[R] vlmc - In vlmc(traffic.clusters.stationary, cutoff = i) : alphabet with 1-letter strings; trying to abbreviate
Dear all (copying the package author), I have a question on the vlmc package. I am trying to model a time series, where each element can take one of 11 values (the result of some clustering). When I run the following command (synthetic data to facilitate self-contained example) I get the following warning: (alphabet with 1-letter strings; trying to abbreviate) +++ START+++ library(VLMC) a - floor(runif(1000,0,11)) vc - vlmc(a,cutoff=5) Warning message: In vlmc(a, cutoff = 5) : alphabet with 1-letter strings; trying to abbreviate vc 'vlmc' a Variable Length Markov Chain; alphabet 'abcdefghijk', |alphabet| = 11, n = 1000. Call: vlmc(dts = a, cutoff.prune = 5) - extensions (= $size ) : ord.MC context nr.leaves total 27261 1608 AIC = 5247 +++ END+++ The questions are: 1. What is it trying to do? 2. How is it abbreviating? 3. How much should I worry about it? 4. What can I do? I have looked at the documentation plus Mc3a4chler M. and Bc3bchlmann P. (2004) Variable Length Markov Chains: Methodology, Computing, and Software. _J. Computational and Graphical Statistics_ *2*, 435-455. Thanks for any feedback, Costas -- Constantinos Antoniou, Ph.D., Assistant Professor National Technical University of Athens Laboratory of Transportation Engineering School of Rural and Surveying Engineering 9 Heroon Politechniou st., 15780-Zografou, Athens, Greece T: +30 210 7722783 - F: +30 210 7722629 anton...@central.ntua.gr - http://users.ntua.gr/antoniou __ 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] vlmc - In vlmc(traffic.clusters.stationary, cutoff = i) : alphabet with 1-letter strings; trying to abbreviate
CA == Constantinos Antoniou constantinos.antoniou.rli...@gmail.com on Wed, 30 Jun 2010 12:07:16 +0300 writes: CA == Constantinos Antoniou constantinos.antoniou.rli...@gmail.com on Wed, 30 Jun 2010 12:07:16 +0300 writes: CA Dear all (copying the package author), CA I have a question on the vlmc package. I am trying to CA model a time series, where each element can take one of CA 11 values (the result of some clustering). When I run CA the following command (synthetic data to facilitate CA self-contained example) (very good) I get the following warning: (alphabet with 1-letter strings; trying to abbreviate) +++ START+++ library(VLMC) a - floor(runif(1000,0,11)) vc - vlmc(a,cutoff=5) Warning message: In vlmc(a, cutoff = 5) : alphabet with 1-letter strings; trying to abbreviate vc 'vlmc' a Variable Length Markov Chain; alphabet 'abcdefghijk', |alphabet| = 11, n = 1000. Call: vlmc(dts = a, cutoff.prune = 5) - extensions (= $size ) : ord.MC context nr.leaves total 27261 1608 AIC = 5247 +++ END+++ The questions are: 1. What is it trying to do? Your contains values 0 1 2 .. 10 it tries to match them to 1-letter strings, but '10' is 2 letters 2. How is it abbreviating? (not really important: using abbreviate() 3. How much should I worry about it? not at all. The warning is just to inform you that your input looks a bit unusual to vlmc. I do agree however, that one could argue that vlmc() should work for inputs with values 0:m or 1:n without a warning. 4. What can I do? You could use vc - vlmc(letters[1+a], cutoff=5) to get the exact same model, but without a warning. or vc - vlmc(a, cutoff=5, quiet = TRUE) or vc - vlmc(a, cutoff=5, code1char = FALSE) I have looked at the documentation plus Mc3a4chler M. and Bc3bchlmann P. (2004) Variable Length Markov Chains: Methodology, Computing, and Software. _J. Computational and Graphical Statistics_ *2*, 435-455. That's good. The examples there all have a character vector (of strings with 1 letter/character) as input. Thanks for any feedback, You're welcome! Martin Maechler, ETH Zurich -- Constantinos Antoniou, Ph.D., Assistant Professor National Technical University of Athens Laboratory of Transportation Engineering School of Rural and Surveying Engineering 9 Heroon Politechniou st., 15780-Zografou, Athens, Greece T: +30 210 7722783 - F: +30 210 7722629 anton...@central.ntua.gr - http://users.ntua.gr/antoniou Dear all (copying the package author), I have a question on the vlmc package. I am trying to model a time series, where each element can take one of 11 values (the result of some clustering). When I run the following command (synthetic data to facilitate self-contained example) I get the following warning: (alphabet with 1-letter strings; trying to abbreviate) +++ START+++ library(VLMC) a - floor(runif(1000,0,11)) vc - vlmc(a,cutoff=5) Warning message: In vlmc(a, cutoff = 5) : alphabet with 1-letter strings; trying to abbreviate vc 'vlmc' a Variable Length Markov Chain; alphabet 'abcdefghijk', |alphabet| = 11, n = 1000. Call: vlmc(dts = a, cutoff.prune = 5) - extensions (= $size ) : ord.MC context nr.leaves total 2 72 61 1608 AIC = 5247 +++ END+++ The questions are: 1. What is it trying to do? 2. How is it abbreviating? 3. How much should I worry about it? 4. What can I do? I have looked at the documentation plus Mc3a4chler M. and Bc3bchlmann P. (2004) Variable Length Markov Chains: Methodology, Computing, and Software. _J. Computational and Graphical Statistics_ *2*, 435-455. Thanks for any feedback, Costas -- Constantinos Antoniou, Ph.D., Assistant Professor National Technical University of Athens Laboratory of Transportation Engineering School of Rural and Surveying Engineering 9 Heroon Politechniou st., 15780-Zografou, Athens, Greece T: +30 210 7722783 - F: +30 210 7722629 anton...@central.ntua.gr - http://users.ntua.gr/antoniou __ 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] vlmc - In vlmc(traffic.clusters.stationary, cutoff = i) : alphabet with 1-letter strings; trying to abbreviate
Dear Martin, Thank you very much for the (reassuring and helpful) response. Best regards, Costas On Jun 30, 2010, at 3:58 PM, Martin Maechler wrote: CA == Constantinos Antoniou constantinos.antoniou.rli...@gmail.com on Wed, 30 Jun 2010 12:07:16 +0300 writes: CA == Constantinos Antoniou constantinos.antoniou.rli...@gmail.com on Wed, 30 Jun 2010 12:07:16 +0300 writes: CA Dear all (copying the package author), CA I have a question on the vlmc package. I am trying to CA model a time series, where each element can take one of CA 11 values (the result of some clustering). When I run CA the following command (synthetic data to facilitate CA self-contained example) (very good) I get the following warning: (alphabet with 1-letter strings; trying to abbreviate) +++ START+++ library(VLMC) a - floor(runif(1000,0,11)) vc - vlmc(a,cutoff=5) Warning message: In vlmc(a, cutoff = 5) : alphabet with 1-letter strings; trying to abbreviate vc 'vlmc' a Variable Length Markov Chain; alphabet 'abcdefghijk', |alphabet| = 11, n = 1000. Call: vlmc(dts = a, cutoff.prune = 5) - extensions (= $size ) : ord.MC context nr.leaves total 27261 1608 AIC = 5247 +++ END+++ The questions are: 1. What is it trying to do? Your contains values 0 1 2 .. 10 it tries to match them to 1-letter strings, but '10' is 2 letters 2. How is it abbreviating? (not really important: using abbreviate() 3. How much should I worry about it? not at all. The warning is just to inform you that your input looks a bit unusual to vlmc. I do agree however, that one could argue that vlmc() should work for inputs with values 0:m or 1:n without a warning. 4. What can I do? You could use vc - vlmc(letters[1+a], cutoff=5) to get the exact same model, but without a warning. or vc - vlmc(a, cutoff=5, quiet = TRUE) or vc - vlmc(a, cutoff=5, code1char = FALSE) I have looked at the documentation plus Mc3a4chler M. and Bc3bchlmann P. (2004) Variable Length Markov Chains: Methodology, Computing, and Software. _J. Computational and Graphical Statistics_ *2*, 435-455. That's good. The examples there all have a character vector (of strings with 1 letter/character) as input. Thanks for any feedback, You're welcome! Martin Maechler, ETH Zurich -- Constantinos Antoniou, Ph.D., Assistant Professor National Technical University of Athens Laboratory of Transportation Engineering School of Rural and Surveying Engineering 9 Heroon Politechniou st., 15780-Zografou, Athens, Greece T: +30 210 7722783 - F: +30 210 7722629 anton...@central.ntua.gr - http://users.ntua.gr/antoniou Dear all (copying the package author), I have a question on the vlmc package. I am trying to model a time series, where each element can take one of 11 values (the result of some clustering). When I run the following command (synthetic data to facilitate self-contained example) I get the following warning: (alphabet with 1-letter strings; trying to abbreviate) +++ START+++ library(VLMC) a - floor(runif(1000,0,11)) vc - vlmc(a,cutoff=5) Warning message: In vlmc(a, cutoff = 5) : alphabet with 1-letter strings; trying to abbreviate vc 'vlmc' a Variable Length Markov Chain; alphabet 'abcdefghijk', |alphabet| = 11, n = 1000. Call: vlmc(dts = a, cutoff.prune = 5) - extensions (= $size ) : ord.MC context nr.leaves total 2 72 61 1608 AIC = 5247 +++ END+++ The questions are: 1. What is it trying to do? 2. How is it abbreviating? 3. How much should I worry about it? 4. What can I do? I have looked at the documentation plus Mc3a4chler M. and Bc3bchlmann P. (2004) Variable Length Markov Chains: Methodology, Computing, and Software. _J. Computational and Graphical Statistics_ *2*, 435-455. Thanks for any feedback, Costas -- Constantinos Antoniou, Ph.D., Assistant Professor National Technical University of Athens Laboratory of Transportation Engineering School of Rural and Surveying Engineering 9 Heroon Politechniou st., 15780-Zografou, Athens, Greece T: +30 210 7722783 - F: +30 210 7722629 anton...@central.ntua.gr - http://users.ntua.gr/antoniou __ 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.
