[R] Syntax Help for xyplot()

[Rich Shepard]

On Mon, 24 Oct 2011, B77S wrote:

> The following might not be exactly the way to do this, but see the package
> "reshape" and the line of code following your data:

   Thank you, B77S. Bert pointed me to reshape and reshape2. I'll read the
help pages for them before responding. I'll be out of the office all
tomorrow morning so it will be after lunch (PST) that I get back to this.

> df <- structure(list(site = structure(c(1L, 1L, 2L, 4L, 2L, 2L, 2L,
> 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("BC-0.5", "BC-2", "BC-3",
> "BC-4"), class = "factor"), sampdate = structure(c(11L, 11L,
> 5L, 12L, 7L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 8L), .Label = c("1994-01-20",
> "1994-02-17", "1994-03-24", "1994-06-13", "1994-07-25", "1994-08-18",
> "1994-10-19", "1994-10-20", "1995-03-16", "1995-06-21", "1996-06-02",
> "1996-08-23"), class = "factor"), param = structure(c(2L, 3L,
> 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("Cond",
> "SO4", "TDS"), class = "factor"), quant = c(194, 530, 826, 36,
> 848, 1795, 640, 406, 401, 441, 400, 393, 420, 438)), .Names = c("site",
> "sampdate", "param", "quant"), class = "data.frame", row.names = c("82",
> "83", "6903", "6905", "6977", "6980", "6983", "7833", "7838",
> "7847", "7854", "7866", "7871", "7877"))

   The sample helps.

   My base data frame has 47045 rows, 148 sites, 66 parameters, and 1056
distinct sample dates. I'm going to study reshape/reshape2 thoroughly as I
don't want to enter all those data by hand. :-)

Regards,

Rich