On Jul 5, 2011, at 12:53 PM, Sam Steingold wrote:
Hi,
I am confused by the way the indexing works.
Actually I suspect you may be confused by how factors work. See below.
I read a table from a csv file like this:
ysmd <- read.csv("ysmd.csv",header=TRUE);
# And note that by default all character columns will become factors.
ysmd.table <- hash();
for (i in 1:length(ysmd$X.stock)) ysmd.table[ysmd$X.stock[i]] <-
ysmd[i,];
the first column ("X.stock") is a string (factor):
ysmd$X.stock[[100]]
[1] FLO
7757 Levels: A AA AA- AAAAA AAC AACC AACOU AACOW AADR AAI AAME AAN
AAON ... ZZZZT
when I print ysmd.table, I see the data I expect:
...
ZIOP : ZIOP 402600000 3.03 7.85 707694 6.3717
ZIP : ZIP 794900000 23.53 31.5 677046 23.2508
ZIPR : ZIPR 47100000 2.28 3.5 21865 2.4058
ZIV : ZIV -1 12.2987 17.3862 37455 16.6068
ZIXI : ZIXI 254900000 2.1 4.88 905849 3.5146
...
moreover,
ysmd.table[['FLO']]
X.stock market.cap X52.week.low X52.week.high
X3.month.average.daily.volume
100 FLO 2.984e+09 15.3133
22.37 1021580
X50.day.moving.average.price
100 21.3769
quite correctly.
however,
ysmd.table[ysmd$X.stock[[100]]]
<hash> containing 0 key-value pair(s).
NA : NULL
so, how do I access the hash table element using non-literal strings?
or, how do I convert ysmd$X.stock[[100]] to a string from whatever
it is
now?
Have you considered:
ysmd.table[ as.character( ysmd$X.stock[[100]]) ]
It appears that ysmd$X.stock[[100]] is a factor, and if so, you
probably want the character value that its numeric representation
points to. This is, of course, guesswork because you have not
disclosed what package `hash` comes from, so I do not have the benefit
of looking at its help page.
thanks!
--
Sam Steingold (http://sds.podval.org/) on CentOS release 5.6 (Final)
X 11.0.60900031
--
David Winsemius, MD
West Hartford, CT
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