search for: psmirnov2x

I'm working with some old code that worked under R 2.15.3 but gives an error under 3.0.0 and 3.0.1 : > 1.0 - .C("psmirnov2x", p = as.double(10.0), as.integer(1000), as.integer(1000))$p Error in .C("psmirnov2x", p = as.double(10), as.integer(1000), as.integer(1000)) : C symbol name "psmirnov2x" not in load table I don't understand why that function would not be in the 'load table'....

...mbinatorial argument (below), which I would like to see implemented in R. The p-value of the test is simply the probability that a random assignment of the pooled data to two sets of the sizes of the input data sets has a KS test statistic at least as great as that of the input data. The function psmirnov2x in ks.c calculates this probability by enumerating all such assignments as lattice walks, except that it doesn't know how to handle tied data points. The correct procedure can be deduced by considering that steps in such lattice walks represent steps along the x-axis in computing the empirical...

...FALSE) Two-sample Kolmogorov-Smirnov test data: x and y D = 0.6, p-value = 0.05465 alternative hypothesis: two.sided Agrees. Thus the algorithm for the exact null distribution of the two-sample K-S test statistic is erroneous. I. e., there is something wrong with the function "psmirnov2x" in ks.c. I don't yet know what the problem is. -- Charles Geyer Professor, School of Statistics University of Minnesota charlie@stat.umn.edu -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/...

This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --1132542651-1468968864-1260896436=:8788 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII I am using R version 2.6.2 (2008-02-08) on a Ubuntu Linux system. I seemed to be finding occasional errors in the p-values produced by ks.test(a,b)

...(x,y) >>> >>> The value of the D_2,5 statistic is calculated as 0.4 correctly, but the >>> p-value is stated by R as 1, though in fact it should be 20/21=0.9524 >> >> >> What we seem to have here is a rounding error problem. >> >> In ks.c:psmirnov2x, there is a double loop including >> if(fabs(i / md - j / nd) > q) >> u[j] = 0; >> >> where md=2, nd=5, and q=3/10. >> >> Now, to full precision abs(1/2 - 4/5) > 3/10 is false, but at least on my >> MacBook it is true in C double precisio...

...; y<-c(2.5,4.5) >> ks.test(x,y) >> >> The value of the D_2,5 statistic is calculated as 0.4 correctly, but the >> p-value is stated by R as 1, though in fact it should be 20/21=0.9524 > > > What we seem to have here is a rounding error problem. > > In ks.c:psmirnov2x, there is a double loop including > if(fabs(i / md - j / nd) > q) > u[j] = 0; > > where md=2, nd=5, and q=3/10. > > Now, to full precision abs(1/2 - 4/5) > 3/10 is false, but at least on my > MacBook it is true in C double precision. > > I'm not sure...

...>> The value of the D_2,5 statistic is calculated as 0.4 correctly, but the >>>> p-value is stated by R as 1, though in fact it should be 20/21=0.9524 >>> >>> >>> What we seem to have here is a rounding error problem. >>> >>> In ks.c:psmirnov2x, there is a double loop including >>> if(fabs(i / md - j / nd) > q) >>> u[j] = 0; >>> >>> where md=2, nd=5, and q=3/10. >>> >>> Now, to full precision abs(1/2 - 4/5) > 3/10 is false, but at least on >>> my MacBook it...

Dear all, I calculate the test statistic for the KS test outside R, and wish to use R only to calculate the corresponding p-value. Is there a way for doing this? (as far as I see, ks.test() requires raw data as input). Alternatively, is there a way to provide the ks.test() the two CDFs (two samples test) rather than the (x, y) data vectors? Thanks in advance, Rani