On Jul 2, 2012, at 2:21 AM, Bert Gunter wrote:
Hi Kristina:
That's because I gave you the wrong function. It should be "with" not
"within", as:
sort2v4$adj_mean<-with(sort2v4, ave(mean, point, FUN=function(x)x-
x[1]))
within(dat,...) returns dat suitably modified.
with (dat,...) just returns the result of the function.
I frequently use within() when I mean with(), unfortunately. Sorry
for the
error.
That's interesting to me. I almost never use `within`. I'm wondering
if I'm missing something? As I read the help page `within` is going to
do something different when the expression is an assignment, so one
could do the following with `within`
within(dfrm, var2 <- var2/100)
... but that would have no lasting effect since its result was not
assigned, so I do not se an advantage over:
dfrm$var2 <- with(dfrm, var2/100)
In both case one would still need to assign the result to an object,
in the case of the first to 'dfrm' itself and in the second case to
dfrm[['var2']].
None of the examples on the help page use `within`. Is that because it
is inferior to transform?
-- Bert
On Sun, Jul 1, 2012 at 6:39 PM, Kristiina Hurme
<kristiina.hu...@uconn.edu>wrote:
Thanks everyone.
I tried them all, and got all to work except for the last one.
I tried
sort2v4$adj_mean<-within(sort2v4, ave(mean, point,
FUN=function(x)x-x[1]))
head(sort2v4)
point time mean sd adj_mean.point adj_mean.time
adj_mean.mean
adj_mean.sd
1 1 1 52.50100 1.5073927 1 1
52.50100
1.5073927
3 1 2 54.50182 0.8510329 1 2
54.50182
0.8510329
4 1 3 56.60174 1.5787222 1 3
56.60174
1.5787222
5 1 4 57.20000 1.2292726 1 4
57.20000
1.2292726
6 1 5 59.30000 2.2632327 1 5
59.30000
2.2632327
7 1 6 57.80089 1.4745218 1 6
57.80089
1.4745218
but am getting the columns in duplicate, rather than it performing
the
function. Any advice?
Thanks again,
Kristiina
--
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--
Bert Gunter
Genentech Nonclinical Biostatistics
Internal Contact Info:
Phone: 467-7374
Website:
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David Winsemius, MD
West Hartford, CT
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