[R] missing value with sign observed

[Ben Bolker]

kate <yhsu6 <at> uiuc.edu> writes:

[snip]

> 
> When I read this txt file into R and attach this data, I found the output of y
is as the follows  
> [1] 8  5  3  +  -1 + 
> Levels: -1 + 3 5 8
> 
> Could I get rid of Levels in the output? Because I need to use the observed y
and x run regression first and then
> assign the value to the missing y later.
> 

  You probably want to use the argument na.strings="+" in your
input command (scan or read.table) -- R is interpreting the
existence of a non-numeric value in your input as evidence
that you want that variable to be a factor (a categorical,
non-numeric variable).

  Ben Bolker