On Thu, 27 Oct 2011, Dennis Murphy wrote:
# Define param so that all of its levels are represented:
tds.a <- within(tds.a, {
param = factor(param, levels = c('TDS', 'Cond', 'Mg', 'Ca',
'Cl', 'Na', 'SO4'))
sampdate = as.Date(sampdate) } )
Dennis,
This produces an error:
tds.a <- within(tds.anal, {param = factor(param, levels = c('TDS', 'Cond',
'Mg', 'Ca', 'Cl', 'Na', 'SO4')) sampdate = as.Date(sampdate)})
Error: unexpected symbol in "tds.a <- within(tds.anal, {param =
factor(param, levels = c('TDS', 'Cond', 'Mg', 'Ca', 'Cl', 'Na', 'SO4'))
sampdate"
So I did the conversion and melting the long way:
tds.a <- tds.anal
tds.a$sampdate <- factor(tds.a$sampdate)
Now sampdate is a factor, and quant has the proper values:
str(tds.a)
'data.frame': 11434 obs. of 4 variables:
$ site : Factor w/ 143 levels "BC-0.5","BC-1",..: 134 127 134 134 73 73
$ sampdate: Factor w/ 890 levels "1981-11-30","1982-04-28",..: 686 268 727
$ param : Factor w/ 7 levels "Ca","Cl","Cond",..: 7 3 4 6 1 2 4 5 1 4 ...
$ quant : num 10800 280 1620 7580 79 114 301 27.5 381 274 ...
However, ...
dcast(tds.a, site + sampdate ~ param, value_var = 'quant')
c.tds.anal <- dcast(tds.a, site + sampdate ~ param, value_var = 'quant')
Aggregation function missing: defaulting to length.
That's because c.tds.anal has lost the quant values:
str(c.tds.anal)
'data.frame': 2309 obs. of 9 variables:
$ site : Factor w/ 143 levels "BC-0.5","BC-1",..: 1 1 1 2 2 2 2 2 2 2
...
$ sampdate: Factor w/ 890 levels "1981-11-30","1982-04-28",..: 239 252 260
99 101 102 155 163 170 179 ...
$ Ca : int 1 0 0 1 1 1 1 1 0 1 ...
$ Cl : int 1 0 0 1 1 1 1 1 0 1 ...
$ Cond : int 1 1 1 1 1 1 1 1 1 1 ...
$ Mg : int 1 0 0 1 1 1 1 1 0 1 ...
$ Na : int 0 0 0 1 1 1 1 1 0 1 ...
$ SO4 : int 1 1 1 1 1 1 1 1 0 1 ...
$ TDS : int 1 1 1 1 1 1 1 1 0 1 ...
I don't see what I did differently from your sample code.
Rich
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