# [R] help with if statement with two conditions

Jim Lemon drj|m|emon @end|ng |rom gm@||@com
Tue Dec 24 00:33:24 CET 2019

```Hi Kimberley,
Since you are using a loop and therefore testing one value of
v_trends_lbs at a time, the "&" in the "if" statement should be "&&".
Pinching Bert's example but using a for loop instead of ifelse:

x <- seq(-2,2,.25)
v_lbs<-rep("",length(x))
for(i in 1:length(x)) {
if(is.na(x[i])) v_lbs<-"0"
else {
if(x[i] < 0.51 && x[i] > 0) v_lbs[i]<-"<1"
else v_lbs[i] <- format(round(x[i]), big.mark=",",scientific=FALSE)
}
}
x
v_lbs

I think this gives you the "right" answer, as I have used 0.51 to
avoid the rounding problem at 0.5. I can see that the output is
feeding into something else, and an incorrect value at the end of your
calculations would be more difficult to track back. Bert's "ifelse" is
a more elegant way to do this, although not quote as easy for the
beginner to understand.

Jim

On Tue, Dec 24, 2019 at 7:33 AM Steinmann, Kimberly using CDPR
<Kimberly.Steinmann using cdpr.ca.gov> wrote:
>
> Hi - i am not super familiar with R, but need to modify my predecessor's R code so that if a variable is >0 and < 0.5, it will be replaced with <1. I have looked at a bunch of forum threads on the subject, but cannot seem to get anything to work Any help at what i might be doing wrong much appreciated. I am definitely an R newbie!
>
> current code that works:
>       v_lbs_list <- ""
>       for (j in 2:(p_num_years+1)) {
>          if (is.na(v_trends_lbs[i, j])) {
>             v_lbs <- ' 0 '
>          } else if (v_trends_lbs[i, j] < 0.5) {
>             v_lbs <- ' \$<\$1 '
>          } else {
>             v_lbs <- format(round(v_trends_lbs[i, j]), big.mark=",", scientific=FALSE)
>          }
>          v_lbs_list <- paste(v_lbs_list, ' & ', v_lbs)
>       }
>
> my attempt to add a >0 that gets an error  pointing at the & sign:
>       v_lbs_list <- ""
>       for (j in 2:(p_num_years+1)) {
>          if (is.na(v_trends_lbs[i, j])) {
>             v_lbs <- ' 0 '
>          } else if (v_trends_lbs[i, j] < 0.5) & (v_trends_lbs[i, j] > 0) {
>             v_lbs <- ' \$<\$1 '
>          } else {
>             v_lbs <- format(round(v_trends_lbs[i, j]), big.mark=",", scientific=FALSE)
>          }
>          v_lbs_list <- paste(v_lbs_list, ' & ', v_lbs)
>       }
>
> Thanks for any help!
>
>
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