[R] Difficulty using the tryCatch() function

[phii m@iii@g oii phiiipsmith@c@]

Thanks so much for your speedy replies. Yes, removing those brackets did 
the trick. I was relying on an example in Stackoverflow at 
https://stackoverflow.com/questions/12193779/how-to-write-trycatch-in-r

Philip

On 2021-02-07 14:36, Jeff Newmiller wrote:
> Too many curly braces. warning and error need to be arguments to 
> tryCatch.
> 
> On February 7, 2021 11:30:59 AM PST, phil using philipsmith.ca wrote:
>> I need help using the tryCatch function. I have a function and I want
>> to
>> surround it with tryCatch to catch errors and thereby avoid stopping
>> execution of my program if the function fails. In my reproducible
>> example below I have used a very simply function that just adds two
>> numbers together. My function, called Adn, compiles, but when executed
>> it generates the message: "Error in tryCatch({ : condition handlers
>> must
>> be specified with a condition class". I do not understand the error
>> message.
>> 
>> # Reproducible example for using tryCatch
>> 
>> Adn <- function(x,y) {
>>   out <- tryCatch(
>>     {
>>       x+y
>>     },
>>     {
>>       warning = function(cond) {
>>         message("There was a warning.")
>>         message("Here is the original warning message:")
>>         message(cond)
>>         return(100)
>>       }
>>     },
>>     {
>>       error = function(cond) {
>>         message("There was an error.")
>>         message("Here is the original error message:")
>>         message(cond)
>>         return(200)
>>       }
>>     },
>>     finally = {
>>       message("Error handling done.")
>>     }
>>   )
>>   if (out==100 | out==200) { z <- 0 }
>>   else { z <- x+y }
>>   return(z)
>> }
>> (result <- Adn(1,sqrt(2))) # should work fine
>> (result <- Adn(1,sqrt(-2))) # should catch a warning and set z to 0
>> (result <- Adn(1,"a")) # should catch an error and set z to 0
>> 
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