Dear nmusers,
I have a big doubt. When I used the bootstrap to evaluate my model, I
had some bugs. In my code I use IGNORE statements based on FLAGS for
some outliers. I don't know if I remove these IGNORE statements, the
bootstrap will run well. Can you give me some suggestions???????
Regards
Niurys de Castro Suárez
--
MSc Niurys de Castro Suárez
Profesor Asistente Farmacometría
Investigador Agregado
Departamento Farmacia
Instituto de Farmacia y Alimentos, Universidad de La Habana
Cuba
"Una estrella brilla en la hora de nuestro encuentro"
bootstrap
Hi Niurys,
The simplest method to ensure a good bootstrap is often to simplify the data
file by removing rows that should not be used for the modeling before
running the bootstrap. Notably, if you exclude an entire subject either
based on the ID column or another column, usually the boostrap will not work
correctly.
I believe that most if not all tools generate the bootstrap with new ID
column values (the ID is given a new sequential value based on sampling
order). If you exclude an entire subject based on another column, the you
will not have the expected number of subjects in the analysis because all
the bootstrap tools that I know of don't account for exclusions with making
the new data file.
If this doesn't help, giving more info will help. (What tool are you using
for bootstrap? What command line are you running? Can you share the model
and a snippet of the data?)
Thanks,
Bill
Quoted reply history
-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Niurys.CS
Sent: Friday, May 10, 2019 12:17 PM
To: nmusers <[email protected]>
Subject: [NMusers] bootstrap
Dear nmusers,
I have a big doubt. When I used the bootstrap to evaluate my model, I had
some bugs. In my code I use IGNORE statements based on FLAGS for some
outliers. I don't know if I remove these IGNORE statements, the bootstrap
will run well. Can you give me some suggestions???????
Regards
Niurys de Castro Suárez
--
MSc Niurys de Castro Suárez
Profesor Asistente Farmacometría
Investigador Agregado
Departamento Farmacia
Instituto de Farmacia y Alimentos, Universidad de La Habana Cuba "Una
estrella brilla en la hora de nuestro encuentro"
Dear Nick and Bill,
Thank you for your answers, and please apologize me for din´t give you
information about my model.
I share with you part of my code as well as some results. My model
corresponds to QSS with constant Rtot approximation of TMDD The
parameter estimates obtained with this model are pausible, and are
similar to prevuios study (Rodriguez L et al, 2015). The GOF and VPC
look good.
The FLAGS correspond to some outliers based on DV of some IDs
(concentration of product). So, I don´t know if excluding these
values, the boostrap will work correctly.
;----------------------------------
$DATA data_19.csv IGNORE=@
IGNORE=(FLAG.EQ.2) IGNORE=(FLAG.EQ.3)
;----------------------------------
$SUBROUTINE ADVAN13 TOL=9
;----------------------------------
$MODEL COMP=(CENTRAL) COMP=(PERIPH1) COMP(PERIPH2)
;----------------------------------
$PK
TVCL= THETA(1)
TVV1= THETA(2)
TVQ = THETA(3)
TVV2 = THETA (4)
TVKSS = THETA (5)
TVKINT = THETA (6)
IF(DOS.EQ.50) TVRMAX= 0.175
IF(DOS.GT.50)TVRMAX=THETA(7)
CL = TVCL;*EXP(ETA(1))
V1 = TVV1*EXP(ETA(1))
Q = TVQ*EXP(ETA(2))
V2 = TVV2*EXP(ETA(3))
KSS = TVKSS;*EXP(ETA(4))
KINT = TVKINT
RMAX = TVRMAX
K = CL/V1
K12 = Q/V1
K21 = Q/V2
S1 = V1
Thank you,
Niurys
Quoted reply history
2019-05-10 12:45 GMT-05:00, Bill Denney <[email protected]>:
> Hi Niurys,
>
> The simplest method to ensure a good bootstrap is often to simplify the
> data
> file by removing rows that should not be used for the modeling before
> running the bootstrap. Notably, if you exclude an entire subject either
> based on the ID column or another column, usually the boostrap will not
> work
> correctly.
>
> I believe that most if not all tools generate the bootstrap with new ID
> column values (the ID is given a new sequential value based on sampling
> order). If you exclude an entire subject based on another column, the you
> will not have the expected number of subjects in the analysis because all
> the bootstrap tools that I know of don't account for exclusions with making
> the new data file.
>
> If this doesn't help, giving more info will help. (What tool are you using
> for bootstrap? What command line are you running? Can you share the model
> and a snippet of the data?)
>
> Thanks,
>
> Bill
>
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf
> Of Niurys.CS
> Sent: Friday, May 10, 2019 12:17 PM
> To: nmusers <[email protected]>
> Subject: [NMusers] bootstrap
>
> Dear nmusers,
>
>
> I have a big doubt. When I used the bootstrap to evaluate my model, I had
> some bugs. In my code I use IGNORE statements based on FLAGS for some
> outliers. I don't know if I remove these IGNORE statements, the bootstrap
> will run well. Can you give me some suggestions???????
>
>
> Regards
>
> Niurys de Castro Suárez
>
> --
>
> MSc Niurys de Castro Suárez
> Profesor Asistente Farmacometría
> Investigador Agregado
> Departamento Farmacia
> Instituto de Farmacia y Alimentos, Universidad de La Habana Cuba "Una
> estrella brilla en la hora de nuestro encuentro"
>
--
MSc Niurys de Castro Suárez
Profesor Asistente Farmacometría
Investigador Agregado
Departamento Farmacia
Instituto de Farmacia y Alimentos, Universidad de La Habana
Cuba
"Una estrella brilla en la hora de nuestro encuentro"
Hi Niurys,
I don't see any reason why the bootstrap won't work. Its only the IDs that are
selected randomly so the FLAGs will work just the same as in the full data set.
Good luck,
Nick
Quoted reply history
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Niurys.CS
Sent: Saturday, 11 May 2019 4:33 PM
To: Bill Denney <[email protected]>
Cc: nmusers <[email protected]>
Subject: Re: [NMusers] bootstrap
Dear Nick and Bill,
Thank you for your answers, and please apologize me for din´t give you
information about my model.
I share with you part of my code as well as some results. My model corresponds
to QSS with constant Rtot approximation of TMDD The parameter estimates
obtained with this model are pausible, and are similar to prevuios study
(Rodriguez L et al, 2015). The GOF and VPC look good.
The FLAGS correspond to some outliers based on DV of some IDs (concentration of
product). So, I don´t know if excluding these values, the boostrap will work
correctly.
;----------------------------------
$DATA data_19.csv IGNORE=@
IGNORE=(FLAG.EQ.2) IGNORE=(FLAG.EQ.3)
;----------------------------------
$SUBROUTINE ADVAN13 TOL=9
;----------------------------------
$MODEL COMP=(CENTRAL) COMP=(PERIPH1) COMP(PERIPH2)
;----------------------------------
$PK
TVCL= THETA(1)
TVV1= THETA(2)
TVQ = THETA(3)
TVV2 = THETA (4)
TVKSS = THETA (5)
TVKINT = THETA (6)
IF(DOS.EQ.50) TVRMAX= 0.175
IF(DOS.GT.50)TVRMAX=THETA(7)
CL = TVCL;*EXP(ETA(1))
V1 = TVV1*EXP(ETA(1))
Q = TVQ*EXP(ETA(2))
V2 = TVV2*EXP(ETA(3))
KSS = TVKSS;*EXP(ETA(4))
KINT = TVKINT
RMAX = TVRMAX
K = CL/V1
K12 = Q/V1
K21 = Q/V2
S1 = V1
Thank you,
Niurys
2019-05-10 12:45 GMT-05:00, Bill Denney <[email protected]>:
> Hi Niurys,
>
> The simplest method to ensure a good bootstrap is often to simplify
> the data file by removing rows that should not be used for the
> modeling before running the bootstrap. Notably, if you exclude an
> entire subject either based on the ID column or another column,
> usually the boostrap will not work correctly.
>
> I believe that most if not all tools generate the bootstrap with new
> ID column values (the ID is given a new sequential value based on
> sampling order). If you exclude an entire subject based on another
> column, the you will not have the expected number of subjects in the
> analysis because all the bootstrap tools that I know of don't account
> for exclusions with making the new data file.
>
> If this doesn't help, giving more info will help. (What tool are you
> using for bootstrap? What command line are you running? Can you
> share the model and a snippet of the data?)
>
> Thanks,
>
> Bill
>
> -----Original Message-----
> From: [email protected] <[email protected]> On
> Behalf Of Niurys.CS
> Sent: Friday, May 10, 2019 12:17 PM
> To: nmusers <[email protected]>
> Subject: [NMusers] bootstrap
>
> Dear nmusers,
>
>
> I have a big doubt. When I used the bootstrap to evaluate my model, I
> had some bugs. In my code I use IGNORE statements based on FLAGS for
> some outliers. I don't know if I remove these IGNORE statements, the
> bootstrap will run well. Can you give me some suggestions???????
>
>
> Regards
>
> Niurys de Castro Suárez
>
> --
>
> MSc Niurys de Castro Suárez
> Profesor Asistente Farmacometría
> Investigador Agregado
> Departamento Farmacia
> Instituto de Farmacia y Alimentos, Universidad de La Habana Cuba "Una
> estrella brilla en la hora de nuestro encuentro"
>
--
MSc Niurys de Castro Suárez
Profesor Asistente Farmacometría
Investigador Agregado
Departamento Farmacia
Instituto de Farmacia y Alimentos, Universidad de La Habana Cuba "Una estrella
brilla en la hora de nuestro encuentro"