search for: trdta

Displaying 3 results from an estimated 3 matches for "trdta".

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2009 Sep 02
4
Grouping data in a data frame: is there an efficient way to do it?
I have a data frame with about 10^6 rows; I want to group the data according to entries in one of the columns and do something with it. For instance, suppose I want to count up the number of elements in each group. I tried something like aggregate(my.df$my.field, list(my.df$my.field), length) but it seems to be very slow. Likewise, the split() function was slow (I killed it before it completed).
2009 Sep 04
1
Problem with locfit( ... , family="hazard")
I'm having difficulties with plot.locfit.3d, at least I think that is the problem. I have a large dataframe (about 4 MM cases) and was hoping to see a non-parametric estimate of the hazard plotted against two variables: > fit <- locfit(~surv.yr+ ur_protein + ur_creatinine, data=TRdta, cens = 1-death, family = "hazard", xlim=c(0,10)) # it took somewhere between 1 and 2 hours to complete, but it did complete and reported no errors or warnings. > plot(fit, pv=c("ur_protein", "ur_creatinine")) Error in if (from == to) rep.int(from, length.out)...
2010 Feb 25
5
Plotting 15 million points
Hi All I have a vector of about 15 million numbers which I would like to plot. The goal is the see the distribution. I tired the usual steps. 1. Histogram : never gets complete my window freezes w/out log base 10 2. Density : I first calculated the kernel density and then plotted it which worked. It would be nice to superimpose histogram with density but as of now I am not able to get this