On Dec 3, 2013, at 12:45 PM, Juan Manuel Reyes S wrote:
> Dear R-project
>
> I could not validate one logistic model because when I used the function
> lrm.fit of the package rms the program showed a error message. It said that
> the variable Clam and offset must have same length.
Giving arguments of the same length to a regression function would certainly
seem to be appropriate.
>
> ext <- lrm.fit( ,Clam, offset="X")
"X" would be a one-element character vector. Cannot tell what the
object `Clam` might be. I certainly hope you have not been using the `attach`
function. That way lies madness.
The three first arguments to `lrm.fit` are:
x:
design matrix with no column for an intercept
y:
response vector, numeric, categorical, or character
offset:
optional numeric vector containing an offset on the logit scale
>
> In this case, Clam is variable depend or variable that we want to
> predictive and X is linear predictor of the other logistic model.
Other model?
>
> We want to evaluate a logistic model in new data set.
Evaluate? Please explain in more detail what procedure you propose. The
`validate` function in pkg:rms would need a fit object that has been created
with x=TRUE and y=TRUE.
> However, we don't
> have the development data set of logistic model, only we have the equation.
> We are using the function lrm.fit because it allows to use offset.
`lrm` does allow an offset by way of its formula argument. See Arguments section
of ?lrm
>
> What do you recommend me?
>
I recommend that you give a more complete example of your data, your
"model", and your code that presents what you actually do have in
hand.
--
David.
> Thank you member of R-project
>
> Juan Manuel Reyes
>
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>
>
David Winsemius
Alameda, CA, USA