Message-ID: <47ECB7DC.1030707@bitwrit.com.au>
Date: 2008-03-28T09:18:20Z
From: Jim Lemon
Subject: Converting a data frame to matrix
In-Reply-To: <c96452060803271743h11869c29t695a037567d1ed7a@mail.gmail.com>
Adrian Johnson wrote:
> Hello:
>
> I have a tab delim file with 100 rows and 100 columns.
>
> I have numerical values in this table. What I want is to create an image
> color map with color gradation.
>
> my values range from -5 to 0. max value is 0.
>
> to acheive this, I need to convert my data.frame into matrix.
>
> I tried following :
>
> mydf <- read.table('mytable',sep='\t',header=T)
> mydf1 <- mydf[,2:100]
> colnames(mydf1) <- as.character(mydf[,1])
>
> here comes the trouble:
>
> mymat <- as.matrix(mydf1)
>
> -- numerical values become character values. -1 becomes "-1"
>
> mymat <- data.matrix(mydf1)
>
> -- whole matrix is filled with 1,2 and 3.
>
> Is there any other way I can do this.
>
> say row names are city schools
> colnames are student names
>
Hi Adrian,
Have you looked at color2d.matplot in the plotrix package?
Jim