Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and 'd2' in rows
and 'control' and 'sample' in columns. Is there a function for doing this
easily?
Thank you in advance.
Wendy
--
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reshape a matrix
9 messages · wendy, David Winsemius, Rolf Turner +2 more
On 20.08.2011 17:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and 'd2' in rows
and 'control' and 'sample' in columns. Is there a function for doing this
easily?
See ?reshape reshape(data=dataframe, idvar="A", timevar="B", direction="wide") Uwe Ligges
Thank you in advance. Wendy -- View this message in context: http://r.789695.n4.nabble.com/reshape-a-matrix-tp3757179p3757179.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at 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.
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
On 20.08.2011 17:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and
'd2' in rows
and 'control' and 'sample' in columns. Is there a function for
doing this
easily?
See ?reshape reshape(data=dataframe, idvar="A", timevar="B", direction="wide") Uwe Ligges
Many people have experienced problems understanding the mechanics of
the base function 'reshape'. If you do not and if do continue to use
it, you would be doing the world a great service by writing a tutorial
manual with a bunch of worked examples. I have never found a tutorial
that clarified how I should use it in the variety of situations where
I have needed it.
So Hadley wrote an alternate facility ... the reshape package that
does not have a reshape function in it but rather two functions 'melt'
and 'cast'. Your data is all ready "molten", i.e. it is in the long
format (in the terminology of the base reshape function) with
identifier values in each row and a single column of values.
> library(reshape)
> cast(dataframe,A~B)
Using C as value column. Use the value argument to cast to override
this choice
A control sample
1 d0 1e+05 1e+05
2 d1 2e+02 3e+02
3 d2 4e+02 5e+02
Basically the cast formula keeps the LHS variables in the rows and hte
RHD variables get arranges in columns. (For reasons that are unclear
to me the dataframe argument was placed first when using positional
argument passing, unlike most other formula methods in R.)
David Winsemius, MD West Hartford, CT
On 20.08.2011 19:04, David Winsemius wrote:
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
On 20.08.2011 17:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and 'd2'
in rows
and 'control' and 'sample' in columns. Is there a function for doing
this
easily?
See ?reshape reshape(data=dataframe, idvar="A", timevar="B", direction="wide") Uwe Ligges
Many people have experienced problems understanding the mechanics of the base function 'reshape'. If you do not and if do continue to use it, you would be doing the world a great service by writing a tutorial manual with a bunch of worked examples. I have never found a tutorial that clarified how I should use it in the variety of situations where I have needed it.
David, I think there are some good examples on the help page. What is missing? What is not clearly explained? If a longer tutorial is needed, that may be an article for the R Help Desk in The R Journal. Anybody volunteering? Best, Uwe
So Hadley wrote an alternate facility ... the reshape package that does not have a reshape function in it but rather two functions 'melt' and 'cast'.
> > Your data is all ready "molten", i.e. it is in the long format
(in the terminology of the base reshape function) with identifier values in each row and a single column of values.
> library(reshape) > cast(dataframe,A~B)
Using C as value column. Use the value argument to cast to override this choice A control sample 1 d0 1e+05 1e+05 2 d1 2e+02 3e+02 3 d2 4e+02 5e+02 Basically the cast formula keeps the LHS variables in the rows and hte RHD variables get arranges in columns. (For reasons that are unclear to me the dataframe argument was placed first when using positional argument passing, unlike most other formula methods in R.)
On Aug 20, 2011, at 1:21 PM, Uwe Ligges wrote:
On 20.08.2011 19:04, David Winsemius wrote:
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
On 20.08.2011 17:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and
'd2'
in rows
and 'control' and 'sample' in columns. Is there a function for
doing
this
easily?
See ?reshape reshape(data=dataframe, idvar="A", timevar="B", direction="wide") Uwe Ligges
Many people have experienced problems understanding the mechanics of the base function 'reshape'. If you do not and if do continue to use it, you would be doing the world a great service by writing a tutorial manual with a bunch of worked examples. I have never found a tutorial that clarified how I should use it in the variety of situations where I have needed it.
David, I think there are some good examples on the help page. What is missing? What is not clearly explained?
The stumbling blocks I have encountered are in trying to figure out which of the multiple arguments are needed a) in going from wide to long and b) in going from long to wide, c) and what are the reasons for the various error messages I provoke . I am almost never able to do it correctly on the first try and rarely able to do it even on the fourth try. I bought Spector's book in hopes of understanding it better, but his efforts did not take root in my brain. In the instance above, how would I have know how to apply the help page description of timevar (below) to this problem? timevar the variable in long format that differentiates multiple records from the same group or individual. To my reading that does not distinguish the purpose of 'timevar' from the purpose of 'idvar' and then reading the 'idvar' definition just below it does not help at all.
David. > If a longer tutorial is needed, that may be an article for the R > Help Desk in The R Journal. Anybody volunteering? > > Best, > Uwe > > >> >> So Hadley wrote an alternate facility ... the reshape package that >> does >> not have a reshape function in it but rather two functions 'melt' and >> 'cast'. > > > > Your data is all ready "molten", i.e. it is in the long format >> (in the terminology of the base reshape function) with identifier >> values >> in each row and a single column of values. >> >> > library(reshape) >> > cast(dataframe,A~B) >> Using C as value column. Use the value argument to cast to override >> this >> choice >> A control sample >> 1 d0 1e+05 1e+05 >> 2 d1 2e+02 3e+02 >> 3 d2 4e+02 5e+02 >> >> Basically the cast formula keeps the LHS variables in the rows and >> hte >> RHD variables get arranges in columns. (For reasons that are >> unclear to >> me the dataframe argument was placed first when using positional >> argument passing, unlike most other formula methods in R.) David Winsemius, MD West Hartford, CT
On Aug 20, 2011, at 1:39 PM, David Winsemius wrote:
On Aug 20, 2011, at 1:21 PM, Uwe Ligges wrote:
On 20.08.2011 19:04, David Winsemius wrote:
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
On 20.08.2011 17:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and
'd2'
in rows
and 'control' and 'sample' in columns. Is there a function for
doing
this
easily?
See ?reshape reshape(data=dataframe, idvar="A", timevar="B", direction="wide") Uwe Ligges
Many people have experienced problems understanding the mechanics of the base function 'reshape'. If you do not and if do continue to use it, you would be doing the world a great service by writing a tutorial manual with a bunch of worked examples. I have never found a tutorial that clarified how I should use it in the variety of situations where I have needed it.
David, I think there are some good examples on the help page. What is missing? What is not clearly explained?
The stumbling blocks I have encountered are in trying to figure out which of the multiple arguments are needed a) in going from wide to long and b) in going from long to wide, c) and what are the reasons for the various error messages I provoke . I am almost never able to do it correctly on the first try and rarely able to do it even on the fourth try. I bought Spector's book in hopes of understanding it better, but his efforts did not take root in my brain. In the instance above, how would I have know how to apply the help page description of timevar (below) to this problem? timevar the variable in long format that differentiates multiple records from the same group or individual.
I'm wondering it this would be clearer (if it is correct): timevar the variable in long format that order multiple records which vary within the same groups or individual specified in "idvar".
David > > To my reading that does not distinguish the purpose of 'timevar' > from the purpose of 'idvar' and then reading the 'idvar' definition > just below it does not help at all. > > -- > David. > > >> If a longer tutorial is needed, that may be an article for the R >> Help Desk in The R Journal. Anybody volunteering? >> >> Best, >> Uwe >> >> >>> >>> So Hadley wrote an alternate facility ... the reshape package that >>> does >>> not have a reshape function in it but rather two functions 'melt' >>> and >>> 'cast'. >> > >> > Your data is all ready "molten", i.e. it is in the long format >>> (in the terminology of the base reshape function) with identifier >>> values >>> in each row and a single column of values. >>> >>> > library(reshape) >>> > cast(dataframe,A~B) >>> Using C as value column. Use the value argument to cast to >>> override this >>> choice >>> A control sample >>> 1 d0 1e+05 1e+05 >>> 2 d1 2e+02 3e+02 >>> 3 d2 4e+02 5e+02 >>> >>> Basically the cast formula keeps the LHS variables in the rows and >>> hte >>> RHD variables get arranges in columns. (For reasons that are >>> unclear to >>> me the dataframe argument was placed first when using positional >>> argument passing, unlike most other formula methods in R.) > > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > R-help at 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. David Winsemius, MD West Hartford, CT
On 21/08/11 03:04, Wendy wrote:
Hi all,
I have a data.frame like following
A<-c('d0','d0','d1','d1','d2','d2')
B<-rep(c('control','sample'),3)
C<-c(rep(100000,2),200,300,400,500)
dataframe<-data.frame(A,B,C)
I want to reshape the matrix, so the matrix with 'd0', 'd1' and 'd2' in rows
and 'control' and 'sample' in columns. Is there a function for doing this
easily?
Your question has been answered .... But if you remember that a *matrix*
and a *data frame* are ***NOT*** the same thing, you'll get into a lot less
trouble. Why do you think there are two *different* terms for these sorts
of object if they are the same thing? Psigh!!!
cheers,
Rolf Turner
At 18:21 20/08/2011, Uwe Ligges wrote:
On 20.08.2011 19:04, David Winsemius wrote:
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
[snip original problem]
David, I think there are some good examples on the help page. What is missing? What is not clearly explained? If a longer tutorial is needed, that may be an article for the R Help Desk in The R Journal. Anybody volunteering?
Uwe I think the problem is that those of us who do not understand are in such a state of ignorance that we do not know what it is that we do not understand. I have resigned myself to the realisation that there are a very small number of things about R which I shall never understand and always solve by trial and error and the parameterisation of reshape is the leading example (closely followed by backslashes). I do not think the writers of the documentation are at fault here, it is either just inherently difficult to understand or my cortex is wired up inappropriately.
Best, Uwe
So Hadley wrote an alternate facility ... the reshape package that does not have a reshape function in it but rather two functions 'melt' and 'cast'. Your data is all ready "molten", i.e. it is in the long format (in the terminology of the base reshape function) with identifier values in each row and a single column of values.
> library(reshape) > cast(dataframe,A~B)
Using C as value column. Use the value argument to cast to override this choice A control sample 1 d0 1e+05 1e+05 2 d1 2e+02 3e+02 3 d2 4e+02 5e+02 Basically the cast formula keeps the LHS variables in the rows and hte RHD variables get arranges in columns. (For reasons that are unclear to me the dataframe argument was placed first when using positional argument passing, unlike most other formula methods in R.)
Michael Dewey info at aghmed.fsnet.co.uk http://www.aghmed.fsnet.co.uk/home.html
On 21.08.2011 12:54, Michael Dewey wrote:
At 18:21 20/08/2011, Uwe Ligges wrote:
On 20.08.2011 19:04, David Winsemius wrote:
On Aug 20, 2011, at 12:32 PM, Uwe Ligges wrote:
[snip original problem]
David, I think there are some good examples on the help page. What is missing? What is not clearly explained? If a longer tutorial is needed, that may be an article for the R Help Desk in The R Journal. Anybody volunteering?
Uwe I think the problem is that those of us who do not understand are in such a state of ignorance that we do not know what it is that we do not understand. I have resigned myself to the realisation that there are a very small number of things about R which I shall never understand and always solve by trial and error and the parameterisation of reshape is the leading example (closely followed by backslashes). I do not think the writers of the documentation are at fault here, it is either just inherently difficult to understand or my cortex is wired up inappropriately.
In think tha major problem is that stuff like "id" and "time" etc. may be misleading, if they do not fit to the context. Don't believe I do things correct right away here. Nevertheless, improving the wording of the reshape() documentation is not easy at all if we want to be precise. Maybe we find another volunteer or I find some time to write a short column for the next issue of The R Journal. Best wishes, Uwe
Best, Uwe
So Hadley wrote an alternate facility ... the reshape package that does not have a reshape function in it but rather two functions 'melt' and 'cast'. Your data is all ready "molten", i.e. it is in the long format (in the terminology of the base reshape function) with identifier values in each row and a single column of values.
library(reshape) cast(dataframe,A~B)
Using C as value column. Use the value argument to cast to override this choice A control sample 1 d0 1e+05 1e+05 2 d1 2e+02 3e+02 3 d2 4e+02 5e+02 Basically the cast formula keeps the LHS variables in the rows and hte RHD variables get arranges in columns. (For reasons that are unclear to me the dataframe argument was placed first when using positional argument passing, unlike most other formula methods in R.)
Michael Dewey info at aghmed.fsnet.co.uk http://www.aghmed.fsnet.co.uk/home.html