Error with Design.Function(fit)

Hi all,

I'm reposting this with a more appropriate subject.

Do I need to define limits as the error message seems to suggest? If so, how? The error message, my code, the output and the first few lines of my data are all below.

Thank you!

"Error in Getlim(at, allow.null = TRUE, need.all = TRUE) :
  variable dmodel.df does not have limits defined in fit or with datadist"

My code:
==================
library(Hmisc); library(Design); library(lattice); 

dmodel.df = read.table("./data_cub3.txt", header=TRUE, nrows=100)
f <- ols(dmodel.df$y1 ~ rcs(dmodel.df$x1,3) )

print(f)

dd <- datadist(dmodel.df$x1)
options(datadist="dd")
describe(dmodel.df)

print( Function(f) )
plot(dmodel.df$x1, dmodel.df$y1)
plot(f, add=TRUE, col="blue", pch=2)

Output:
====================
Linear Regression Model

ols(formula = dmodel.df$y1 ~ rcs(dmodel.df$x1, 3))

         n Model L.R.       d.f.         R2      Sigma
       100      501.6          2     0.9934      45128

Residuals:
     Min       1Q   Median       3Q      Max
-68644.8 -31355.6   -849.9  31823.3 154196.6

Coefficients:
           Value Std. Error      t  Pr(>|t|)
Intercept  35925    12789.6  2.809 0.0060121
dmodel.df  -1620      422.9 -3.832 0.0002260
dmodel.df' 25202      523.9 48.102 0.0000000

Residual standard error: 45130 on 97 degrees of freedom
Adjusted R-Squared: 0.9932

Error in Getlim(at, allow.null = TRUE, need.all = TRUE) :
  variable dmodel.df does not have limits defined in fit or with datadist

Sample data:
=========================
config    benchmark    x1    noise    y1
1    verify2    1    0.72    282
2    verify2    2    1.6    256