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How to transform the Matrix into the way I want it ???

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How to transform the Matrix into the way I want it ???

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Hi, R users,

I'm trying to transform a matrix A into B (see below). Anyone knows how to
do it in R? Thanks.

Matrix A (zone to zone travel time)

zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0

B:

from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5 z3 z1
4.3 z3 z2 2.5 z3 z3 0

The real matrix I have is much larger, with more than 2000 zones. But I
think it should be the same thing if I can transform A into B.

Thanks.

Garry

[[alternative HTML version deleted]]

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William Dunlap

Re: How to transform the Matrix into the way I want it ???

Reply Threaded

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Hongwei Dong
> Sent: Monday, November 09, 2009 2:24 PM
> To: R-help Forum
> Subject: [R] How to transform the Matrix into the way I want it ???
>
> Hi, R users,
>
> I'm trying to transform a matrix A into B (see below). Anyone
> knows how to
> do it in R? Thanks.
>
> Matrix A (zone to zone travel time)
>
> zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0
>
> B:
>
> from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2
> z3 2.5 z3 z1
> 4.3 z3 z2 2.5 z3 z3 0

Try
data.frame(From=rownames(A)[row(A)], To=colnames(A)[col(A)],
Time=as.vector(A))
You probably do not want a matrix because all of its elements
must have the same type, forcing Time to be character instead
of numeric.

E.g.,

> A<-rbind(Anacortes=c(Anacortes=0,Seattle=90,"Mount Vernon"=20),
+ Seattle=c(Anacortes=80, Seattle=0, "Mount Vernon"=60),
+ "Mount Vernon"=c(Anacortes=20,Seattle=70,"Mount Vernon"=0))
> data.frame(From=rownames(A)[row(A)], To=colnames(A)[col(A)],
Time=as.vector(A))
From To Time
1 Anacortes Anacortes 0
2 Seattle Anacortes 80
3 Mount Vernon Anacortes 20
4 Anacortes Seattle 90
5 Seattle Seattle 0
6 Mount Vernon Seattle 70
7 Anacortes Mount Vernon 20
8 Seattle Mount Vernon 60
9 Mount Vernon Mount Vernon 0

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com

>
> The real matrix I have is much larger, with more than 2000
> zones. But I
> think it should be the same thing if I can transform A into B.
>
> Thanks.
>
> Garry
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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.
>

______________________________________________
[hidden email] 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.

Nikhil Kaza-2

Re: How to transform the Matrix into the way I want it ???

Reply Threaded

In reply to this post by Hongwei Dong

This is not an answer to your question, but I have used SparseM
package to represent large travel time matrices efficiently.

?as.matrix.ssr

if the traveltime matrix is symmetric.

On 9 Nov 2009, at 5:24PM, Hongwei Dong wrote:

> Hi, R users,
>
> I'm trying to transform a matrix A into B (see below). Anyone knows
> how to
> do it in R? Thanks.
>
> Matrix A (zone to zone travel time)
>
> zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0
>
> B:
>
> from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5
> z3 z1
> 4.3 z3 z2 2.5 z3 z3 0
>
> The real matrix I have is much larger, with more than 2000 zones.
> But I
> think it should be the same thing if I can transform A into B.
>
> Thanks.
>
> Garry
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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

Re: How to transform the Matrix into the way I want it ???

Reply Threaded

In reply to this post by Hongwei Dong

On Nov 9, 2009, at 5:24 PM, Hongwei Dong wrote:

> ztz <- read.table(textConnection(" z1 z2 z3 \n z1 0 2.9 4.3 \n z2
2.9 0 2.5 \n z3 4.3 2.5 0"), header=T)
> ztz
z1 z2 z3
z1 0.0 2.9 4.3
z2 2.9 0.0 2.5
z3 4.3 2.5 0.0

> B:
>
> from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5
> z3 z1
> 4.3 z3 z2 2.5 z3 z3 0

Now taking some liberties with coercion:

> as.data.frame.table(ztz, responseName="Time")
Var1 Var2 Time
1 z1 z1 0.0
2 z2 z1 2.9
3 z3 z1 4.3
4 z1 z2 2.9
5 z2 z2 0.0
6 z3 z2 2.5
7 z1 z3 4.3
8 z2 z3 2.5
9 z3 z3 0.0

Or perhaps:

> data.frame(stack(as.data.frame(ztz)), From=colnames(ztz))
values ind From
1 0.0 z1 z1
2 2.9 z1 z2
3 4.3 z1 z3
4 2.9 z2 z1
5 0.0 z2 z2
6 2.5 z2 z3
7 4.3 z3 z1
8 2.5 z3 z2
9 0.0 z3 z3

>
> The real matrix I have is much larger, with more than 2000 zones.
> But I
> think it should be the same thing if I can transform A into B.
>
> Thanks.
>
> Garry
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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
Heritage Laboratories
West Hartford, CT

______________________________________________
[hidden email] 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.