UtilIntrinsic2RSM {RJafroc} | R Documentation |
Convert from intrinsic to physical RSM parameters
Description
Convert intrinsic RSM parameters lambda_i
and nu_i
correspond to the physical RSM parameters lambda_i'
and nu_i'
. The physical parameters are more meaningful but they
depend on mu
. The intrinsic parameters are independent of
mu
. See book for details.
Usage
UtilIntrinsic2RSM(mu, lambda_i, nu_i)
Arguments
mu |
The mean of the Gaussian distribution for the ratings of latent
LLs, i.e. continuous ratings of lesions that were found by the search
mechanism ~ N( |
lambda_i |
The intrinsic Poisson lambda_i parameter. |
nu_i |
The intrinsic Binomial nu_i parameter. |
Details
RSM is the Radiological Search Model described in the book.
See also UtilRSM2Intrinsic
.
Value
A list containing \lambda
and \nu
References
Chakraborty DP (2006) A search model and figure of merit for observer data acquired according to the free-response paradigm, Phys Med Biol 51, 3449–3462.
Chakraborty DP (2006) ROC Curves predicted by a model of visual search, Phys Med Biol 51, 3463–3482.
Chakraborty DP (2017) Observer Performance Methods for Diagnostic Imaging - Foundations, Modeling, and Applications with R-Based Examples, CRC Press, Boca Raton, FL. https://www.routledge.com/Observer-Performance-Methods-for-Diagnostic-Imaging-Foundations-Modeling/Chakraborty/p/book/9781482214840
Examples
mu <- 2;lambda_i <- 20;nu_i <- 1.1512925
lambda <- UtilIntrinsic2RSM(mu, lambda_i, nu_i)$lambda
nu <- UtilIntrinsic2RSM(mu, lambda_i, nu_i)$nu
## note that the physical values are only constrained to be positive, but the physical variable nu
## must obey 0 <= nu <= 1