R graphing unique rows in different graphs

Question

This group has been very helpful, I really appreciate all the help. You guys are awesome. I searched but could not find an answer. I have a data frame which incluces 1st column server names and others have different metrics. I would like to be able to use ggplot2 to go though the data frame and create charts based on unique rows (servernames). How can I do this given a large data set.

Here is a sample data set:

Hostname            Date          CPU Mem  cpu       avg        io       mem           
host1       2012-01-01 01:00:00   27.24   2.33       0.47       2.33     27.20
host1       2012-01-01 02:00:00   28.00  22.38      36.50      22.38     27.49
host2       2012-01-01 03:00:00   29.31   7.58      12.23       7.58     28.56
host2       2012-01-01 04:00:00   29.37   2.44       0.35       2.44     29.30
host3       2012-01-01 05:00:00   29.07   2.86       1.04       2.86     28.02
host3       2012-01-01 06:00:00   28.05   2.74       0.67       2.74     27.96

 > str(yy)
 List of 10
 $ Hostname  : Factor w/ 37 levels "host1",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ Date      : POSIXct[1:26088], format: "2012-01-01 01:00:00" "2012-01-01         
 02:00:00" "2012-01-01 03:00:00" "2012-01-01 04:00:00" ...
 $ variable  : chr [1:26088] "1:00:00" "2:00:00" "3:00:00" "4:00:00" ...
 $ 5         : num [1:26088] 27.2 28 29.3 29.4 29.1 ...
 $ 60        : num [1:26088] NA NA NA NA NA NA NA NA NA NA ...
 $ 61        : num [1:26088] NA NA NA NA NA NA NA NA NA NA ...
 $ CPUAVG    : num [1:26088] 2.33 22.38 7.58 2.44 2.86 ...
 $ CPUAVG+Sev: num [1:26088] 0.47 36.5 12.23 0.35 1.04 ...
 $ CPUMaximum: num [1:26088] 2.33 22.38 7.58 2.44 2.86 ...
 $ MemoryAVG : num [1:26088] 27.2 27.5 28.6 29.3 28 ...
- attr(*, "row.names")= int [1:26088] 1 2 3 4 5 6 7 8 9 10 ...
 - attr(*, "idvars")= chr [1:3] "Hostname" "Date" "variable"
 - attr(*, "rdimnames")=List of 2
 ..$ :'data.frame':    26088 obs. of  3 variables:
 .. ..$ Hostname: Factor w/ 37 levels "host1",..: 1 1 1 1 1 1 1 1 1 1 ...
 .. ..$ Date    : Factor w/ 31 levels "01/01/2012","01/02/2012",..: 1 1 1 1 1 1 1 1 
1    1 ...
 .. ..$ variable: Factor w/ 24 levels "Hour1","Hour2",..: 1 2 3 4 5 6 7 8 9 10 ...
 ..$ :'data.frame':    7 obs. of  1 variable:
.. ..$ MetricType: Factor w/ 7 levels "5","60","61",..: 1 2 3 4 5 6 7

Answer 1

Sounds like a facetting question to me. Here's an example. Updated with your data

# Dummy data    
x <- data.frame(
  hostname=rep(paste("host",1:3,sep=""),1000),
  date=as.Date(1:1000,origin="2005-01-01"),
  CPUMEM=rnorm(1000)+20,
  CPU=rnorm(1000)+10,
  avg=rnorm(1000)+10,
  io=rnorm(1000)+5,
  mem=rnorm(1000)+27)

x <- melt(x, c("hostname","date"))

ggplot(x, aes(date,value, color=variable)) + geom_line() + facet_grid(~hostname)