Re: [R-sig-eco] Help plotting time series from multiple years?

2011-04-24 Thread Darren Norris
Hi Raphael,
Not sure about lattice but the ggplot2 packge has some straight forward 
examples.
see bottom figure on this page http://had.co.nz/ggplot2/scale_date.html
plus http://had.co.nz/ggplot2/scale_datetime.html
Dates need to be POSIXct 
?POSIXct 
HTH
Darren

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Message: 2
Date: Sat, 23 Apr 2011 11:06:47 -0700
From: Raphael Mazor 
To: r-sig-ecology@r-project.org
Subject: [R-sig-eco] Help plotting time series from multiple years?
Message-ID: <4db31537.1020...@sccwrp.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I would like to make a lattice plot of a variable by date from multiple 
years, where each panel is a different station, and each year is 
represented by a different line color. My data look something like this:

StationDateScore
Site15/19/2009552
Site16/23/2009578
Site18/5/2009604
Site19/15/2009618
Site14/13/2010610
Site15/11/2010618
Site16/15/2010118
Site17/20/2010592
Site19/1/2010590
Site25/18/2009628
Site26/22/2009590
Site28/4/2009628
Site29/16/2009610
Site210/20/2009618
Site24/15/2010200
Site25/11/2010118
Site26/15/2010217
Site27/20/2010479
Site29/1/2010353

I feel like this should be simple enough to do with Lattice using 
xyplot, but I'm not having much luck. Any suggestions?

Thanks!

-- 
Raphael D. Mazor
Freshwater Biologist
Southern California Coastal Water Research Project
3535 Harbor Blv Suite 110
Costa Mesa, CA 92626

Tel. (714) 755-3235
Fax. (714) 755-3299



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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Manuel Spínola
Thank you for all the responses.

Is there a way to do a complete data set from an object in R?
I have a data set with more than 3000 columns.

The subsetting is ok but it could be dangerous if you are using other 
factors to do some analysis as you need to specify the levels for all 
your factors again.

Best,

Manuel

On 24/04/2011 08:30 a.m., Gustavo Carvalho wrote:
> pa2<- subset(pa, influencia=="AP")
> pa2$influencia<- factor(pa2$influencia)
> levels(pa2$influencia)
>
> On Sun, Apr 24, 2011 at 11:24 AM, Manuel Spínola  
> wrote:
>> Thank you very much for your response, Christian, Roman, and Sarah.
>>
>> Sarah,
>>
>> I am trying your suggestion but I cannot see the levels:
>>
>>   >  pa2 = factor(subset(pa, influencia=="AP")$influencia)
>>   >  levels(pa2$influencia)
>> Error in pa2$influencia : $ operator is invalid for atomic vectors
>>
>> Best,
>>
>> Manuel
>>
>>
>>
>> On 24/04/2011 07:51 a.m., Sarah Goslee wrote:
>>> By default, read.csv() turns character variables into factors, using all the
>>> unique values as the levels.
>>>
>>> subset() retains those levels by default, as they are a vital element of the
>>> data. If you are studying some attribute of men and women, say height,
>>> even if you are only looking at the heights for women it's important to 
>>> remember
>>> that men still exist.
>>>
>>> If you don't want influencia to be a factor, you can change that in the 
>>> import
>>> stringsAsFactors=FALSE.
>>>
>>> If you do want influencia to be a factor, but want the unused levels to be
>>> removed, you can use factor() to do that.
>>>
 testdata<- data.frame(group=c("A", "B", "C", "A", "B", "C"), value=1:6)
 testdata
>>> group value
>>> 1 A 1
>>> 2 B 2
>>> 3 C 3
>>> 4 A 4
>>> 5 B 5
>>> 6 C 6
 str(testdata)
>>> 'data.frame': 6 obs. of  2 variables:
>>>$ group: Factor w/ 3 levels "A","B","C": 1 2 3 1 2 3
>>>$ value: int  1 2 3 4 5 6
 subset(testdata, group=="A")
>>> group value
>>> 1 A 1
>>> 4 A 4
 subset(testdata, group=="A")$group
>>> [1] A A
>>> Levels: A B C
 ?subset
 factor(subset(testdata, group=="A")$group)
>>> [1] A A
>>> Levels: A
>>>
>>> Sarah
>>>
>>> On Sun, Apr 24, 2011 at 9:04 AM, Manuel Spínola
>>> wrote:
 Dear list members,

 I have a question regarding too subsetting a data set in R.

 I created an object for my data:

>pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)

>levels(pa$influencia)
 [1] "AID" "AII" "AP"

 The object has 3 levels for influencia (AP, AID, AII)

 Now I subset only observations with influencia = "AID"

>pa2 = subset(pa, influencia=="AID")

 but if I ask for the levels of influencia still show me the 3 levels,
 AP, AID, AII.

>levels(pa2$influencia)
 [1] "AID" "AII" "AP"

 Why is that?

 I was thinking that I was creating a new data frame with only AID as a
 level for influencia.

 How can I make a complete new object with only the observations for
 "AID" and that the only level for influencia is indeed "AID"?

 Best,

 Manuel


>>
>> --
>> *Manuel Spínola, Ph.D.*
>> Instituto Internacional en Conservación y Manejo de Vida Silvestre
>> Universidad Nacional
>> Apartado 1350-3000
>> Heredia
>> COSTA RICA
>> mspin...@una.ac.cr
>> mspinol...@gmail.com
>> Teléfono: (506) 2277-3598
>> Fax: (506) 2237-7036
>> Personal website: Lobito de río
>> 
>> Institutional website: ICOMVIS
>>
>> [[alternative HTML version deleted]]
>>
>>
>> ___
>> R-sig-ecology mailing list
>> R-sig-ecology@r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
>>
>>


-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspin...@una.ac.cr
mspinol...@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río 

Institutional website: ICOMVIS 

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Manuel Spínola
Thank you very much Gustavo.

That works.

Manuel

On 24/04/2011 08:30 a.m., Gustavo Carvalho wrote:
> pa2<- subset(pa, influencia=="AP")
> pa2$influencia<- factor(pa2$influencia)
> levels(pa2$influencia)
>
> On Sun, Apr 24, 2011 at 11:24 AM, Manuel Spínola  
> wrote:
>> Thank you very much for your response, Christian, Roman, and Sarah.
>>
>> Sarah,
>>
>> I am trying your suggestion but I cannot see the levels:
>>
>>   >  pa2 = factor(subset(pa, influencia=="AP")$influencia)
>>   >  levels(pa2$influencia)
>> Error in pa2$influencia : $ operator is invalid for atomic vectors
>>
>> Best,
>>
>> Manuel
>>
>>
>>
>> On 24/04/2011 07:51 a.m., Sarah Goslee wrote:
>>> By default, read.csv() turns character variables into factors, using all the
>>> unique values as the levels.
>>>
>>> subset() retains those levels by default, as they are a vital element of the
>>> data. If you are studying some attribute of men and women, say height,
>>> even if you are only looking at the heights for women it's important to 
>>> remember
>>> that men still exist.
>>>
>>> If you don't want influencia to be a factor, you can change that in the 
>>> import
>>> stringsAsFactors=FALSE.
>>>
>>> If you do want influencia to be a factor, but want the unused levels to be
>>> removed, you can use factor() to do that.
>>>
 testdata<- data.frame(group=c("A", "B", "C", "A", "B", "C"), value=1:6)
 testdata
>>> group value
>>> 1 A 1
>>> 2 B 2
>>> 3 C 3
>>> 4 A 4
>>> 5 B 5
>>> 6 C 6
 str(testdata)
>>> 'data.frame': 6 obs. of  2 variables:
>>>$ group: Factor w/ 3 levels "A","B","C": 1 2 3 1 2 3
>>>$ value: int  1 2 3 4 5 6
 subset(testdata, group=="A")
>>> group value
>>> 1 A 1
>>> 4 A 4
 subset(testdata, group=="A")$group
>>> [1] A A
>>> Levels: A B C
 ?subset
 factor(subset(testdata, group=="A")$group)
>>> [1] A A
>>> Levels: A
>>>
>>> Sarah
>>>
>>> On Sun, Apr 24, 2011 at 9:04 AM, Manuel Spínola
>>> wrote:
 Dear list members,

 I have a question regarding too subsetting a data set in R.

 I created an object for my data:

>pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)

>levels(pa$influencia)
 [1] "AID" "AII" "AP"

 The object has 3 levels for influencia (AP, AID, AII)

 Now I subset only observations with influencia = "AID"

>pa2 = subset(pa, influencia=="AID")

 but if I ask for the levels of influencia still show me the 3 levels,
 AP, AID, AII.

>levels(pa2$influencia)
 [1] "AID" "AII" "AP"

 Why is that?

 I was thinking that I was creating a new data frame with only AID as a
 level for influencia.

 How can I make a complete new object with only the observations for
 "AID" and that the only level for influencia is indeed "AID"?

 Best,

 Manuel


>>
>> --
>> *Manuel Spínola, Ph.D.*
>> Instituto Internacional en Conservación y Manejo de Vida Silvestre
>> Universidad Nacional
>> Apartado 1350-3000
>> Heredia
>> COSTA RICA
>> mspin...@una.ac.cr
>> mspinol...@gmail.com
>> Teléfono: (506) 2277-3598
>> Fax: (506) 2237-7036
>> Personal website: Lobito de río
>> 
>> Institutional website: ICOMVIS
>>
>> [[alternative HTML version deleted]]
>>
>>
>> ___
>> R-sig-ecology mailing list
>> R-sig-ecology@r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
>>
>>


-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspin...@una.ac.cr
mspinol...@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río 

Institutional website: ICOMVIS 

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Manuel Spínola
Thank you Christian.

Following your suggestion I got the following result,

 > pa2 = subset(pa, influencia=="AP")
 > pa2$influencia<-as.factor(pa2$influencia)
 > levels(pa$influencia)
[1] "AID" "AII" "AP"


On 24/04/2011 07:42 a.m., Christian Parker wrote:
> You are creating a new object, but the columns that are stored as factors are 
> not being 'refactored' so you are retaining the original list of levels. To 
> fix this you can use the factor function after you subset
>
> pa2 = subset(pa, influencia=="AID")
> pa2$influencia<-as.factor(pa2$influencia)
>
>
>
> On Apr 24, 2011, at 6:04 AM, Manuel Spínola  wrote:
>
>> Dear list members,
>>
>> I have a question regarding too subsetting a data set in R.
>>
>> I created an object for my data:
>>
>>> pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
>>> levels(pa$influencia)
>> [1] "AID" "AII" "AP"
>>
>> The object has 3 levels for influencia (AP, AID, AII)
>>
>> Now I subset only observations with influencia = "AID"
>>
>>> pa2 = subset(pa, influencia=="AID")
>> but if I ask for the levels of influencia still show me the 3 levels,
>> AP, AID, AII.
>>
>>> levels(pa2$influencia)
>> [1] "AID" "AII" "AP"
>>
>> Why is that?
>>
>> I was thinking that I was creating a new data frame with only AID as a
>> level for influencia.
>>
>> How can I make a complete new object with only the observations for
>> "AID" and that the only level for influencia is indeed "AID"?
>>
>> Best,
>>
>> Manuel
>>
>>
>>
>>
>> -- 
>> *Manuel Spínola, Ph.D.*
>> Instituto Internacional en Conservación y Manejo de Vida Silvestre
>> Universidad Nacional
>> Apartado 1350-3000
>> Heredia
>> COSTA RICA
>> mspin...@una.ac.cr
>> mspinol...@gmail.com
>> Teléfono: (506) 2277-3598
>> Fax: (506) 2237-7036
>> Personal website: Lobito de río
>> 
>> Institutional website: ICOMVIS
>>
>> [[alternative HTML version deleted]]
>>
>> ___
>> R-sig-ecology mailing list
>> R-sig-ecology@r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology


-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspin...@una.ac.cr
mspinol...@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río 

Institutional website: ICOMVIS 

[[alternative HTML version deleted]]

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Gustavo Carvalho
pa2 <- subset(pa, influencia=="AP")
pa2$influencia <- factor(pa2$influencia)
levels(pa2$influencia)

On Sun, Apr 24, 2011 at 11:24 AM, Manuel Spínola  wrote:
> Thank you very much for your response, Christian, Roman, and Sarah.
>
> Sarah,
>
> I am trying your suggestion but I cannot see the levels:
>
>  > pa2 = factor(subset(pa, influencia=="AP")$influencia)
>  > levels(pa2$influencia)
> Error in pa2$influencia : $ operator is invalid for atomic vectors
>
> Best,
>
> Manuel
>
>
>
> On 24/04/2011 07:51 a.m., Sarah Goslee wrote:
>> By default, read.csv() turns character variables into factors, using all the
>> unique values as the levels.
>>
>> subset() retains those levels by default, as they are a vital element of the
>> data. If you are studying some attribute of men and women, say height,
>> even if you are only looking at the heights for women it's important to 
>> remember
>> that men still exist.
>>
>> If you don't want influencia to be a factor, you can change that in the 
>> import
>> stringsAsFactors=FALSE.
>>
>> If you do want influencia to be a factor, but want the unused levels to be
>> removed, you can use factor() to do that.
>>
>>> testdata<- data.frame(group=c("A", "B", "C", "A", "B", "C"), value=1:6)
>>> testdata
>>    group value
>> 1     A     1
>> 2     B     2
>> 3     C     3
>> 4     A     4
>> 5     B     5
>> 6     C     6
>>> str(testdata)
>> 'data.frame': 6 obs. of  2 variables:
>>   $ group: Factor w/ 3 levels "A","B","C": 1 2 3 1 2 3
>>   $ value: int  1 2 3 4 5 6
>>> subset(testdata, group=="A")
>>    group value
>> 1     A     1
>> 4     A     4
>>> subset(testdata, group=="A")$group
>> [1] A A
>> Levels: A B C
>>> ?subset
>>> factor(subset(testdata, group=="A")$group)
>> [1] A A
>> Levels: A
>>
>> Sarah
>>
>> On Sun, Apr 24, 2011 at 9:04 AM, Manuel Spínola  wrote:
>>> Dear list members,
>>>
>>> I have a question regarding too subsetting a data set in R.
>>>
>>> I created an object for my data:
>>>
>>>   >pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
>>>
>>>   >  levels(pa$influencia)
>>> [1] "AID" "AII" "AP"
>>>
>>> The object has 3 levels for influencia (AP, AID, AII)
>>>
>>> Now I subset only observations with influencia = "AID"
>>>
>>>   >pa2 = subset(pa, influencia=="AID")
>>>
>>> but if I ask for the levels of influencia still show me the 3 levels,
>>> AP, AID, AII.
>>>
>>>   >  levels(pa2$influencia)
>>> [1] "AID" "AII" "AP"
>>>
>>> Why is that?
>>>
>>> I was thinking that I was creating a new data frame with only AID as a
>>> level for influencia.
>>>
>>> How can I make a complete new object with only the observations for
>>> "AID" and that the only level for influencia is indeed "AID"?
>>>
>>> Best,
>>>
>>> Manuel
>>>
>>>
>
>
> --
> *Manuel Spínola, Ph.D.*
> Instituto Internacional en Conservación y Manejo de Vida Silvestre
> Universidad Nacional
> Apartado 1350-3000
> Heredia
> COSTA RICA
> mspin...@una.ac.cr
> mspinol...@gmail.com
> Teléfono: (506) 2277-3598
> Fax: (506) 2237-7036
> Personal website: Lobito de río
> 
> Institutional website: ICOMVIS 
>
>        [[alternative HTML version deleted]]
>
>
> ___
> R-sig-ecology mailing list
> R-sig-ecology@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
>
>

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Manuel Spínola
Thank you very much for your response, Christian, Roman, and Sarah.

Sarah,

I am trying your suggestion but I cannot see the levels:

 > pa2 = factor(subset(pa, influencia=="AP")$influencia)
 > levels(pa2$influencia)
Error in pa2$influencia : $ operator is invalid for atomic vectors

Best,

Manuel



On 24/04/2011 07:51 a.m., Sarah Goslee wrote:
> By default, read.csv() turns character variables into factors, using all the
> unique values as the levels.
>
> subset() retains those levels by default, as they are a vital element of the
> data. If you are studying some attribute of men and women, say height,
> even if you are only looking at the heights for women it's important to 
> remember
> that men still exist.
>
> If you don't want influencia to be a factor, you can change that in the import
> stringsAsFactors=FALSE.
>
> If you do want influencia to be a factor, but want the unused levels to be
> removed, you can use factor() to do that.
>
>> testdata<- data.frame(group=c("A", "B", "C", "A", "B", "C"), value=1:6)
>> testdata
>group value
> 1 A 1
> 2 B 2
> 3 C 3
> 4 A 4
> 5 B 5
> 6 C 6
>> str(testdata)
> 'data.frame': 6 obs. of  2 variables:
>   $ group: Factor w/ 3 levels "A","B","C": 1 2 3 1 2 3
>   $ value: int  1 2 3 4 5 6
>> subset(testdata, group=="A")
>group value
> 1 A 1
> 4 A 4
>> subset(testdata, group=="A")$group
> [1] A A
> Levels: A B C
>> ?subset
>> factor(subset(testdata, group=="A")$group)
> [1] A A
> Levels: A
>
> Sarah
>
> On Sun, Apr 24, 2011 at 9:04 AM, Manuel Spínola  wrote:
>> Dear list members,
>>
>> I have a question regarding too subsetting a data set in R.
>>
>> I created an object for my data:
>>
>>   >pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
>>
>>   >  levels(pa$influencia)
>> [1] "AID" "AII" "AP"
>>
>> The object has 3 levels for influencia (AP, AID, AII)
>>
>> Now I subset only observations with influencia = "AID"
>>
>>   >pa2 = subset(pa, influencia=="AID")
>>
>> but if I ask for the levels of influencia still show me the 3 levels,
>> AP, AID, AII.
>>
>>   >  levels(pa2$influencia)
>> [1] "AID" "AII" "AP"
>>
>> Why is that?
>>
>> I was thinking that I was creating a new data frame with only AID as a
>> level for influencia.
>>
>> How can I make a complete new object with only the observations for
>> "AID" and that the only level for influencia is indeed "AID"?
>>
>> Best,
>>
>> Manuel
>>
>>


-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspin...@una.ac.cr
mspinol...@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río 

Institutional website: ICOMVIS 

[[alternative HTML version deleted]]

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Sarah Goslee
By default, read.csv() turns character variables into factors, using all the
unique values as the levels.

subset() retains those levels by default, as they are a vital element of the
data. If you are studying some attribute of men and women, say height,
even if you are only looking at the heights for women it's important to remember
that men still exist.

If you don't want influencia to be a factor, you can change that in the import
stringsAsFactors=FALSE.

If you do want influencia to be a factor, but want the unused levels to be
removed, you can use factor() to do that.

> testdata <- data.frame(group=c("A", "B", "C", "A", "B", "C"), value=1:6)
> testdata
  group value
1 A 1
2 B 2
3 C 3
4 A 4
5 B 5
6 C 6
> str(testdata)
'data.frame':   6 obs. of  2 variables:
 $ group: Factor w/ 3 levels "A","B","C": 1 2 3 1 2 3
 $ value: int  1 2 3 4 5 6
> subset(testdata, group=="A")
  group value
1 A 1
4 A 4
> subset(testdata, group=="A")$group
[1] A A
Levels: A B C
> ?subset
> factor(subset(testdata, group=="A")$group)
[1] A A
Levels: A

Sarah

On Sun, Apr 24, 2011 at 9:04 AM, Manuel Spínola  wrote:
> Dear list members,
>
> I have a question regarding too subsetting a data set in R.
>
> I created an object for my data:
>
>  >pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
>
>  > levels(pa$influencia)
> [1] "AID" "AII" "AP"
>
> The object has 3 levels for influencia (AP, AID, AII)
>
> Now I subset only observations with influencia = "AID"
>
>  >pa2 = subset(pa, influencia=="AID")
>
> but if I ask for the levels of influencia still show me the 3 levels,
> AP, AID, AII.
>
>  > levels(pa2$influencia)
> [1] "AID" "AII" "AP"
>
> Why is that?
>
> I was thinking that I was creating a new data frame with only AID as a
> level for influencia.
>
> How can I make a complete new object with only the observations for
> "AID" and that the only level for influencia is indeed "AID"?
>
> Best,
>
> Manuel
>
>
-- 
Sarah Goslee
http://www.functionaldiversity.org

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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Roman Luštrik
You can also use droplevels() on your new object (as of R 2.12).

Cheers,
Roman



On Sun, Apr 24, 2011 at 3:42 PM, Christian Parker  wrote:

> You are creating a new object, but the columns that are stored as factors
> are not being 'refactored' so you are retaining the original list of levels.
> To fix this you can use the factor function after you subset
>
> pa2 = subset(pa, influencia=="AID")
> pa2$influencia<-as.factor(pa2$influencia)
>
>
>
> On Apr 24, 2011, at 6:04 AM, Manuel Spínola  wrote:
>
> > Dear list members,
> >
> > I have a question regarding too subsetting a data set in R.
> >
> > I created an object for my data:
> >
> >> pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
> >
> >> levels(pa$influencia)
> > [1] "AID" "AII" "AP"
> >
> > The object has 3 levels for influencia (AP, AID, AII)
> >
> > Now I subset only observations with influencia = "AID"
> >
> >> pa2 = subset(pa, influencia=="AID")
> >
> > but if I ask for the levels of influencia still show me the 3 levels,
> > AP, AID, AII.
> >
> >> levels(pa2$influencia)
> > [1] "AID" "AII" "AP"
> >
> > Why is that?
> >
> > I was thinking that I was creating a new data frame with only AID as a
> > level for influencia.
> >
> > How can I make a complete new object with only the observations for
> > "AID" and that the only level for influencia is indeed "AID"?
> >
> > Best,
> >
> > Manuel
> >
> >
> >
> >
> > --
> > *Manuel Spínola, Ph.D.*
> > Instituto Internacional en Conservación y Manejo de Vida Silvestre
> > Universidad Nacional
> > Apartado 1350-3000
> > Heredia
> > COSTA RICA
> > mspin...@una.ac.cr
> > mspinol...@gmail.com
> > Teléfono: (506) 2277-3598
> > Fax: (506) 2237-7036
> > Personal website: Lobito de río
> > 
> > Institutional website: ICOMVIS 
> >
> >[[alternative HTML version deleted]]
> >
> > ___
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> > R-sig-ecology@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
>
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>



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Re: [R-sig-eco] subsetting data in R

2011-04-24 Thread Christian Parker
You are creating a new object, but the columns that are stored as factors are 
not being 'refactored' so you are retaining the original list of levels. To fix 
this you can use the factor function after you subset

pa2 = subset(pa, influencia=="AID")
pa2$influencia<-as.factor(pa2$influencia)



On Apr 24, 2011, at 6:04 AM, Manuel Spínola  wrote:

> Dear list members,
> 
> I have a question regarding too subsetting a data set in R.
> 
> I created an object for my data:
> 
>> pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)
> 
>> levels(pa$influencia)
> [1] "AID" "AII" "AP"
> 
> The object has 3 levels for influencia (AP, AID, AII)
> 
> Now I subset only observations with influencia = "AID"
> 
>> pa2 = subset(pa, influencia=="AID")
> 
> but if I ask for the levels of influencia still show me the 3 levels, 
> AP, AID, AII.
> 
>> levels(pa2$influencia)
> [1] "AID" "AII" "AP"
> 
> Why is that?
> 
> I was thinking that I was creating a new data frame with only AID as a 
> level for influencia.
> 
> How can I make a complete new object with only the observations for 
> "AID" and that the only level for influencia is indeed "AID"?
> 
> Best,
> 
> Manuel
> 
> 
> 
> 
> -- 
> *Manuel Spínola, Ph.D.*
> Instituto Internacional en Conservación y Manejo de Vida Silvestre
> Universidad Nacional
> Apartado 1350-3000
> Heredia
> COSTA RICA
> mspin...@una.ac.cr
> mspinol...@gmail.com
> Teléfono: (506) 2277-3598
> Fax: (506) 2237-7036
> Personal website: Lobito de río 
> 
> Institutional website: ICOMVIS 
> 
>[[alternative HTML version deleted]]
> 
> ___
> R-sig-ecology mailing list
> R-sig-ecology@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology

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[R-sig-eco] subsetting data in R

2011-04-24 Thread Manuel Spínola
Dear list members,

I have a question regarding too subsetting a data set in R.

I created an object for my data:

 >pa = read.csv("espec_indic.csv", header = T, sep=",", check.names = F)

 > levels(pa$influencia)
[1] "AID" "AII" "AP"

The object has 3 levels for influencia (AP, AID, AII)

Now I subset only observations with influencia = "AID"

 >pa2 = subset(pa, influencia=="AID")

but if I ask for the levels of influencia still show me the 3 levels, 
AP, AID, AII.

 > levels(pa2$influencia)
[1] "AID" "AII" "AP"

Why is that?

I was thinking that I was creating a new data frame with only AID as a 
level for influencia.

How can I make a complete new object with only the observations for 
"AID" and that the only level for influencia is indeed "AID"?

Best,

Manuel




-- 
*Manuel Spínola, Ph.D.*
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspin...@una.ac.cr
mspinol...@gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036
Personal website: Lobito de río 

Institutional website: ICOMVIS 

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