remove warnings r code example

Example: suppress error r

o <- try(1 + "a")
>  Error in 1 + "a" : non-numeric argument to binary operator
o <- try(1 + "a", silent=TRUE)  # no error printed

o <- tryCatch(1 + "a")
> Error in 1 + "a" : non-numeric argument to binary operator
o <- tryCatch(1 + "a", error=function(e){})