Re: [R] The elegant way to test if a number is a whole number

2011-09-08 Thread Jason Morgan
Hello Alex,

Have you tried the modulus operator?

 2 %% 1
[1] 0
 2.1 %% 1
[1] 0.1

~Jason

On 2011.09.08 20:27:14, Alexander Engelhardt wrote:
 Hi,
 
  x - 0.2*5
  is.integer(x)
 
 gives me FALSE because R stores it as a float number, right?
 Is there an elegant way to work around that problem? Right now
 I'm using
 
  x - 0.2*5
  round(x) == x
 
 which returns TRUE. But more strictly I should use all.equal(),
 right?
 
 I somehow just don't like the--pardon--ugliness of those pieces
 of code. Maybe there is a beautiful way to write that. If not,
 no big problem -- I just like beautiful code :-)
 
 Cheers,
   Alex
 
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Re: [R] random interaction effect in lmer

2011-02-06 Thread Jason Morgan
Hello Federico,

You should try sending this to the mixed models mailing list (link
below). Also, it would probably help to know what the data looks like. With the
information you provide, it's hard to say what the problem could be.

r-sig-mixed-mod...@r-project.org

Best,
~Jason

On 2011.02.06, Federico Bonofiglio wrote:
 Hi dears while modeling an interaction random effect in lmer i receive the
 instantaneous error message
 
  ldlM4-lmer(ldl~rt*cd4+age+rf+pharmac+factor(hcv)+
 + hivdur+(rt:cd4|id),na.action=na.omit,REML=F)
 *Warning message:
 In mer_finalize(ans) : false convergence (8)
 *
 I think the matter lies in syntax, 'cause i sistematically receive the same
 message even when changing response...
 PS: the above model runs quite well in lme and only rarely I recive :
 *
 Errore in lme.formula(fixed = ldl ~ rt + cd4 + age + rf + pharmac +
 factor(hcv) +  :
   nlminb problem, convergence error code = 1
   message = iteration limit reached without convergence (9)
 *
 ..reason for which I switch  into lmer
 
 Thank u in advance foe any hints...;)
 -- 
 *Little u can do against ignorance,it will always disarm u:
 is the 2nd principle of thermodinamics made manifest, ...entropy in
 expansion.**But setting order is the real quest 4 truth, ..and the
 mission of a (temporally) wise dude.
 *
 
   [[alternative HTML version deleted]]
 
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Re: [R] Building correlation matrix

2010-05-25 Thread Jason Morgan
On 2010.05.25 11:52:07, Anyi Zhu wrote:
 Hi,
 
 I am a novice with R, so pardon me if the question is a piece of cake
 to some of you.
 
 Say if I have a stream of data consisting of 3 columns, 1st column is
 birth date, 2nd is death date and third is weight for each individual.
 
 My ultimate goal is to be able to compute the correlation of weight
 between any combination of two death dates, grouped by birth dates.
 
 In order to do this, my plan is to be able to use a loop of some sorts
 to split the data into n vectors, each vector consists of all birth
 dates and weight for people who are dead on the same death date. Then
 figure out the standard deviation and covariance of each of the
 combination of the vectors, figure out the correlation and finally
 bind them into a matrix (or at least a 3 column table: death date1,
 death date 2, correlation).
 
 The only problem is I know how to implement this in SQL/Excel but not in R.
 
 Could someone please offer me some guidance on this? Thanks a lot!

Hello Anyi,

I suggest you take a look at the plyr package. It allows you to easily
subset a data.frame and apply any function to that data.frame.

HTH,
~Jason

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] functions sample() and S.SI()

2010-05-11 Thread Jason Morgan
On 2010.05.11 18:30:57, Lourdes Molera wrote:
 Hello,
 I need to select a sample from a small population using simple random 
 sampling without replacement. I've found two possibilities in R, the 
 function sample() and the function S.SI() in the package 
 TeachingSampling, but I don't know which one is better.
 Can someone help me?
 Thank you

Hello Lourdes,

sample() is quite capable and is what I use for bootstrapping, etc. I am
not familiar with S.SI(), but my guess is that it probably uses sample()
under the hood. Though, it does appear that it returns some additional
information that may be handy, depending on your needs.

HTH,
~Jason

 
 
 -- 
 Lourdes Molera Peris
 Métodos Cuantitativos para la Economía y la Empresa
 Facultad de Economía y Empresa
 Universidad de Murcia
 Campus de Espinardo
 30100 Murcia
 
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Re: [R] Sata and R users GLM methods translation

2010-01-22 Thread Jason Morgan
Hello Jean-Baptiste,

On 2010.01.22 16:32:53, Jean-Baptiste Combes wrote:
 Hello,
 
 I am learning R and I am fluent in Stata and I try to translate part of my
 Stata code to R to check the reliability of the data under R. I have a
 proportion variable as a dependent variable pQSfteHT . Independent variables
 are dummies for two categorical variables called dQSvacrateHTQuali3 and
 cluster_3.  I am fitting a model with the Stata command below:
 
 glm pQSfteHT dQSvacrateHTQuali3_2 dQSvacrateHTQuali3_3 dQSvacrateHTQuali3_4
 dQSvacrateHTQuali3_5 cluster_32 cluster_33 cluster_34, link(probit)
 family(binomial) robust
 
 and the same (I expect) model with R with the command below:
 
 nurse.model-glm(pQSfteHT~dQSvacrateHTQuali3_2 + dQSvacrateHTQuali3_3 +
 dQSvacrateHTQuali3_4 + dQSvacrateHTQuali3_5 + cluster_32 + cluster_33 +
 cluster_34 ,family=binomial(link = logit))
 
 I found some differences in the parameters, could it come from the robust
 option in the Stata command? It sounds strange that a variance option would
 lead to changes in parameters estimation but I am not an econometrician.

I noticed this same thing about a year ago when comparing STATA and R
results (though, I was comparing simple linear models). It seems that,
for whatever reason, STATA was reporting slight differences in the
coefficients when applying robust. In R, on the other hand, one
typically gets robust standard errors by applying, e.g., a sandwich
estimator on the variance-covariance matrix of a model previously
estimated. I am not sure what STATA is doing, and I haven't cared enough
to check, but my understanding was also that the estimated coefficients
should not have been affected by rubust (at least in the context of a
strictly linear model).

Cheers,
~Jason

 Is anyone bilingual in R and Stata and could have a look at the syntaxes
 above?
 
 Thank you in advance
 
 Thank you also to the people answering my previous enquiry.
 
 Jean-Baptiste
 

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] lattice, add text to xyplot

2010-01-08 Thread Jason Morgan
On 2010.01.08 19:44:39, Ivan Gregoretti wrote:
 Hello listers,
 
 Does anybody know how to add text to an xyplot without whipping out
 the existing curve?
 That's all.
 
 For instance,
 
 Lets say you generate a graph like this
 
 A - data.frame(x = rnorm(100), y = rnorm(100))
 xyplot(y ~ x, data = A)
 
 How would you add 'Hello world'?
 
 I tried 6.02E23 different partial solutions found on the web and
 failed. I just need one EXAMPLE that WORKS.
 
 Unfortunately,
 
 library(lattice)
 ?panel.text
 
 shows no examples.
 
 As you see, I bring you a formidable challenge.

A - data.frame(x = rnorm(100), y = rnorm(100))
xyplot(y ~ x, data = A,
   panel = function(...) {
 panel.text(0, 0, Hello world!)
 panel.xyplot(...)
   })

A whole lot of examples lattice are available here:

http://lmdvr.r-forge.r-project.org/figures/figures.html

If you plan on using lattice often, I highly recommend Deepayan Sarkar's
book.

Hope that helps,
~Jason

 
 Thank you,
 
 Ivan
 
 Ivan Gregoretti, PhD
 National Institute of Diabetes and Digestive and Kidney Diseases
 National Institutes of Health
 5 Memorial Dr, Building 5, Room 205.
 Bethesda, MD 20892. USA.

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] as.Date question

2009-12-20 Thread Jason Morgan
Hello,

On 2009.12.20 18:06:17, MAL wrote:
 All!
 
 This piece of code:
 
 zzz1 - as.POSIXct(1999-03-18, tz=CET)
 zzz2 - as.POSIXlt(1999-03-18, tz=CET)
 zzz1 == zzz2
 as.Date(zzz1)
 as.Date(zzz2)
 
 yields TRUE for zzz1==zzz2, but the two dates returned by as.Date are 
 different:
 
  as.Date(zzz1)
 [1] 1999-03-17
  as.Date(zzz2)
 [1] 1999-03-18
 
 I'm using R 2.10.0.
 
 Would be glad for any clarifications. Thanks!

I don't know why as.Date() is giving different results, but if look at
the value of the variables, they are equal:

 zzz1 - as.POSIXct(1999-03-18, tz=CET)
 zzz2 - as.POSIXlt(1999-03-18, tz=CET)
 zzz1 == zzz2
[1] TRUE
 as.Date(zzz1)
[1] 1999-03-17
 as.Date(zzz2)
[1] 1999-03-18
 zzz1
[1] 1999-03-18 CET
 zzz2
[1] 1999-03-18 CET

Maybe someone here can explain the behavior of as.Date().

Cheers,
~Jason


-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] plotting polynomial regression line

2009-12-20 Thread Jason Morgan
Hello Amit,

On 2009.12.20 19:35:09, Amit wrote:
 Dear All,
 I am trying to plot polynomial regression line to a scatterplot. I did
 following so far:
 
 x=c(1:9335)
 y=read.table(gp.txt,header=T,sep=\t)
  length(y$PCC) # y$PCC has values between 1 to 0 in decreasing order
 [1] 9335
  plot(x,y$PCC,col=red) #scatterplot between x and y$PCC
  reg=lm(y$PCC~poly(x,6)) # calculating polynomial fit with degree 6
  abline(reg,col=blue)
 Warning message:
 In abline(reg, col = blue) :
   only using the first two of 7regression coefficients
 
 After the above warning a line is drawn in the graph parallel to the
 y-axis. But I was expecting a curve line through the scatterplot.
 Am I doing something wrong? Please help!

Take a look at ?predict. Briefly, I think this will give you what you
want:

 reg - lm(y$PCC ~ poly(x,6))
 plot(x, y$PCC, col=red)
 lines(x, predict(reg), col=blue)

Cheers,
Jason


-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] Incorporating the results of White's HCCM into a linear regression:

2009-12-04 Thread Jason Morgan
On 2009.12.03 23:52:15, Yoseph Zuback wrote:
 Hi Frank,
 
 I'm trying to repair heteroscedastic variables using the hccm. A
 statistician in my department gave an incomplete solution that included:
 
 
 OLS1$coefficients/(sqrt(hccm(OLS1)))
 
 Trying to solve my problem I get different results with the method you gave
 me and what I am trying with the code above. Lost.
 

As Frank mentioned, I think you'll need to be more specific as to what
you are needing to do (e.g., what type of heteroskedasticity you are
trying to correct for). If you simply need the error corrected standard
errors produced by hccm (from the car package), you should do something
like

sqrt(diag(hccm(OLS1))),

which will produce a vector of corrected standard errors for the
covariates included in your model. You can then calculate t-values from
there. But realize that there are 5 different versions of the correction
included in hccm, which may produce slightly different results,
especially in small samples. If you need to correct for other sources of
heteroskedasticity, see Frank's rms package or sandwich.

(And, as Frank says, please include your professional affiliation in
your emails to the list, as is suggested in the posting guide.)

HTH,
~Jason

 
 2009/12/2 Frank E Harrell Jr f.harr...@vanderbilt.edu
 
  Yoseph,
 
  What do you mean by 'incorporate into'?  If you mean to update the fit
  object's variance-covariance matrix, one approach might be
 
  require(rms)
  ols1 - ols(uer92 ~ ..., x=TRUE, y=TRUE)
  ols1 - robcov(ols1)
  anova(ols1); summary(ols1); ...  # uses 'robust' variancescovariances
 
  You can substitute bootcov for robcov to use bootstrap estimates rather
  than Huber-White sandwich estimates.  Note that coefficients are unchanged.
 
  Please provide your affiliation in e-mail postings.
 
  Frank
 
 
  Yoseph Zuback wrote:
 
  Using hccm() I got a heteroscedasticity correction factor on the diagonal
  of
  the return matrix, but I don't know how to incorporate this into my linear
  model:
 
  METHOD 1:
 
   OLS1 - lm(formula=uer92~uer+low2+mlo+spec+degree+hit)
 
 
  Coefficients:
   Estimate Std. Error t value Pr(|t|)
  (Intercept) -0.0623377  0.0323461  -1.927 0.057217 .
  uer  0.2274742  0.0758720   2.998 0.003541 **
  low2 0.0276404  0.0375770   0.736 0.463973
  mlo  0.1491490  0.0940637   1.586 0.116455
  spec-0.1139978  0.0312223  -3.651 0.000445 ***
  degree   0.0014694  0.0005316   2.764 0.006970 **
  hit -0.0164365  0.0186028  -0.884 0.379376
 
   hccm(OLS1)
 
   (Intercept)   uer  low2   mlo
  spec
  (Intercept)  9.057187e-04 -1.330377e-03 -3.486945e-05  2.184561e-04
  -4.061445e-04
  uer -1.330377e-03  5.471543e-03  3.513046e-04 -4.294427e-04
  1.629196e-03
  low2-3.486945e-05  3.513046e-04  1.378587e-03  1.241245e-04
  -5.026434e-05
  mlo  2.184561e-04 -4.294427e-04  1.241245e-04  9.796132e-03
  -1.059611e-03
  spec-4.061445e-04  1.629196e-03 -5.026434e-05 -1.059611e-03
  9.777099e-04
  degree   9.638288e-07 -2.907824e-05 -1.093692e-05 -1.867397e-05
  -8.212461e-06
  hit -3.299600e-04 -2.242984e-04  1.036364e-04 -8.158489e-04
  3.994951e-05
degree   hit
  (Intercept)  9.638288e-07 -3.299600e-04
  uer -2.907824e-05 -2.242984e-04
  low2-1.093692e-05  1.036364e-04
  mlo -1.867397e-05 -8.158489e-04
  spec-8.212461e-06  3.994951e-05
  degree   3.485174e-07  4.256330e-06
  hit  4.256330e-06  4.154505e-04
 
  I have reached my limit of R knowledge, any help is appreciated.
 
 [[alternative HTML version deleted]]
 
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  PLEASE do read the posting guide
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  and provide commented, minimal, self-contained, reproducible code.
 
 
 
  --
  Frank E Harrell Jr   Professor and Chair   School of Medicine
  Department of Biostatistics   Vanderbilt University
 
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154 North Oval Mall
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Re: [R] Data Manipulation Question

2009-12-03 Thread Jason Morgan
Please refrain from posting HTML. The results can be incomprehensible:

On 2009.12.03 13:52:09, John Filben wrote:
 Can R support data manipulation programming that is available in the SAS 
 datastep??? Specifically, can R support the following:
 -?? Read multiple dataset one record at a time and compare 
 values from each; then base on if-then logic write to multiple output files
 -?? Load a lookup table and then process a different file; 
 based on if-then logic, access and lookup values in the table
 -?? Support modular ???gosub???programming
 -?? Sort files
 -?? Date math and conversions
 -?? Would it be able to support the following type of logic:
 o Start
  Read Record from File 1
  Read Record from File 2
  Match
 ?? If Key 1  Key 2 and Key 1  Key 2, Write to output file A
 ?? If Key 1 = Key 2, Write to output file B
 ?? If Key 1  Key 2 and Key 1  Key 2, Write to output file 
 C Goto Start until File 1 Done
 ??John Filben
 Cell Phone - 773.401.2822
 Email - johnfil...@yahoo.com 
   
   [[alternative HTML version deleted]]

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154 North Oval Mall
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Re: [R] R on Large Data Sets (again)

2009-11-29 Thread Jason Morgan
On 2009.11.28 21:50:09, Daniel Nordlund wrote:
   - Is a Unix-like platform a better option than win-64? Again, would
   this solve my memory limitation problems?
  
  Possibly, but Win64 should provide plenty of memory (I believe Windows 7
  Ultimate can use up to 192 GB of memory). You just have to find the
  system that can take that much... With Unix/Linux you can probably cut
  back some overhead, and the memory management is most likely better, but
  unless you need to go over 192GB of memory, you don't necessarily have
  to move to a different platform.
  
  ~Jason
 
 Windows 64-bit can certainly handle large memory spaces, but unless
 something has changed recently it my understanding Revolution
 Computing's 64-bit is the only 64-bit version of R available for
 Windows (due to the unavailability of adequate open source compilers
 for 64-bit Windows).  So 64-bit R will need to be Revolution's
 solution or a non-Windows platform.

It appears that GNU does have a project that has had some success at
compiling 64 bit Windows applications:

http://mingw-w64.sourceforge.net/

Not sure if all of the pieces are there for an R build, though.

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] R on Large Data Sets (again)

2009-11-29 Thread Jason Morgan
On 2009.11.29 14:24:40, Prof Brian Ripley wrote:
  Windows 64-bit can certainly handle large memory spaces, but unless
  something has changed recently it my understanding Revolution
  Computing's 64-bit is the only 64-bit version of R available for
  Windows (due to the unavailability of adequate open source compilers
  for 64-bit Windows).  So 64-bit R will need to be Revolution's
  solution or a non-Windows platform.
 
 Or use a commercial Windows compiler.
 
  It appears that GNU does have a project that has had some success at
  compiling 64 bit Windows applications:
 
  http://mingw-w64.sourceforge.net/
 
 Well, some interesed people have a project to port GCC and binutils: 
 as far as I am aware that is not an official GNU project.
 
  Not sure if all of the pieces are there for an R build, though.
 
 You are welcome to show us how to do it (on the R-devel list): several 
 people have spent man months attempting this (including submitting 
 many patches to that project), and the rw-FAQ did tell you do so in 
 http://cran.r-project.org/bin/windows/base/rw-FAQ.html#How-can-I-compile-R-from-source_003f

Not a chance :)

I got away from Windows 10 years ago for exactly these reasons. I was
just trying help point a poor guy in the right direction.


-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] R on Large Data Sets (again)

2009-11-28 Thread Jason Morgan
Hello Lars,

On 2009.11.28 18:53:09, Lars Bishop wrote:
 Dear R users,
 
 I?ve search the R site for help on this topic but it is hard to find a
 precise answer for my questions.
 
 Which are the best options to overcome the RAM memory limitation problems
 when using R on ?large? data sets (such as 2 or 3 million records)?

I think you'll have to provide a more precise definition of
large---are we talking 1 GB of records or 100 GB? Also, it would help
to know what you are trying to do with the data. The documentation for
the biglm and bigmemory packages may provide some help.

 - Is the free available version of R (as opposed to the one provided
 by REvolution Computing) compatible with a windows 64-bit machine?
 And if I increase the RAM memory enough on win-64, would this
 virtually solve my memory limitation problems?

I'm not familiar enough with the commercial version of R, but I do
believe it provides better support for parallelization, which may be of
some help. I don't think, however, that this version will solve your
problem.

 - Is a Unix-like platform a better option than win-64? Again, would
 this solve my memory limitation problems?

Possibly, but Win64 should provide plenty of memory (I believe Windows 7
Ultimate can use up to 192 GB of memory). You just have to find the
system that can take that much... With Unix/Linux you can probably cut
back some overhead, and the memory management is most likely better, but
unless you need to go over 192GB of memory, you don't necessarily have
to move to a different platform. 

~Jason

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] Multivariate problems . . . with 200 resposes variables and 1 explanatory variable

2009-11-25 Thread Jason Morgan
Please see the posting guide here:

http://www.r-project.org/posting-guide.html

In short, it would be helpful if you provided more information on your
data and what the goal of your analysis is. However, to get you started,
see the polr() function in the MASS package. Depending on your
goal/data, that may help.

~Jason

On 2009.11.25 16:55:13, ychu066 wrote:
 
 How should I analysis it in R  all the resposes variables are ordinal
 from 0 to 10. and the explanatory variable is a factor ...
 -- 
 View this message in context: 
 http://old.nabble.com/Multivariate-problems-.-.-.-with-200-resposes-variables-and-1-explanatory-variable-tp26522912p26522912.html
 Sent from the R help mailing list archive at Nabble.com.
 
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*The Ohio State University*
154 North Oval Mall
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Re: [R] linear mixed model question

2009-09-07 Thread Jason Morgan
Hello Wen:

On 2009.09.06 10:49:03, Wen Huang wrote:
 Hello,
 
 I wanted to fit a linear mixed model to a data that is similar in  
 terms of design to the 'Machines' data in 'nlme' package except that  
 each worker (with triplicates) only operates one machine. I created a  
 subset of observations from 'Machines' data such that it looks the  
 same as the data I wanted to fit the model with (see code below).
 
 I fitted a model in which 'Machine' was a fixed effect and 'Worker'  
 was random (intercept), which ran perfectly. Then I decided to  
 complicate the model a little bit by fitting 'Worker' within  
 'Machine', which was saying variation among workers was nested within  
 each machine. The model could be fitted by 'lme', but when I tried to  
 get
 confidence intervals by 'intervals(fm2)' it gave me an error:
 
 Error in intervals.lme(fm2) :
Cannot get confidence intervals on var-cov components: Non-positive  
 definite approximate variance-covariance
 
 I am wondering if this is because it is impossible to fit a model like  
 'fm2' or there is some other reasons?

The problem doesn't seem to be the model specification but is most likely the
result of estimating a more complicated model with very little data. Using
the complete Machines dataset with the same model specification seems to work
fine:

# - 
#

 fm3 - lme(score ~ Machine, random = ~ Machine - 1 | Worker, data = Machines)
 intervals(fm3)
Approximate 95% confidence intervals

 Fixed effects:
lower  est.upper
(Intercept) 48.972459 52.36 55.73865
MachineB 3.093747  7.97 12.83959
MachineC10.816607 13.916667 17.01673
attr(,label)
[1] Fixed effects:

 Random Effects:
  Level: Worker 
lower  est.  upper
sd(MachineA)2.1702468 4.0792807  7.6675752
sd(MachineB)4.6301082 8.6252908 16.0677975
sd(MachineC)2.3387870 4.3894795  8.2382579
cor(MachineA,MachineB)  0.1992744 0.8027499  0.9647702
cor(MachineA,MachineC) -0.1702480 0.6225047  0.9260744
cor(MachineB,MachineC)  0.1235115 0.7708309  0.9579666

 Within-group standard error:
lower  est. upper 
0.7629124 0.9615766 1.2119736 

# - 
# 

With the restricted dataset, there are only 18 observations in 6 groups. This is
probably too little data for the (restricted) maximum likelihood technique used
by lme().

Hope that helps,

~Jason


-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] run R codes every startup.

2009-08-16 Thread Jason Morgan
On 2009.08.16 15:59:15, milton ruser wrote:
 Dear all,
 
 how can I setup R(gui) to run some commands evertime R startup?
 
 cheers
 
 milton

You'll want to read: help(Startup)

HTH,
~Jason

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] lme funcion in R

2009-08-03 Thread Jason Morgan
On 2009.08.03 10:15:46, Hongwei Dong wrote:
 Hi, R users,
   I'm using the lme function in R to estimate a 2 level mixed effects
 model, in which the size of the subject groups are different. It turned out
 that It takes forever for R to converge. I also tried the same thing in SPSS
 and SPSS can give the results out within 20 minutes. Anyone can give me some
 advice on the lme function in R, especially why R does not converge? Thanks.
 
 Harry

Hello Harry,

As Chuck mentions, providing some more information on the model and
the data you are using would be helpful. Also, be sure to compare the
optimization methods used in SPSS to that used in R. You can change
the optimization method in R if the default seems to be causing
issues. See help(lmeControl) for numerous setting options.

~Jason

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] error ellipse

2009-06-21 Thread Jason Morgan
On 2009.06.20 16:04:21, Alexandru T Codilean wrote:
 
 Dear All,
 
 I have a data set with the following structure:
 
 [A], [a], [B], [b]
 
 where [A] and [B] are measurements and [a] and [b] are the associated  
 uncertainties. I produce [B]/[A] vs. [A] plots in R and would like to  
 show uncertainties  as error ellipses (rather than error bars). Would  
 this be relatively easy to do in R?
 
 I would appreciate any help on this
 Thanks a lot
 
 Tibi

The car package has an Ellipses function that draws elliptical
confidence intervals for estimated model parameters. It's not exactly
what you want, but the code may help you create your own function.

Cheers,
~Jason

-- 
Jason W. Morgan
Graduate Student
Department of Political Science
*The Ohio State University*
154 North Oval Mall
Columbus, Ohio 43210

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Re: [R] Dummy (factor) based on a pair of variables

2009-04-18 Thread Jason Morgan
On 2009.04.18 13:52:35, Serguei Kaniovski wrote:
 Bernardo: this is not quite what I am looking for,
 
 Let the data be:
 y,i,j
 1,AUT,BEL
 2,AUT,GER
 3,BEL,GER
 
 then the dummies sould look like:
 
 y,i,j,d_AUT,d_BEL,d_GER
 1,AUT,BEL,1,1,0
 2,AUT,GER,1,0,1
 3,BEL,GER,0,1,1
 
 I can generate the above dummies but can this design be imputed in a 
 reg. model directly?
 
 Serguei

Hello Serguei,

I am sure there is a better way to do this, but the following seems to
work:

# Create sample data.frame()
i  - c(AUT, AUT, BEL)
j  - c(BEL, GER, GER)
df - data.frame(i=i, j=j)

# Create dummy vectors
df$d.aut - ifelse(df$i==AUT|df$j==AUT, 1, 0)
df$d.bel - ifelse(df$i==BEL|df$j==BEL, 1, 0)
df$d.ger - ifelse(df$i==GER|df$j==GER, 1, 0)

# Print results
df

HTH,

~Jason


--
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Graduate Student, Political Science
*The Ohio State University*

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Re: [R] Dummy (factor) based on a pair of variables

2009-04-18 Thread Jason Morgan
On 2009.04.18 15:58:30, Jason Morgan wrote:
 On 2009.04.18 13:52:35, Serguei Kaniovski wrote:
  I can generate the above dummies but can this design be imputed in a 
  reg. model directly?

Oops, I apologize for not reading the whole question. Can you do the
following:

lm(y ~ I(ifelse(df$i==AUT|df$j==AUT, 1, 0)) +
   I(ifelse(df$i==BEL|df$j==BEL, 1, 0)) +
   I(ifelse(df$i==GER|df$j==GER, 1, 0)), data=df)

If you exclude the ifelse(), you will get a vector of TRUE/FALSE,
which may or may not work.

~Jason

 Hello Serguei,
 
 I am sure there is a better way to do this, but the following seems to
 work:
 
 # Create sample data.frame()
 i  - c(AUT, AUT, BEL)
 j  - c(BEL, GER, GER)
 df - data.frame(i=i, j=j)
 
 # Create dummy vectors
 df$d.aut - ifelse(df$i==AUT|df$j==AUT, 1, 0)
 df$d.bel - ifelse(df$i==BEL|df$j==BEL, 1, 0)
 df$d.ger - ifelse(df$i==GER|df$j==GER, 1, 0)
 
 # Print results
 df
 
 HTH,
 
 ~Jason
 
 

--
Jason W. Morgan
Graduate Student, Political Science
*The Ohio State University*

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Re: [R] The R Inferno

2009-01-10 Thread Jason Morgan
Excellent read, Patrick. A very useful and clear guide.

On 2009.01.09 16:14:49, Patrick Burns wrote:
 The R Inferno is now on the Burns Statistics website at
 
 http://www.burns-stat.com/pages/Tutor/R_inferno.pdf
 
 Abstract: If you are using R and you think you're in hell,
 this is a map for you.
 
 Also, I've expanded the outline concerning R on the
 Burns Statistics 'Links' page. Suggestions (off-list) for
 additional items are encouraged.
 
 
 Patrick Burns
 patr...@burns-stat.com
 +44 (0)20 8525 0696
 http://www.burns-stat.com
 (home of The R Inferno and A Guide for the Unwilling S User)
 
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~ Jason Morgan

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