warning when calculating predicted values
20,498
Solution 1
Your variable names, as stored in the x.lm
model, refer to the x
dataframe. There are no variables of the same names in a
, so it will use those 29 from x
again, which is probably not what you wanted, thus the warning. You can do the following to always use an unqualified variable named Date
in the model:
a <- seq(as.Date(tail(x, 1)$Date), by="month", length=5)
a <- data.frame(Date = a)
x.lm <- lm(Val ~ Date, data=x)
x.pre<-predict(x.lm, newdata=a)
Solution 2
Your data.frame a
has a column named a
. You created your model with columns named Val
and Date
so that is what its looking for.
when you make your data.frame a
name that column Date
and you're good to go:
a <- data.frame(Date=a)
Then it runs without the warning.
Per comment:
Edit your lm
call to be:
lm(Val ~ Date, data=x)
Author by
user1471980
Updated on July 14, 2020Comments
-
user1471980 almost 4 years
working with a data frame
x Date Val 1/1/2012 7 2/1/2012 9 3/1/2012 20 4/1/2012 24 5/1/2012 50 a <- seq(as.Date(tail(x, 1)$Date), by="month", length=5) a <- data.frame(a) x.lm <- lm(x$Val ~ x$Date) x.pre<-predict(x.lm, newdata=a)
I am getting this erro:
Warning message: 'newdata' had 5 rows but variable(s) found have 29 rows
what am I doing wrong?
here is the dput output:
dput(x) structure(list(Date = structure(c(14610, 14641, 14669, 14700, 14730, 14761, 14791, 14822, 14853, 14883, 14914, 14944, 14975, 15006, 15034, 15065, 15095, 15126, 15156, 15187, 15218, 15248, 15279, 15309, 15340, 15371, 15400, 15431, 15461), class = "Date"), Val = c(45, 51, 56, 56, 59, 60, 60, 60, 64, 65, 75, 73, 74, 80, 87, 91, 92, 96, 109, 108, 123, 129, 133, 143, 127, 127, 123, 121, 130)), .Names = c("Date", "Val"), row.names = c(NA, 29L), class = "data.frame")