[R] points

[David Winsemius]

On Jul 31, 2012, at 9:01 AM, B787s wrote:

> Dear R-Help,
>
> I am using 'rms' package to draw nomogram. I wonder how is the  
> "Points"
> determined for each predictor in the model? Is it by the coefficient
> estimate (beta) relative to the highest effect in the model or?

It would be better if you asked this question about a specific example  
because the rms package has many sorts of regression fit-objects for  
which nomogram will provide results. The linear predictor in a  
regression method will have contributions from each of the terms, so I  
would have said that the variate scales were being displayed relative  
to the mean values rather than relative to the "highest effect" ...  
what ever that term means to you.

The upper portion of a nomogram is used to calculate "Points", while  
the lower portion is used to calculate probability of event by  
transforming from the linear predictor scale to the response scale. A  
unit-increment in "Points" displayed by 'plot.nomogram' for one  
variate will be related to a unit increment of another variate by the  
ratios of their coefficients.


> Thanks
> Lin
>


David Winsemius, MD
Alameda, CA, USA