GPois {ProDenICA} | R Documentation |
Fit a tilted Gaussian density via a Poisson GAM
Description
This is a contrast method for ProDenICA
. It fits a tilted
Gaussian density estimate by multiplying the Gaussian density by an
exponential tilt function using a cubic smoothing spline
Usage
GPois(x, df = 6, B = 500, order = 1, widen = 1.2, density.return = FALSE, ...)
Arguments
x |
vector of real values |
df |
degrees of freedom for the smoothing-spline fit; default is 6 |
B |
number of grid points for density estimate; default is 500 |
order |
A robustness parameter to avoid responding to outliers in
|
widen |
an expansion factor to widen the range of |
density.return |
logical variable, with default |
... |
additional arguments to GAM; typically not used |
Details
See Section 14.7.4 of 'Elements of Statistical Learning (Hastie, Tibshirani and Friedman, 2009, 2nd Edition)' for details
Value
a list with components
Gs |
estimated contrast function, which is the log of the tilting
function, evaluated at the original values of |
gs |
estimated first derivative of |
gps |
estimated second derivative of |
density |
if |
Author(s)
Trevor Hastie and Rob Tibshirani
References
Hastie, T. and Tibshirani, R. (2003) Independent Component Analysis
through Product Density Estimation in Advances in Neural Information
Processing Systems 15 (Becker, S. and Obermayer, K., eds), MIT Press,
Cambridge, MA. pp 649-656
Hastie, T., Tibshirani, R. and Friedman, J. (2009) Elements of
Statistical Learning (2nd edition), Springer.
https://hastie.su.domains/ElemStatLearn/printings/ESLII_print12_toc.pdf
See Also
ProDenICA
, G1
and G0
Examples
p=2
### Can use letters a-r below for dist
dist="n"
N=1024
A0<-mixmat(p)
s<-scale(cbind(rjordan(dist,N),rjordan(dist,N)))
x <- s %*% A0
fit=ProDenICA(x,Gfunc=GPois, whiten=TRUE, density=TRUE)
par(mfrow=c(2,1))
plot(fit)