R help - Jul 2015 - mixtools? Fitting two-normal distributions to data where one of the two normal distributions (the one corresponding to lower values of x) is a left-truncated normal distribution.

I am trying to model the mixture of two normal distributions, where x values are
in the range of zero to some positive value. I know about mixtools and would use
it save for the fact that the the y values from the normal distribution
corresponding to the lower values of x (i.e. from zero to x/n) are from what
appears to be a left-truncated normal distribution (i.e. the y values are all
from the upper half of a normal distribution). The y values from higher values
of x (i.e. from x/n to x) all appear to come from a normal distribution. Can
someone suggest how to fit two normal distributions where one of the two
distributions is left-truncated? Can this be done using mixtools?
Thank you,
John 

John David Sorkin M.D., Ph.D.
Professor of Medicine
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology and Geriatric
Medicine
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing) 


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Hi John,

I don't know how well it will handle your truncated left distribution, but I
use the function Mclust from package mclust to fit a mixture of normal
distribution and it works very well.

Denis
> Le 2015-06-30 ? 22:22, John Sorkin <jsorkin at grecc.umaryland.edu> a
?crit :
> 
> I am trying to model the mixture of two normal distributions, where x
values are in the range of zero to some positive value. I know about mixtools
and would use it save for the fact that the the y values from the normal
distribution corresponding to the lower values of x (i.e. from zero to x/n) are
from what appears to be a left-truncated normal distribution (i.e. the y values
are all from the upper half of a normal distribution). The y values from higher
values of x (i.e. from x/n to x) all appear to come from a normal distribution.
Can someone suggest how to fit two normal distributions where one of the two
distributions is left-truncated? Can this be done using mixtools?
> Thank you,
> John 
> 
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing) 
> 
> 
> Confidentiality Statement:
> This email message, including any attachments, is for ...{{dropped:12}}