try
Continue after errors

### Description

Evaluates a possible erroneous expression without exiting to the top-level prompt.

### Usage

    try(expr, silent = FALSE, outFile = getOption("try.outFile", default = stderr()))

### Arguments

expr | An expression to evaluate. It is evaluated in the frame of the caller.
silent | A logical flag. If TRUE, the error message is not printed. If FALSE (the default), the error message is printed.
outFile | The name of a file or a connection object specifying where to print the error message.

### Details

try is implemented using the tryCatch function, creating an "error" condition handler to catch any errors.
Value
returns the value of the expression if no error occurred while evaluating the expression. If an error occurred, invisibly returns an object of class "try-error" containing the error message, with an attribute "condition" containing the error condition caught.
See Also
tryCatch.
Examples

    # avoid stopping simulation because of bad data points
    set.seed(1)
    inputs <- sapply(1:10, function(i)rpois(1,1))
    f <- function(x) if(x<1) stop("x<1") else log(x)
    val <- lapply(inputs, function(x)try(f(x)))
    unlist(val[!sapply(val, is, "try-error")]) # extract ones that worked
    rm(x); rm(y)  # make sure x, y are not defined.
    try(x)
    # Error in tryCatch(expr, error = function(e) invisible(.tryErrorHandle... :
    # object "x" not found
    res <- try(x)
    # Error in tryCatch(expr, error = function(e) invisible(.tryErrorHandle... :
    # object "x" not found
    class(res) # "try-error"
    res1 <- try(y, silent = TRUE)  # no error printout
    res1   # examine error
    x <- runif(20)
    y <- rnorm(20)
    res2 <- try(lm(x~y))
    res2  # the value of lm(x~y)

Package base version 6.1.5-18
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