Re: [R] Do YOU know an equation for splines (ns)?

2012-06-11 Thread Ranae
I was able to get the predicted values from the splines.  Thanks so much
for the help.

I wrote a loop with some of the code that Bill suggested.  It seems that
when using predict with nlme, it is important to be specific with what one
is using as newdata.  This does come through in Pinheiro and Bates, I just
didn't recognize it to begin with.  Bert, I did try your code, but was only
getting coefficients, so I may have neglected a step.

##The successful code:
library(nlme)
library(splines)

rootCN-read.table(spline.txt, header=3DTRUE)
rootCN$plotF-as.factor(rootCN$plot)
rcn10G-groupedData(N ~ day | plotF, data=3DrootCN)

fit10 - lme( N~ns(day, 3), data =3D rcn10G)

plot(augPred(fit10))


t- 152:305
subject-rootCN[11:22,2]
sim-NULL
for(i in 1:12){
sim- cbind(sim, predict(fit10, data.frame(day=3Dt, plotF=3Drep(subject[i],
length(t)
}
colnames(sim) - c(subject)


par(mfrow=3Dc(4,3))
for(i in 1:12){
plot(t, sim[,i], type=3Dl, main=3Dsubject[i])
}


-Ranae

--
View this message in context: 
http://r.789695.n4.nabble.com/Do-YOU-know-an-equation-for-splines-ns-tp4632440p4633037.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.


Re: [R] Do YOU know an equation for splines (ns)?

2012-06-06 Thread Ranae
I have not been able to get predict (or most functions) to run well with
grouped data in nlme.  I may not have it coded right, but this is what it
looks like:

http://r.789695.n4.nabble.com/file/n4632567/spline.txt spline.txt 

library(nlme)
library(splines)

rootCN-read.table(spline.txt, header=TRUE)
rootCN$plotF-as.factor(rootCN$plot)

rcn10G-groupedData(N ~ day | plotF, data=rcn10)

fit10 - lme( N~ns(day, 3), data = rcn10G)

plot(augPred(fit10))

num- seq(88,300, len=200)
lines(num, predict(fit10, data.frame(day=num)))

-Ranae


Does
 ?predict.ns
 not do what you want without having to explicitly manipulate the spline
basis? 

-- Bert 

On Tue, Jun 5, 2012 at 1:56 PM, Ranae [hidden email] wrote:

 Hi, 
 
 I am looking at the change in N concentration in plant roots over 4 time 
 points and I have fit a spline to the data using ns and lme: 
 
 fit10 - lme( N~ns(day, 3), data = rcn10G) 
 
 I may want to adjust the model a little bit, but for now, let's assume
 it's 
 good.  I get output for the fixed effects: 
 
 Fixed: N ~ ns(day, 3) 
 (Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3 
  1.15676524  0.14509171  0.04459627  0.09334428 
 
 and coefficients for each experimental unit in my experiment: 
 
   (Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3 
 241.050360 -0.42666159 -0.56290877 -0.10714407 
 131.104464 -0.30825350 -0.53311653 -0.05558150 
 311.147878 -0.14548512 -0.78673906 -0.07231781 
 461.177781 -0.22278380 -0.80278177 -0.02321460 
 151.144215 -0.04484519 -0.06084798  0.07633663 
 321.213007  0.00741061  0.03896933  0.15325849 
 231.274615  0.16477514  0.00872224  0.23128320 
 411.215626  0.57050767  0.11415467  0.10608867 
 431.134203  0.48070741  0.72112899  0.18108193 
 121.091422  0.39563632  1.01521528  0.22597459 
 211.100631  0.44589314  0.98526322  0.23535739 
 351.226980  0.82419937  0.39809568  0.16900841 
 
 NOW, I want to write a spline function where I can incorporate these 
 coefficients to get the predicted N concentration value for each day. 
 However, I am having trouble finding the right spline equation, since
 there 
 are many forms on the internets. 
 
 I know it won't be a simple one, but can some one direct me to the
 equation 
 that would be best to use for ns? 
 
 Thanks a lot, 
 
 Ranae 

--
View this message in context: 
http://r.789695.n4.nabble.com/Do-YOU-know-an-equation-for-splines-ns-tp4632440p4632567.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.


[R] Do YOU know an equation for splines (ns)?

2012-06-05 Thread Ranae
Hi, 

I am looking at the change in N concentration in plant roots over 4 time
points and I have fit a spline to the data using ns and lme: 

fit10 - lme( N~ns(day, 3), data = rcn10G) 

I may want to adjust the model a little bit, but for now, let's assume it's
good.  I get output for the fixed effects: 

Fixed: N ~ ns(day, 3) 
(Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3 
 1.15676524  0.14509171  0.04459627  0.09334428 
  
and coefficients for each experimental unit in my experiment: 

   (Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3 
241.050360 -0.42666159 -0.56290877 -0.10714407 
131.104464 -0.30825350 -0.53311653 -0.05558150 
311.147878 -0.14548512 -0.78673906 -0.07231781 
461.177781 -0.22278380 -0.80278177 -0.02321460 
151.144215 -0.04484519 -0.06084798  0.07633663 
321.213007  0.00741061  0.03896933  0.15325849 
231.274615  0.16477514  0.00872224  0.23128320 
411.215626  0.57050767  0.11415467  0.10608867 
431.134203  0.48070741  0.72112899  0.18108193 
121.091422  0.39563632  1.01521528  0.22597459 
211.100631  0.44589314  0.98526322  0.23535739 
351.226980  0.82419937  0.39809568  0.16900841 

NOW, I want to write a spline function where I can incorporate these
coefficients to get the predicted N concentration value for each day. 
However, I am having trouble finding the right spline equation, since there
are many forms on the internets.   

I know it won't be a simple one, but can some one direct me to the equation
that would be best to use for ns? 

Thanks a lot, 

Ranae 


--
View this message in context: 
http://r.789695.n4.nabble.com/Do-YOU-know-an-equation-for-splines-ns-tp4632440.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.


[R] splines and ns equation

2012-05-31 Thread Ranae
Hi,

I am looking at the change in N concentration in plant roots over 4 time
points and I have fit a spline to the data using ns and lme:

fit10 - lme( N~ns(day, 3), data = rcn10G)

I may want to adjust the model a little bit, but for now, let's assume it's
good.  I get output for the fixed effects:

Fixed: N ~ ns(day, 3) 
(Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3 
 1.15676524  0.14509171  0.04459627  0.09334428 
 
and coefficients for each experimental unit in my experiment:

   (Intercept) ns(day, 3)1 ns(day, 3)2 ns(day, 3)3
241.050360 -0.42666159 -0.56290877 -0.10714407
131.104464 -0.30825350 -0.53311653 -0.05558150
311.147878 -0.14548512 -0.78673906 -0.07231781
461.177781 -0.22278380 -0.80278177 -0.02321460
151.144215 -0.04484519 -0.06084798  0.07633663
321.213007  0.00741061  0.03896933  0.15325849
231.274615  0.16477514  0.00872224  0.23128320
411.215626  0.57050767  0.11415467  0.10608867
431.134203  0.48070741  0.72112899  0.18108193
121.091422  0.39563632  1.01521528  0.22597459
211.100631  0.44589314  0.98526322  0.23535739
351.226980  0.82419937  0.39809568  0.16900841

NOW, I want to write a spline function where I can incorporate these
coefficients to get the predicted N concentration value for each day. 
However, I am having trouble finding the right spline equation, since there
are many forms on the internets.  

I know it won't be a simple one, but can some one direct me to the equation
that would be best to use for ns?

Thanks a lot,

Ranae



--
View this message in context: 
http://r.789695.n4.nabble.com/splines-and-ns-equation-tp4631986.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.


[R] SSfol in nlme

2012-05-07 Thread Ranae
Hello, 

I am using SSfol in nlme to fit some data for the change of N concentration
(N) in plant tissue over time (gdd).  The model works nicely for 2 out of 3
treatments, so I would really like to use it, but it consistently has a bad
fit for my third treatment.  I am pasting the figure for the third treatment
only.  I feel that I have my fixed and random effects properly identified,
but have also tried many combinations to see if I can improve the fit.   

Are there any other ideas of what I can do to capture the highest point of N
with the model? 

http://r.789695.n4.nabble.com/file/n4615613/Predicted_N_2.png 



Here is my code for the figure followed by a link to the dataset. 

library(nlme) 
cna-read.table(aboveground C and N, dates removed, zeros added.txt,
header=TRUE) 

###Aboveground 2011, treatment PF only 
n11a-subset(cna, cna$year == 2011  cna$ground == Above  cna$trt ==
PF) 
n11a$plotF - as.factor(n11a$plot) 
n11aG-groupedData(N ~ gdd | plotF, data=n11a) 

fit.dose- nlsList(N ~ SSfol(dose, gdd, lke, lka, lCl), data = n11aG) 
plot(intervals(fit.dose), layout=c(3,1)) 

fit.nlme.11a- nlme(fit.dose, random=pdDiag(lCl ~ 1)) 

fit.nlme2.11a-update(fit.nlme.11a, random = list(lCl + lka ~ 1)) 
png(thermaltimefigs/Predicted N 1.png) 
plot(augPred(fit.nlme.11a), level = 0:1) 
dev.off() 

png(thermaltimefigs/Predicted N 2.png) 
plot(augPred(fit.nlme2.11a), level = 0:1) 
dev.off() 

data at:
http://dl.dropbox.com/u/21080842/aboveground%20C%20and%20N%2C%20dates%20removed%2C%20zeros%20added.txt

Thanks, 

Ranae 

--
View this message in context: 
http://r.789695.n4.nabble.com/SSfol-in-nlme-tp4615613.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.


[R] Fitting a first order compartment model in nlme

2012-05-01 Thread Ranae
Hello,

I am using SSfol in nlme to fit some data for the change of N concentration
(N) in plant tissue over time (gdd).  The model works nicely for 2 out of 3
treatments, so I would really like to use it, but it consistently has a bad
fit for my third treatment.  I am pasting the figure for the third treatment
only.  I feel that I have my fixed and random effects properly identified,
but have also tried many combinations to see if I can improve the fit.  

Are there any other ideas of what I can do to capture the highest point of N
with the model?

http://r.789695.n4.nabble.com/file/n4601419/Predicted_N_2.png 

Here is my code for the figure followed by a link to the dataset.

library(nlme)
cna-read.table(aboveground C and N, dates removed, zeros added.txt,
header=TRUE)

###Aboveground 2011, treatment PF only
n11a-subset(cna, cna$year == 2011  cna$ground == Above  cna$trt ==
PF)
n11a$plotF - as.factor(n11a$plot)
n11aG-groupedData(N ~ gdd | plotF, data=n11a)

fit.dose- nlsList(N ~ SSfol(dose, gdd, lke, lka, lCl), data = n11aG)
plot(intervals(fit.dose), layout=c(3,1))

fit.nlme.11a- nlme(fit.dose, random=pdDiag(lCl ~ 1))

fit.nlme2.11a-update(fit.nlme.11a, random = list(lCl + lka ~ 1))
png(thermaltimefigs/Predicted N 1.png)
plot(augPred(fit.nlme.11a), level = 0:1)
dev.off()

png(thermaltimefigs/Predicted N 2.png)
plot(augPred(fit.nlme2.11a), level = 0:1)
dev.off()

data at:
http://dl.dropbox.com/u/21080842/aboveground%20C%20and%20N%2C%20dates%20removed%2C%20zeros%20added.txt

Thanks,

Ranae








--
View this message in context: 
http://r.789695.n4.nabble.com/Fitting-a-first-order-compartment-model-in-nlme-tp4601419.html
Sent from the R help mailing list archive at Nabble.com.

__
R-help@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.