[R] Syntax Help for xyplot()

[Rich Shepard]

On Mon, 24 Oct 2011, B77S wrote:

> Why not format the data like this:
> site sampledate SO4 TDS NA Mg Cond Cl Ca

   Because I don't know how to reformat the base data frame (chemdata) to
achieve this.

> It seems to me that you summary doesn't make any sense.  Those quantiles
> are meaningless as they encompass all the parameters.  Am I missing
> something?

   One site/sampdate/param has one value associated with it.

>> 82    BC-0.5 1996-06-02   SO4  194.00
>> 83    BC-0.5 1996-06-02   TDS  530.00
>> 6903    BC-2 1994-07-25  Cond  826.00
>> 6905    BC-4 1996-08-23   SO4   36.00
>> 6977    BC-2 1994-10-19  Cond  848.00
>> 6980    BC-2 1995-03-16  Cond 1795.00
>> 6983    BC-2 1995-06-21  Cond  640.00
>> 7833    BC-3 1994-01-20  Cond  406.00
>> 7838    BC-3 1994-02-17  Cond  401.00
>> 7847    BC-3 1994-03-24  Cond  441.00
>> 7854    BC-3 1994-06-13  Cond  400.00
>> 7866    BC-3 1994-07-25  Cond  393.00
>> 7871    BC-3 1994-08-18  Cond  420.00
>> 7877    BC-3 1994-10-20  Cond  438.00

   I acknowledge that if the chemicals ('param') were in a vector, their associated
concentrations ('quant') in another vector following it, and both associated
with a site and sampdate life would be much better.

Thanks,

Rich