Displaying 4 results from an estimated 4 matches for "ksat".
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kat
2007 Jan 28
1
extra panel arguments to plot.nmGroupedData {nlme}
Greetings,
I have a groupedData (nmGroupedData) object created with the following syntax:
Soil <- groupedData(
ksat ~ conc | soil_id/sar/rep,
data=soil.data,
labels=list(x='Solution Concentration', y='Saturated Hydraulic Conductivity'),
units=list(x='(cmol_c)', y='(cm/s)')
)
the original data represents longitudinal observations in the form of:
'data.frame': 1197 o...
2011 Mar 15
1
Problem with nls.lm function of minpack.lm package.
...the angle between `fvec' and any column of the
> Jacobian is at most `gtol' in absolute value.
> I dont know what I can do for solve my problem
>
> Here his the code
>
> #fonction pour simulation des donn?es de conductivit? hydraulique
> f.k <- function(h, alp, n, L, ksat){
> ksat <- 0.000108
> k.mod <-expression(ksat+((((1+(alp*h)^n)^(n-(1/n))-((alp*h)^(n-1)))^2)/((1+(alp*h)^n)^((n-(1/n))*(L+2)))))
>
> eval (k)
> }
> #fonction d'aide pour le gradient analytique
> j.k <- function(h, alp, n, L, ksat){
> ksat <- 0.000108
>...
2008 Jul 15
2
meaning of tests presented in anova(ols(...)) {Design package}
Hi,
I am curious about how to interpret the table produced by
anova(ols(...)), from the Design package. I have a multiple linear
regression model, with some interaction, defined by:
ols(formula = log(ksat * 60 * 60) ~ log(sar) * pol(activity,
3) + log(conc) * pol(sand, 3), data = sm.clean, x = TRUE,
y = TRUE)
n Model L.R. d.f. R2 Sigma
1834 1203 14 0.48 1.2
Residuals:
Min 1Q Median 3Q Max
-5.033 -0.859 0.016 0.739...
2007 Jul 25
0
DF and intercept term meaning for mixed (lme) models
...of freedom in the numerator), denDF (DF in the denomenator), as well as the
Intercept term in the output.
For example:
I have a groupedData object called 'Soil', and am fitting an lme model as
follows:
## fit a simple model
# errors partitioned among replicates
fit1 <- lme(
? ?log(ksat) ~ log(conc) + ordered(sar) + soil_id ,
? ?random = ~ 1 | rep,
? ?data=Soil
)
## check significance of model terms
anova(fit1)
? ? ? ? ? ? ? numDF denDF ?F-value p-value
(Intercept) ? ? ?1 ?1253 64313.21 ?<.0001
log(conc) ? ? ? ?1 ? 597 ? 173.34 ?<.0001
ordered(sar) ? ? 2 ? 597 ? ?13.87 ?&l...