What does “Error: object ” not found” mean?

by

The error means that R could not find the variable mentioned in the error message.

The easiest way to reproduce the error is to type the name of a variable that doesn’t exist. (If you’ve defined x already, use a different variable name.)

x
## Error: object 'x' not found

The more complex version of the error has the same cause: calling a function when x does not exist.

mean(x)
## Error in mean(x) : 
##   error in evaluating the argument 'x' in selecting a method for function 'mean': Error: object 'x' not found

Once the variable has been defined, the error will not occur.

x <- 1:5
x
## [1] 1 2 3 4 5     
mean(x)
## [1] 3

You can check to see if a variable exists using ls or exists.

ls()        # lists all the variables that have been defined
exists("x") # returns TRUE or FALSE, depending upon whether x has been defined.

Errors like this can occur when you are using non-standard evaluation. For example, when using subset, the error will occur if a column name is not present in the data frame to subset.

d <- data.frame(a = rnorm(5))
subset(d, b > 0)
## Error in eval(expr, envir, enclos) : object 'b' not found

The error can also occur if you use custom evaluation.

get("var", "package:stats") #returns the var function
get("var", "package:utils")
## Error in get("var", "package:utils") : object 'var' not found

In the second case, the var function cannot be found when R looks in the utils package’s environment because utils is further down the search list than stats.

In more advanced use cases, you may wish to read:

More Related Contents:

  1. Reshaping data.frame from wide to long format
  2. ggplot with 2 y axes on each side and different scales
  3. Split data frame string column into multiple columns
  4. How to import multiple .csv files at once?
  5. How to add leading zeros?
  6. Quickly reading very large tables as dataframes
  7. Combine two data frames by rows (rbind) when they have different sets of columns
  8. Convert continuous numeric values to discrete categories defined by intervals
  9. Count number of rows per group and add result to original data frame
  10. Why does summarize or mutate not work with group_by when I load `plyr` after `dplyr`?
  11. Counting unique / distinct values by group in a data frame
  12. What are the differences between “=” and “
  13. Apply several summary functions on several variables by group in one call
  14. Formatting Decimal places in R
  15. How can I trim leading and trailing white space?
  16. ggplot2 line chart gives “geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic?”
  17. How to name variables on the fly?
  18. Cleaning up factor levels (collapsing multiple levels/labels)
  19. Plot multiple columns on the same graph in R [duplicate]
  20. Concatenate a vector of strings/character
  21. Use of ~ (tilde) in R programming Language
  22. Convert data.frame column format from character to factor
  23. Conditional merge/replacement in R
  24. Convert UNIX epoch to Date object
  25. Use variable names in functions of dplyr
  26. Access variable value where the name of variable is stored in a string
  27. Remove groups with less than three unique observations
  28. List distinct values in a vector in R
  29. Dollar sign before a variable
  30. Is there anything wrong with using T & F instead of TRUE & FALSE?

Leave a Comment