Re: [R] how to fetch rows with certain characteristics
Try
> x <- read.table(textConnection(
+ "1.2 1
+ 1.2 1
+ 1.3 1
+ 1.5 1
+ 1.1 2
+ 1.2 2
+ 9.9 2
+ 0.1 3
+ 1.1 3
+ 1.9 3") )
> x.min <- tapply(x[,1], x[,2], min)
> x[x.min[x[,2]]==x[,1],]
V1 V2
[1,] 1.2 1
[2,] 1.2 1
[3,] 1.1 2
[4,] 0.1 3
2009/10/29 Ista Zahn
> I still don't understand. Please look at the example I provided in my
> last response. What is it that you want that my example does not do?
>
> On Thu, Oct 29, 2009 at 3:08 PM, Waverley @ Palo Alto
> wrote:
> > The reason %in% does not work is that there are might be values which
> > are not min in other class which are the same as the min of different
> > classes. In the example I provided before, this situation did not
> > exist. See the new example:
> >
> >> + 1.2 1
> >> + 1.3 1
> >> + 1.5 1
> >> + 1.1 2
> >> + 1.2 2
> >> + 9.9 2
> >> + 0.1 3
> >> + 1.1 3
> >> + 1.9 3
> >
> > if you are using %in%, then
> > 1.2 2
> > 1.1 3
> > will also show up in the final result.
> >
> >
> > That is why I need those row index of the min value of each class. If
> > I can get those, that would be best.
> > Thanks.
> >
> > On Thu, Oct 29, 2009 at 11:58 AM, Ista Zahn wrote:
> >> Hi,
> >> I guess I don't understand why you think %in% won't work.
> >>
> >>> x <- read.table(textConnection("1.2 1
> >> + 1.2 1
> >> + 1.3 1
> >> + 1.5 1
> >> + 2.1 2
> >> + 2.0 2
> >> + 9.9 2
> >> + 1.4 3
> >> + 1.8 3
> >> + 1.9 3") )
> >>> x <- as.matrix(x)
> >>> x.min <- tapply(x[,1], x[,2], min)
> >>> x[x[,1] %in% x.min,]
> >>> ## all matches
> >> V1 V2
> >> [1,] 1.2 1
> >> [2,] 1.2 1
> >> [3,] 2.0 2
> >> [4,] 1.4 3
> >>> ## unique matches
> >>> unique(x[x[,1] %in% x.min,])
> >> V1 V2
> >> [1,] 1.2 1
> >> [2,] 2.0 2
> >> [3,] 1.4 3
> >>
> >> -Ista
> >> On Thu, Oct 29, 2009 at 12:36 PM, Waverley @ Palo Alto
> >> wrote:
> >>> Thanks. That works.
> >>>
> >>> However, in my own case, there are more columns of other kinds of
> >>> data. So to me, it is more important to get the row index of those
> >>> that has the min values of particular column in particular class
> >>> (which is another column).
> >>>
> >>> Can you help more as how to get those row index? One issue is that for
> >>> some class they may share the same min value so that using %in% does
> >>> not work. My goal is to reduce the original matrix size and get the
> >>> result back in the original matrix format.
> >>>
> >>>
> >>> Thanks.
> >>>
> >>> On Wed, Oct 28, 2009 at 11:55 PM, Ista Zahn
> wrote:
> There are various ways, including
>
> x <- read.table(textConnection("1.2 1
> + 1.3 1
> + 1.3 1
> + 1.5 1
> + 2.1 2
> + 2.0 2
> + 9.9 2
> + 1.4 3
> + 1.8 3
> + 1.9 3") )
>
> x <- as.matrix(x)
>
> x.min <- cbind(tapply(x[,1], x[,2], min), unique(x[,"V2"]))
>
> Most of that is just formatting it in the way you requested. All you
> need to compute the values is
>
> tapply(x[,1], x[,2], min)
>
> -Ista
>
> On Thu, Oct 29, 2009 at 1:47 AM, Waverley @ Palo Alto
> wrote:
> > Hi,
> >
> > I have a matrix, first column is of certain values, second column is
> > the class labels or a factor.
> > e.g.
> >
> > 1.2 1
> > 1.3 1
> > 1.3 1
> > 1.5 1
> > 2.1 2
> > 2.0 2
> > 9.9 2
> > 1.4 3
> > 1.8 3
> > 1.9 3
> >
> > I want to find out what is the min values of column 1 for each
> > corresponding class (column 2). For the above example, I want to
> > return a matrix of
> > 1.2 1
> > 2.0 2
> > 1.3 3
> >
> > Can someone suggest how to code for that? The second column can be
> of
> > characters.
> >
> > Thanks much.
> >
> >
> > --
> > Waverley @ Palo Alto
> >
> > __
> > 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.
> >
>
>
>
> --
> Ista Zahn
> Graduate student
> University of Rochester
> Department of Clinical and Social Psychology
> http://yourpsyche.org
>
> >>>
> >>>
> >>>
> >>> --
> >>> Waverley @ Palo Alto
> >>>
> >>
> >>
> >>
> >> --
> >> Ista Zahn
> >> Graduate student
> >> University of Rochester
> >> Department of Clinical and Social Psychology
> >> http://yourpsyche.org
> >>
> >
> >
> >
> > --
> > Waverley @ Palo Alto
> >
>
>
>
> --
> Ista Zahn
> Graduate student
> University of Rochester
> Department of Clinical and Social Psychology
> http://yourpsyche.org
>
> __
> 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] how to fetch rows with certain characteristics
I still don't understand. Please look at the example I provided in my
last response. What is it that you want that my example does not do?
On Thu, Oct 29, 2009 at 3:08 PM, Waverley @ Palo Alto
wrote:
> The reason %in% does not work is that there are might be values which
> are not min in other class which are the same as the min of different
> classes. In the example I provided before, this situation did not
> exist. See the new example:
>
>> + 1.2 1
>> + 1.3 1
>> + 1.5 1
>> + 1.1 2
>> + 1.2 2
>> + 9.9 2
>> + 0.1 3
>> + 1.1 3
>> + 1.9 3
>
> if you are using %in%, then
> 1.2 2
> 1.1 3
> will also show up in the final result.
>
>
> That is why I need those row index of the min value of each class. If
> I can get those, that would be best.
> Thanks.
>
> On Thu, Oct 29, 2009 at 11:58 AM, Ista Zahn wrote:
>> Hi,
>> I guess I don't understand why you think %in% won't work.
>>
>>> x <- read.table(textConnection("1.2 1
>> + 1.2 1
>> + 1.3 1
>> + 1.5 1
>> + 2.1 2
>> + 2.0 2
>> + 9.9 2
>> + 1.4 3
>> + 1.8 3
>> + 1.9 3") )
>>> x <- as.matrix(x)
>>> x.min <- tapply(x[,1], x[,2], min)
>>> x[x[,1] %in% x.min,]
>>> ## all matches
>> V1 V2
>> [1,] 1.2 1
>> [2,] 1.2 1
>> [3,] 2.0 2
>> [4,] 1.4 3
>>> ## unique matches
>>> unique(x[x[,1] %in% x.min,])
>> V1 V2
>> [1,] 1.2 1
>> [2,] 2.0 2
>> [3,] 1.4 3
>>
>> -Ista
>> On Thu, Oct 29, 2009 at 12:36 PM, Waverley @ Palo Alto
>> wrote:
>>> Thanks. That works.
>>>
>>> However, in my own case, there are more columns of other kinds of
>>> data. So to me, it is more important to get the row index of those
>>> that has the min values of particular column in particular class
>>> (which is another column).
>>>
>>> Can you help more as how to get those row index? One issue is that for
>>> some class they may share the same min value so that using %in% does
>>> not work. My goal is to reduce the original matrix size and get the
>>> result back in the original matrix format.
>>>
>>>
>>> Thanks.
>>>
>>> On Wed, Oct 28, 2009 at 11:55 PM, Ista Zahn wrote:
There are various ways, including
x <- read.table(textConnection("1.2 1
+ 1.3 1
+ 1.3 1
+ 1.5 1
+ 2.1 2
+ 2.0 2
+ 9.9 2
+ 1.4 3
+ 1.8 3
+ 1.9 3") )
x <- as.matrix(x)
x.min <- cbind(tapply(x[,1], x[,2], min), unique(x[,"V2"]))
Most of that is just formatting it in the way you requested. All you
need to compute the values is
tapply(x[,1], x[,2], min)
-Ista
On Thu, Oct 29, 2009 at 1:47 AM, Waverley @ Palo Alto
wrote:
> Hi,
>
> I have a matrix, first column is of certain values, second column is
> the class labels or a factor.
> e.g.
>
> 1.2 1
> 1.3 1
> 1.3 1
> 1.5 1
> 2.1 2
> 2.0 2
> 9.9 2
> 1.4 3
> 1.8 3
> 1.9 3
>
> I want to find out what is the min values of column 1 for each
> corresponding class (column 2). For the above example, I want to
> return a matrix of
> 1.2 1
> 2.0 2
> 1.3 3
>
> Can someone suggest how to code for that? The second column can be of
> characters.
>
> Thanks much.
>
>
> --
> Waverley @ Palo Alto
>
> __
> 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.
>
--
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org
>>>
>>>
>>>
>>> --
>>> Waverley @ Palo Alto
>>>
>>
>>
>>
>> --
>> Ista Zahn
>> Graduate student
>> University of Rochester
>> Department of Clinical and Social Psychology
>> http://yourpsyche.org
>>
>
>
>
> --
> Waverley @ Palo Alto
>
--
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org
__
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] how to fetch rows with certain characteristics
The reason %in% does not work is that there are might be values which
are not min in other class which are the same as the min of different
classes. In the example I provided before, this situation did not
exist. See the new example:
> + 1.2 1
> + 1.3 1
> + 1.5 1
> + 1.1 2
> + 1.2 2
> + 9.9 2
> + 0.1 3
> + 1.1 3
> + 1.9 3
if you are using %in%, then
1.2 2
1.1 3
will also show up in the final result.
That is why I need those row index of the min value of each class. If
I can get those, that would be best.
Thanks.
On Thu, Oct 29, 2009 at 11:58 AM, Ista Zahn wrote:
> Hi,
> I guess I don't understand why you think %in% won't work.
>
>> x <- read.table(textConnection("1.2 1
> + 1.2 1
> + 1.3 1
> + 1.5 1
> + 2.1 2
> + 2.0 2
> + 9.9 2
> + 1.4 3
> + 1.8 3
> + 1.9 3") )
>> x <- as.matrix(x)
>> x.min <- tapply(x[,1], x[,2], min)
>> x[x[,1] %in% x.min,]
>> ## all matches
> V1 V2
> [1,] 1.2 1
> [2,] 1.2 1
> [3,] 2.0 2
> [4,] 1.4 3
>> ## unique matches
>> unique(x[x[,1] %in% x.min,])
> V1 V2
> [1,] 1.2 1
> [2,] 2.0 2
> [3,] 1.4 3
>
> -Ista
> On Thu, Oct 29, 2009 at 12:36 PM, Waverley @ Palo Alto
> wrote:
>> Thanks. That works.
>>
>> However, in my own case, there are more columns of other kinds of
>> data. So to me, it is more important to get the row index of those
>> that has the min values of particular column in particular class
>> (which is another column).
>>
>> Can you help more as how to get those row index? One issue is that for
>> some class they may share the same min value so that using %in% does
>> not work. My goal is to reduce the original matrix size and get the
>> result back in the original matrix format.
>>
>>
>> Thanks.
>>
>> On Wed, Oct 28, 2009 at 11:55 PM, Ista Zahn wrote:
>>> There are various ways, including
>>>
>>> x <- read.table(textConnection("1.2 1
>>> + 1.3 1
>>> + 1.3 1
>>> + 1.5 1
>>> + 2.1 2
>>> + 2.0 2
>>> + 9.9 2
>>> + 1.4 3
>>> + 1.8 3
>>> + 1.9 3") )
>>>
>>> x <- as.matrix(x)
>>>
>>> x.min <- cbind(tapply(x[,1], x[,2], min), unique(x[,"V2"]))
>>>
>>> Most of that is just formatting it in the way you requested. All you
>>> need to compute the values is
>>>
>>> tapply(x[,1], x[,2], min)
>>>
>>> -Ista
>>>
>>> On Thu, Oct 29, 2009 at 1:47 AM, Waverley @ Palo Alto
>>> wrote:
Hi,
I have a matrix, first column is of certain values, second column is
the class labels or a factor.
e.g.
1.2 1
1.3 1
1.3 1
1.5 1
2.1 2
2.0 2
9.9 2
1.4 3
1.8 3
1.9 3
I want to find out what is the min values of column 1 for each
corresponding class (column 2). For the above example, I want to
return a matrix of
1.2 1
2.0 2
1.3 3
Can someone suggest how to code for that? The second column can be of
characters.
Thanks much.
--
Waverley @ Palo Alto
__
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.
>>>
>>>
>>>
>>> --
>>> Ista Zahn
>>> Graduate student
>>> University of Rochester
>>> Department of Clinical and Social Psychology
>>> http://yourpsyche.org
>>>
>>
>>
>>
>> --
>> Waverley @ Palo Alto
>>
>
>
>
> --
> Ista Zahn
> Graduate student
> University of Rochester
> Department of Clinical and Social Psychology
> http://yourpsyche.org
>
--
Waverley @ Palo Alto
__
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] how to fetch rows with certain characteristics
Hi,
I guess I don't understand why you think %in% won't work.
> x <- read.table(textConnection("1.2 1
+ 1.2 1
+ 1.3 1
+ 1.5 1
+ 2.1 2
+ 2.0 2
+ 9.9 2
+ 1.4 3
+ 1.8 3
+ 1.9 3") )
> x <- as.matrix(x)
> x.min <- tapply(x[,1], x[,2], min)
> x[x[,1] %in% x.min,]
> ## all matches
V1 V2
[1,] 1.2 1
[2,] 1.2 1
[3,] 2.0 2
[4,] 1.4 3
> ## unique matches
> unique(x[x[,1] %in% x.min,])
V1 V2
[1,] 1.2 1
[2,] 2.0 2
[3,] 1.4 3
-Ista
On Thu, Oct 29, 2009 at 12:36 PM, Waverley @ Palo Alto
wrote:
> Thanks. That works.
>
> However, in my own case, there are more columns of other kinds of
> data. So to me, it is more important to get the row index of those
> that has the min values of particular column in particular class
> (which is another column).
>
> Can you help more as how to get those row index? One issue is that for
> some class they may share the same min value so that using %in% does
> not work. My goal is to reduce the original matrix size and get the
> result back in the original matrix format.
>
>
> Thanks.
>
> On Wed, Oct 28, 2009 at 11:55 PM, Ista Zahn wrote:
>> There are various ways, including
>>
>> x <- read.table(textConnection("1.2 1
>> + 1.3 1
>> + 1.3 1
>> + 1.5 1
>> + 2.1 2
>> + 2.0 2
>> + 9.9 2
>> + 1.4 3
>> + 1.8 3
>> + 1.9 3") )
>>
>> x <- as.matrix(x)
>>
>> x.min <- cbind(tapply(x[,1], x[,2], min), unique(x[,"V2"]))
>>
>> Most of that is just formatting it in the way you requested. All you
>> need to compute the values is
>>
>> tapply(x[,1], x[,2], min)
>>
>> -Ista
>>
>> On Thu, Oct 29, 2009 at 1:47 AM, Waverley @ Palo Alto
>> wrote:
>>> Hi,
>>>
>>> I have a matrix, first column is of certain values, second column is
>>> the class labels or a factor.
>>> e.g.
>>>
>>> 1.2 1
>>> 1.3 1
>>> 1.3 1
>>> 1.5 1
>>> 2.1 2
>>> 2.0 2
>>> 9.9 2
>>> 1.4 3
>>> 1.8 3
>>> 1.9 3
>>>
>>> I want to find out what is the min values of column 1 for each
>>> corresponding class (column 2). For the above example, I want to
>>> return a matrix of
>>> 1.2 1
>>> 2.0 2
>>> 1.3 3
>>>
>>> Can someone suggest how to code for that? The second column can be of
>>> characters.
>>>
>>> Thanks much.
>>>
>>>
>>> --
>>> Waverley @ Palo Alto
>>>
>>> __
>>> 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.
>>>
>>
>>
>>
>> --
>> Ista Zahn
>> Graduate student
>> University of Rochester
>> Department of Clinical and Social Psychology
>> http://yourpsyche.org
>>
>
>
>
> --
> Waverley @ Palo Alto
>
--
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org
__
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] how to fetch rows with certain characteristics
Thanks. That works.
However, in my own case, there are more columns of other kinds of
data. So to me, it is more important to get the row index of those
that has the min values of particular column in particular class
(which is another column).
Can you help more as how to get those row index? One issue is that for
some class they may share the same min value so that using %in% does
not work. My goal is to reduce the original matrix size and get the
result back in the original matrix format.
Thanks.
On Wed, Oct 28, 2009 at 11:55 PM, Ista Zahn wrote:
> There are various ways, including
>
> x <- read.table(textConnection("1.2 1
> + 1.3 1
> + 1.3 1
> + 1.5 1
> + 2.1 2
> + 2.0 2
> + 9.9 2
> + 1.4 3
> + 1.8 3
> + 1.9 3") )
>
> x <- as.matrix(x)
>
> x.min <- cbind(tapply(x[,1], x[,2], min), unique(x[,"V2"]))
>
> Most of that is just formatting it in the way you requested. All you
> need to compute the values is
>
> tapply(x[,1], x[,2], min)
>
> -Ista
>
> On Thu, Oct 29, 2009 at 1:47 AM, Waverley @ Palo Alto
> wrote:
>> Hi,
>>
>> I have a matrix, first column is of certain values, second column is
>> the class labels or a factor.
>> e.g.
>>
>> 1.2 1
>> 1.3 1
>> 1.3 1
>> 1.5 1
>> 2.1 2
>> 2.0 2
>> 9.9 2
>> 1.4 3
>> 1.8 3
>> 1.9 3
>>
>> I want to find out what is the min values of column 1 for each
>> corresponding class (column 2). For the above example, I want to
>> return a matrix of
>> 1.2 1
>> 2.0 2
>> 1.3 3
>>
>> Can someone suggest how to code for that? The second column can be of
>> characters.
>>
>> Thanks much.
>>
>>
>> --
>> Waverley @ Palo Alto
>>
>> __
>> 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.
>>
>
>
>
> --
> Ista Zahn
> Graduate student
> University of Rochester
> Department of Clinical and Social Psychology
> http://yourpsyche.org
>
--
Waverley @ Palo Alto
__
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] how to fetch rows with certain characteristics
tapply(x, y, min) where x is the vector of numbers and y the vector of class labels. Best, -- Wolfgang Viechtbauerhttp://www.wvbauer.com/ Department of Methodology and StatisticsTel: +31 (0)43 388-2277 School for Public Health and Primary Care Office Location: Maastricht University, P.O. Box 616 Room B2.01 (second floor) 6200 MD Maastricht, The Netherlands Debyeplein 1 (Randwyck) From: r-help-boun...@r-project.org [r-help-boun...@r-project.org] On Behalf Of Waverley @ Palo Alto [waverley.paloa...@gmail.com] Sent: Thursday, October 29, 2009 6:47 AM To: r-help Subject: [R] how to fetch rows with certain characteristics Hi, I have a matrix, first column is of certain values, second column is the class labels or a factor. e.g. 1.2 1 1.3 1 1.3 1 1.5 1 2.1 2 2.0 2 9.9 2 1.4 3 1.8 3 1.9 3 I want to find out what is the min values of column 1 for each corresponding class (column 2). For the above example, I want to return a matrix of 1.2 1 2.0 2 1.3 3 Can someone suggest how to code for that? The second column can be of characters. Thanks much. -- Waverley @ Palo Alto __ 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-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] how to fetch rows with certain characteristics
Hi, I have a matrix, first column is of certain values, second column is the class labels or a factor. e.g. 1.2 1 1.3 1 1.3 1 1.5 1 2.1 2 2.0 2 9.9 2 1.4 3 1.8 3 1.9 3 I want to find out what is the min values of column 1 for each corresponding class (column 2). For the above example, I want to return a matrix of 1.2 1 2.0 2 1.3 3 Can someone suggest how to code for that? The second column can be of characters. Thanks much. -- Waverley @ Palo Alto __ 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.
