search for: zph

Hi, I''ve used old ZPH patch under squid 2.4 Stable4 and it works great ! Now I want to patch squid 2.4 stable 5, with new patch, on http://www.it-academy.bg/zph/ I''ve patched and installed squid 2.5 stable 5 succefully, but I can''t get ZPH works. I''m trying with ... $TC class add dev $LAN...

You report an error message: > plot(zph.revasFit[1]) Error in plot.window(xlim, ylim, log, asp, ...) : need finite 'ylim' values I have never seen this error before, and I cannot guess what causes it. You need to provide more information, and likely a small data set that produces the problem. Perhaps you have an x var...

Hello, I am hoping for some advice regarding warning/error messages I received when running a Cox regression # message 1 - obtained while creating a plot of residuals > plot (NV.zph, main = "groupNUSM - UNFIT", var= 'groupNUSM') Warning messages: 1: In approx(xx, xtime, seq(min(xx), max(xx), length.out = 17)[2 * : collapsing to unique 'x' values 2: In approx(xtime, xx, temp) : collapsing to unique 'x' values Ques 1- A plot is generated, i...

The following works, you need to include x=TRUE in the call to coxph. Passing the time and status variables as additional arguments is a matter of personal preference. f.coxph.zph<-function(x, timeVar, statusVar) { cox.fit <- coxph(Surv(timeVar, statusVar) ~ x, na.action = na.exclude, method = "breslow", x=TRUE) fit.zph<-cox.zph(cox.fit) fit.zph$table[,3] } time.cox <- ovarian$futime status.cox <- ovarian$fustat apply(ovarian[,-(1:2)],2, f.cox...

Hi, I wrote a function that worked well in R, but not in S-Plus, can anyone suggest a solution? > f.coxph.zph<-function(x) { cox.fit <- coxph(Surv(time.cox, status.cox) ~ x, na.action = na.exclude, method = "breslow") fit.zph<-cox.zph(cox.fit,transform='log') fit.zph$table[,3] } yyy is my data frame that contains survial time, censor status and predictor variables. > time...

Hello, I got error message when applying the plot function to the cox.zph object to create the Schoenfeld residual plots. > plot(zph.revasFit[1]) Error in plot.window(xlim, ylim, log, asp, ...) : need finite 'ylim' values In addition: Warning messages: 1: NaNs produced in: sqrt(x$var[i, i] * seval) 2: no non-missing arguments to min; returning In...

Hello, Excuse me for a more methodological than technical question. I'm developing a Cox model with 10 covariates. One of them is age (named "eta"). I've checked proportionality with cox.zph with age continuous: > cox.zph(coxph(Surv(TTP,CENSOTTP)~eta)) rho chisq p eta -0.0154 0.0225 0.88 and categorical (eta<60): > cox.zph(coxph(Surv(TTP,CENSOTTP)~eta<60)) rho chisq p eta < 60TRUE 0.0168 0.0255 0.8...

Hi, I am using the Survival package, more precisely the cox.zph function, to plot log(Hazard rate) over time. if I type plot(temp.zph[2]) then I get the plot I want. However, I want to change the label of the y axis that cox.zph prints. plot(temp.zph[2],xlab='Days', ylab='log hazard for Fast recovery cluster') then I get Error in plot....

Hi, I used to patch my squid with ZPH patch on http://www.it-academy.bg/zph/ > The idea behind this patch is to allow classification > of packets generated from the squid cache engine towards > clients. > The classification is based on whether the content is > being served from cache (a cache HIT), or > is bein...

Hi, I''m trying to share internet on a LAN I''ve a linux router with SQUID (with ZPH support) + FAIRNAT The idea is: - fairness sharing internet - priorize interactive traffic - if a web object is on squid-cache (HIT), user can download it, with a rate = LAN rate I''ve: - Last Fairnat Script: www.metamorpher.de/fairnat/ - SQUID 2.5STABLE5 with ZPH patch http://www.it-...

To enhance my understanding, and that of my students, I have a question about cox.zph in the survival package. If I have correctly gleaned the high-level point from the 1994 Biometrika paper of Grambsch and Therneau, it looks to me like cox.zph provides a mechanism to test for a simple trend in plots of a function of time, g(t) versus the scaled schoenfeld residuals and it also pro...

...ctor X and some don't [I'm not trying to be cagey about the setting here, it's just complicated to explain and I'm trying to keep my message short.] When I plot the survival curves, there's a qualitatively significant difference and this is confirmed by survdiff. When I run cox.zph, however, it's pretty clear that the proportional hazards assumption isn't satisfied: > zph <- cox.zph(cox) > zph rho chisq p Initially.Vulnerable -0.0476 32.5 1.19e-08 > Similarly, when I do plot(zph), B(t) is fairly non-constant. This isn...

Hi, I get a warning message when I plot cox.zph objects with the transform km and rank, but not with id and log with the same data set. Here's the command: example is a coxph object rk <- cox.zph(example, transform='rank') rk plot(rk) and here's the warning message: Warning messages: 1: suppression des ex-aequos de 'x&...

Dear R-users, I am sorry if this is obvious. I am testing the proportional hazard assumptions using cox.zph. If i am not wrong, a g(t) function must be assumed. Four possibilities available in R are "km","identity" and "rank". may i know what functions of time are these transformation assuming? Thanks a lot in advance for your wisdom. kind regards, sing yee ling [[alter...

Dear All, I am trying to apply the function 'cox.zph' of the library survival, but I receive this error message: not found the object 'residuals.coxph'. I have re-installed the library 'survival' without any change and also a search with RSiteSearch was unsuccessful.. Any suggestion? TIA Giovanni PS: R 2.2.0 Windows XP HE dr. Gi...

Dear all, I use the Andersen plot to check for proportional hazards assumption for a factor (say x) in the Cox regression model and obtained a straight line that pass through the origin. However, the formal test done by the R-function cox.zph, which is based on the plot of Schonefeld residuals against time, indicates that proportional hazards assumption is violated. Further, a plot of the score process (cumulative sums of schoenfeld residuals) against time again give the same conclusion as the cox.zph function and i am really stumped by...

Hi all, I was trying to test the assumption of proportional hazards assumption, I used the cox.zph function >cox.zph(coxfit6) Results are: rho chisq p x1 -0.0396 1.397 2.37e-01 x2 0.1107 9.715 1.83e-03 x3 -0.0885 7.743 5.39e-03 x4 0.0366 1.092 2.96e-01 x5 0.0242 0.455 5.00e-01 GLOBAL...

...tween covariables and time. A model such as "coxph(Surv(ptime, pstat) ~ age + age*ptime, ...." is invalid -- it is not at all what you think. If cph flags this as an error that is a good thing: I should probably add the same message to coxph. > Is is somewhat sensible to use cox.zph() to investigate which variables need time interaction... The cox.zph function is primarily graphical; I would respond to your question with "is it good to look at scatterplots before fitting a linear model?" My answer to this is emphatically yes. Terry Therneau

Dear All, Sorry to bother you again. I have a model: coxfita=coxph(Surv(rem.Remtime/365,rem.Rcens)~all.sex,data=nearma) and I'm trying to do a plot of Schoenfeld residuals using the code: plot(cox.zph(coxfita)) abline(h=0,lty=3) The error message I get is: Error in plot.window(...) : need finite 'ylim' values In addition: Warning messages: 1: In sqrt(x$var[i, i] * seval) : NaNs produced 2: In min(x) : no non-missing arguments to min; returning Inf 3: In max(x) : no non-missing arguments...

...nimal died. First question: given the way the parameters differ between the Gompertz distributions, the mortality rate will be higher for 'a' younger ages, higher for 'b' at older ages, and the assumption of the Cox Proportional Hazards model is violated a priori, isn't it? cox.zph confirms this. Yet I found plenty of Gompertz parameter values that differ, and lead to differences in survival times detectable by coxph, yet pass the cox.zph test. Should I assume that cox.zph is insufficiently sensitive and take measures to account for non-proportionality of hazards anytime I kn...