[R] nlsystemfit: Errors with reproducing the manual example
Federico Tamagni
f.tamagni at sssup.it
Wed Mar 28 10:57:49 CEST 2007
Hi everybody, I'm a newbye with lots of problems :). I'm trying to use
nlsystemfit, but I recieve two error messages whose origin that I don't
understand.
1) When I try to reproduce the example reported in the systemfit package
manual, that is
library( systemfit )
data( ppine )
hg.formula <- hg ~ exp( h0 + h1*log(tht) + h2*tht^2 + h3*elev + h4*cr)
dg.formula <- dg ~ exp( d0 + d1*log(dbh) + d2*hg + d3*cr + d4*ba )
labels <- list( "height.growth", "diameter.growth" )
inst <- ~ tht + dbh + elev + cr + ba
start.values <- c(h0=-0.5, h1=0.5, h2=-0.001, h3=0.0001, h4=0.08,
+ d0=-0.5, d1=0.009, d2=0.25, d3=0.005, d4=-0.02 )
model <- list( hg.formula, dg.formula )
model.ols <- nlsystemfit( "OLS", model, start.values, data=ppine,
eqnlabels=labels )
then I get the following messages:
/
The following object(s) are masked _by_ .GlobalEnv :
dg hg
The following object(s) are masked from data ( position 3 ) :
ba cr dbh dg elev hg smi tht
Error in array(x, c(length(x), 1), if (!is.null(names(x))) list(names(x), :
dim<- : invalid first argument
/
2) When I try to do something similar on my own data (called R_manuf and
containing 3 columns named va98, ts98 and gom98) with the code
library(systemfit)
dati <- read.table("R_manuf",header=T,na.strings="nan")
attach(dati)
y1 <- va98/ts98 - 1;
y2 <- gom98 - va98;
eq1.formula <- y1.98 ~ a1*ts98^(b1-1) ;
eq2.formula <- y2.98 ~ a2*ts98^b2 ;
labels <- list("eq1", "eq2" );
start.values <- c(a1=-0.5, b1=1.02, a2=-0.8, b2=0.9 );
model <- list( eq1.formula, eq2.formula);
model.ols <- nlsystemfit( "OLS", model, start.values,
eqnlabels=labels );
print(model.ols);
then I get a different error message: /
Error in eval(expr, envir, enclos) : incorrect number of subscripts on
matrix/
Thanks for your help,
Federico
--
Federico Tamagni, PhD student
LEM - Laboratory of Economics and Management
Scuola Superiore Sant'Anna, Pisa, Italy
Phone: (+39)-050-883341
Fax: (+39)-050-883344
email: f.tamagni at sssup.it
website: https://mail.sssup.it/~f.tamagni/
More information about the R-help
mailing list