try-catch in for循环用于回归

Question

我在这段代码中运行了很多回归。

vek <- read_excel("h24.xlsx")
filterfile <- read_excel("filterfile.xlsx")

x <- c(filterfile$Column)
sink("D:/test.csv")
for (temp_var in x){
  h24 <- filter(vek,KEY == temp_var)
  h24 <- na.omit(h24)
  frml <- UNITS ~ h36+ z24+ z36+ pr
  
  if (length(unique(h24$`F`)) > 1) frml <- update.formula(frml, ~ F + .)
  if (length(unique(h24$`D`)) > 1) frml <- update.formula(frml, ~ D + .)
  
  lmtest <- lm(frml, data = h24)
  
  
print(vif(lmtest))
}
sink()

print(vif(lmtest))抛出一些错误：there are aliased coefficients in the model

在出现这些错误的情况下，我想运行alias(lmtest)

即使有一些关于trycatch()的帖子，我也不能修复它。解决这个问题最简单的方法是什么？

Answer 1

R中的tryCatch可以参考Python语言中很好的错误处理。您可以尝试使用tryCatch来捕获错误，并在必要时重新运行代码。请注意，您可以检查命令是否返回了错误，甚至可以检查到底是什么错误。

throwRandomError <- function(x = 0.5) {
  if (runif(1) > x) {
    stop("Random error encountered")
  } else {
    return(x)
  }
}

set.seed(2)
ok <- tryCatch(
  throwRandomError(x = 0.5),
  error = function(e) e
)

bad <- tryCatch(
  throwRandomError(x = 0.5),
  error = function(e) e
)

str(bad)

List of 2
 $ message: chr "Random error encountered"
 $ call   : language throwRandomError(x = 0.5)
 - attr(*, "class")= chr [1:3] "simpleError" "error" "condition"

# Catch any type of class, error, simpleError or condition.
# Only one is probably enough, but left here for redundancy.
if (class(bad) %in% c("error", "simpleError", "condition")) {
  print("Rerunning lmtest")
  result <- print(alias(lmtest))
}

您可以使用类似以下内容的内容来捕获特定错误

if (bad$message == "Random error encountered") {
  print("adapting workflow")
}