[R] Convert matrix to numeric

[Nordlund, Dan (DSHS/RDA)]

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Ken
> Sent: Wednesday, August 03, 2011 12:13 PM
> To: Jeffrey Joh
> Cc: <r-help at r-project.org>
> Subject: Re: [R] Convert matrix to numeric
> 
> How about
> Matrix[1:5,]=as.numeric(Matrix[1:5,])
> -Ken Hutchison
> 
> On Aug 3, 2554 BE, at 3:04 PM, Jeffrey Joh <johjeffrey at hotmail.com>
> wrote:
> 
> >
> > I have a matrix that looks like this:
> >
> >
> > structure(c("0.0376673981759913", "0.111066500741386", "1", "1103",
> > "18", "OPEN", "DEPR", "0.0404073656092023", "0.115186044704599",
> > "1", "719", "18", "OPEN", "DEPR", "0.0665342096693433",
> "0.197570061769498",
> > "1", "1103", "18", "OPEN", "DEPR", "0.119287147905722",
> "0.356427096010845",
> > "1", "1103", "18", "OPEN", "DEPR"), .Dim = c(7L, 4L), .Dimnames =
> list(
> >    c("Sn", "SlnC", "housenum", "date", "hour", "flue",
> "pressurization"
> >    ), c("10019.BLO", "1002.BLO", "10020.BLO", "10021.BLO")))
> >
> >
> >
> > How do I convert rows 1-5 to numeric?  I tried mode() <- "numeric"
> but that doesn't change anything.
> >

Ken,

You can't store the numeric values back in the matrix, because rows 6 and 7 contain character values.  Everything will just be converted back to character.  You need to create a new matrix for the numeric values.

Hope this is helpful,

Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA 98504-5204