] <- NA)