[R] SEM : Warning : Could not compute QR decomposition of Hessian
Anne Mimet
amimet at mnhn.fr
Thu Aug 26 13:45:06 CEST 2010
Dear John,
Thank a lot for your answer. Indeed, i misunderstood the place of
indicator variables in the path diagram, i thank they were considered
as exogeneous variables. Thanks for your answer, i changed variances
of latente variables to NA, and remove indicator variables from
fixed.x argument. Unfortunately, it doesn't change the warning message.
I place the path diagram of the model here : http://yfrog.com/n7pathdiagj
Because of the diagram complexity, i used some colors for the
different paths :
- green for environnental variable
- brown for landscape variables
- orange for municipalities variables
- blue for inter-municipalitie variables
- red for departemental variable
- grey for landuse variables
- and in dark the relations between indicator and latente variables,
errors, variances and covariances.
There must be other mistakes in the model, i can't find them.
Thanks again,
Regards,
Anne
John Fox <jfox at mcmaster.ca> a écrit :
> Dear Anne,
>
> I started to diagram your model but stopped when I noticed some problems:
> (1) Some variables, such as pays_alti, are clearly endogenous, since they
> have arrows pointing to them, yet are declared as fixed exogenous variables;
> that clearly doesn't make sense. (2) You've placed conflicting constraints
> on factor loadings and the variances of latent variables, for example
> setting both the path from the factor type_paysage to the indicator
> pays_alti and the variance of type_paysage to 1; again, that doesn't make
> sense.
>
> Do you have a path diagram for the model that you're trying to fit? It would
> in particular be helpful to have a diagram of the structural part of the
> model.
>
> Regards,
> John
>
> --------------------------------
> John Fox
> Senator William McMaster
> Professor of Social Statistics
> Department of Sociology
> McMaster University
> Hamilton, Ontario, Canada
> web: socserv.mcmaster.ca/jfox
>
>
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On
>> Behalf Of Anne Mimet
>> Sent: August-25-10 10:27 AM
>> To: r-help at r-project.org
>> Subject: [R] SEM : Warning : Could not compute QR decomposition of Hessian
>>
>> Hi useRs,
>>
>> I'm trying for the first time to use a sem. The model finally runs,
>> but gives a warning saying :
>> "In sem.default(ram = ram, S = S, N = N, param.names = pars, var.names
>> = vars, : Could not compute QR decomposition of Hessian.
>> Optimization probably did not converge. "
>>
>> I found in R-help some posts on this warning, but my attemps to modify
>> the code didn't change the warning message (i tried to give an error
>> of 1 to the latente variables). I can't figure what the problem is.
>> Here is the code :
>>
>>
>> tab<-read.table("F:/Mes documents/stats/sem/donnees_corr.txt",
>> header=T, sep="",na.strings = "NA")
>>
>> tab[,46]<-as.factor(tab[,46])
>> tab[,24]<-as.factor(tab[,24])
>> tab[,40]<-as.factor(tab[,40])
>>
>> fct_cor<-hetcor(tab, ML=T)
>> cor_tab<- fct_cor$correlations
>>
>> moment_tab<-read.moments(diag=F, names=c('c1','c2', 'c3','c4','c5',
>> 'c6','c7', 'c8', 'c9', 'ind_plando', 'long_sup15', 'long_inf15',
>> 'pente', 'est', 'sud','ouest', 'nord' ,'reg_hydriq', 'prof_sol',
>> 'pierro', 'efferv', 'struct','drainage','texture', 'route1_pond',
>> 'route2_pond',
>> 'pourcactif', 'tx_chomage', 'pourcagric', 'pourc_jeunes', 'pop99',
>> 'rev_imp_foyer','eq_CONC', 'eq_sante', 'eq_edu', 'sold_nat',
>> 'sold_mig', 'tps_dom_emp','TXEMPLOI','ORIECO','dist_paris','axe1',
>> 'axe2', 'axe3', 'dist_protect','urbanisation','pays_incli','pays_alti'))
>> # after comes the moment matrix (triangular)
>>
>> ram_tab<-specify.model()
>> type_paysage->pays_alti,NA,1
>> type_paysage->pays_incli, pays2, NA
>> pedo->reg_hydriq, NA, 1
>> pedo->prof_sol, ped8, NA
>> pedo->pierro, ped9, NA
>> pedo->efferv, ped10, NA
>> pedo->struct, ped11, NA
>> pedo->drainage, ped12, NA
>> pedo->texture, ped13, NA
>> adj_99->c1, NA,1
>> adj_99->c2, adj2,NA
>> adj_99->c3, adj3,NA
>> adj_99->c4, adj4,NA
>> adj_99->c5, adj5,NA
>> adj_99->c6, adj6,NA
>> adj_99->c7, adj7,NA
>> adj_99->c8, adj8,NA
>> adj_99->c9, adj9,NA
>> etat_hexa->axe1, NA, 1
>> etat_hexa->axe2, et2, NA
>> etat_hexa->axe3, et3, NA
>> socioBV->sold_mig, BV1, NA
>> socioBV->sold_nat, BV2, NA
>> socioBV->TXEMPLOI, BV3, NA
>> socioBV->ORIECO, BV4, NA
>> socioBV->tps_dom_emp, NA, 1
>> eqBV->eq_CONC, NA, 1
>> eqBV->eq_sante, eq2, NA
>> eqBV->eq_edu, eq3, NA
>> socio_com->pourcactif , NA, 1
>> socio_com->tx_chomage, com2, NA
>> socio_com->pourcagric, com3, NA
>> socio_com->pourc_jeunes, com4, NA
>> socio_com->pop99, com5, NA
>> socio_com->rev_imp_foyer, com7, NA
>> access_hexa->route1_pond, NA, 1
>> access_hexa->route2_pond, acc2, NA
>> hydro->ind_plando, NA, 1
>> hydro->long_sup15, eau2, NA
>> hydro->long_inf15, eau3, NA
>> topog->pente, NA, 1
>> topog->est, top2, NA
>> topog->sud, top3, NA
>> topog->nord, top4, NA
>> topog->ouest, top5, NA
>> dist_protect-> urbanisation, cor1,NA
>> dist_protect-> adj_99, cor2, NA
>> dist_protect-> etat_hexa, cor3, NA
>> topog-> urbanisation, cor4, NA
>> topog-> adj_99, cor5, NA
>> topog-> etat_hexa, cor6, NA
>> topog-> access_hexa, cor7, NA
>> topog<->hydro, cor8, NA
>> topog<->pedo, cor9, NA
>> pedo-> urbanisation, cor10, NA
>> pedo-> adj_99, cor11, NA
>> pedo-> etat_hexa, cor12, NA
>> pedo<->hydro, cor1, NA
>> hydro-> urbanisation, cor13, NA
>> hydro-> adj_99, cor14, NA
>> hydro-> etat_hexa, cor15, NA
>> access_hexa-> urbanisation, cor16, NA
>> access_hexa-> etat_hexa, cor17, NA
>> socio_com-> etat_hexa, cor18, NA
>> socio_com-> adj_99, cor19, NA
>> socio_com-> urbanisation, cor20, NA
>> dist_paris-> socio_com, cor21, NA
>> dist_paris-> access_hexa, cor22, NA
>> dist_paris-> adj_99, cor23, NA
>> dist_paris-> etat_hexa, cor24, NA
>> dist_paris-> urbanisation, cor25, NA
>> dist_paris-> socioBV, cor26, NA
>> socioBV-> eqBV, cor27, NA
>> socioBV-> urbanisation, cor28, NA
>> socioBV-> adj_99, cor29, NA
>> socioBV-> etat_hexa, cor30, NA
>> eqBV-> etat_hexa, cor31, NA
>> eqBV-> adj_99, cor32, NA
>> eqBV-> urbanisation, cor33, NA
>> etat_hexa-> urbanisation, cor34, NA
>> etat_hexa<-> adj_99, cor35, NA
>> adj_99-> urbanisation, cor36, NA
>> type_paysage-> urbanisation, cor37, NA
>> type_paysage-> adj_99, cor38, NA
>> type_paysage-> etat_hexa, cor39, NA
>> dist_paris<->dist_paris, auto1, NA
>> dist_protect<->dist_protect, auto2, NA
>> c1 <-> c1, auto4, NA
>> c2 <-> c2 , auto5, NA
>> c3 <-> c3 , auto6, NA
>> c4 <-> c4 , auto7, NA
>> c5 <-> c5 , auto8, NA
>> c6 <-> c6 , auto9, NA
>> c7 <-> c7 , auto10, NA
>> c8 <-> c8 , auto11, NA
>> c9 <-> c9 , auto12, NA
>> ind_plando <-> ind_plando, auto13, NA
>> long_sup15 <-> long_sup15 , auto14, NA
>> long_inf15 <-> long_inf15 , auto15, NA
>> pente <-> pente , auto16, NA
>> est<-> est , auto17, NA
>> sud <-> sud , auto18, NA
>> ouest<-> ouest , auto19, NA
>> nord <-> nord , auto20, NA
>> reg_hydriq <-> reg_hydriq , auto21, NA
>> prof_sol<-> prof_sol , auto22, NA
>> pierro <-> pierro , auto23, NA
>> efferv <-> efferv , auto24, NA
>> struct <-> struct , auto25, NA
>> drainage <-> drainage, auto26, NA
>> texture <-> texture , auto27, NA
>> route1_pond <->route1_pond , auto30, NA
>> route2_pond <-> route2_pond , auto31, NA
>> pourcactif <-> pourcactif , auto32, NA
>> tx_chomage <-> tx_chomage, auto33, NA
>> pourcagric <-> pourcagric , auto34, NA
>> pourc_jeunes<-> pourc_jeunes , auto36, NA
>> pop99<-> pop99 , auto36, NA
>> rev_imp_foyer <-> rev_imp_foyer , auto38, NA
>> eq_CONC <-> eq_CONC, auto39, NA
>> eq_sante <->eq_sante , auto40, NA
>> eq_edu<->eq_edu , auto41, NA
>> sold_nat<-> sold_nat , auto42, NA
>> sold_mig <-> sold_mig , auto43, NA
>> tps_dom_emp <-> tps_dom_emp , auto44, NA
>> TXEMPLOI <-> TXEMPLOI , auto45, NA
>> ORIECO <-> ORIECO , auto46, NA
>> axe1 <-> axe1 , auto47, NA
>> axe2 <-> axe2 , auto48, NA
>> axe3 <-> axe3 , auto49, NA
>> pays_incli<->pays_incli, auto70, NA
>> pays_alti<->pays_alti, auto71, NA
>> urbanisation<-> urbanisation , auto50, NA
>> type_paysage <-> type_paysage , NA,1
>> adj_99 <-> adj_99 , NA ,1
>> socioBV <-> socioBV , NA,1
>> eqBV <-> eqBV , NA ,1
>> socio_com <-> socio_com , NA,1
>> access_hexa <-> access_hexa , NA,1
>> hydro <-> hydro , NA ,1
>> topog <-> topog , NA ,1
>> pedo <-> pedo , NA ,1
>> eqBV <-> eqBV , NA ,1
>> etat_hexa<->etat_hexa, NA ,1
>>
>> sem_dyn<-sem(ram_tab, moment_tab, N=1176, raw=T,
>> fixed.x=c("pays_alti","reg_hydriq", "c1","axe1", "tps_dom_emp",
>> "pourcactif",
>> "route1_pond","ind_plando","pente"), par.size="ones")
>>
>>
>> Any help would be greatly appreciate.
>>
>> Thank you,
>>
>> Anne
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
>
Anne Mimet
Chargée d'étude, CERSP, MNHN
Doctorante LADYSS
LADYSS, 2, rue valette, 75005 paris
06 62 31 44 71
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