> I've been tweaking some lines, from a thread a few weeks ago, trying to
> get a decent kaplan-meier curve with numbers at risk printed below the
> x-axis.

> Two things I'd welcome suggestions on (1) lining up the numbers at risk
> with the time points on the k-m curve - it doesn't look to bad on the
> screen, but doesn't look right when saved as a pdf and (2) there's a
> white box around the legend which I can't seem to figure out how to
> remove - unless there are other suggestions to prettify the legend.

> I'm trying to generalise as much as possible and minimise on data
> dependent tweaking so that the code would be useable with minimal
> changes for different datasets.

> Thanks

> Gary

> The code to reproduce the figure is

> library(ggplot2)
> require(survival)

> fit <- survfit(Surv(time, status) ~ rx, data = colon)

> df <- data.frame(
>   time    = fit$time,
>   n.risk  = fit$n.risk,
>   n.event = fit$n.event,
>   surv    = fit$surv,
>   strata  = gsub("rx=", "", summary(fit, censored = T)$strata),
>   upper   = fit$upper,
>   lower   = fit$lower
> )

> zeros <- data.frame(time = 0, surv = 1, strata = gsub("rx=", "",
> levels(summary(fit)$strata)), upper = 1, lower = 1)

> df <- rbind.fill(zeros, df)

> p <- ggplot(df, aes(time, surv, colour = strata)) +
>        geom_step(size = 0.6) +
>        xlim(0, max(fit$time)) +
>        ylim(0, 1) +
>        xlab("days from randomization") +
>        ylab("survival probability") +
>        scale_colour_brewer(name = "Treatment", pal = "Set1") +
>        opts(legend.position = c(0.9, 0.9)) +
>        opts(legend.key = theme_rect(colour = NA))

> times <- seq(0, max(fit$time), by = 500)

> risk.data <- data.frame(strata = summary(fit, times = times, extend =
> T)$strata,
>     time = summary(fit, times = times, extend = T)$time,
>     n.risk = summary(fit, times = times, extend = T)$n.risk)

> data_table <- ggplot(risk.data, aes(x = time, y = strata, label =
> format(n.risk, nsmall = 0)), colour = strata) +
>     geom_text(size = 3.5) +
>     theme_bw() +
>     scale_y_discrete(formatter = abbreviate, limits = c("rx=Obs",
> "rx=Lev", "rx=Lev+5FU"), labels = c("Obs", "Lev", "Lev+5FU")) +
>     opts(panel.grid.major = theme_blank()) +
>     opts(panel.grid.minor = theme_blank()) +
>     opts(panel.border     = theme_blank()) +
>     opts(axis.text.x      = theme_blank()) +
>     opts(axis.ticks       = theme_blank()) +
>     xlim(0, max(fit$time))

> data_table <- data_table + opts(legend.position = "none") + xlab(NULL) +
> ylab(NULL)

> data_table <- data_table + opts(plot.margin = unit(c(-0.5, 0, 0, -0.75),
> "lines"))

> # + opts(plot.margin = unit(c(-0.5, 1, 0, 0.5), "lines")) + xlab(NULL) +
> ylab(NULL)

> Layout <- grid.layout(nrow = 2, ncol = 1,heights = unit (c(2, .25),
> c("null", "null")))

> vplayout <- function (...) {
>     grid.newpage()
>     pushViewport(viewport(layout = Layout))
> }

> subplot <- function(x, y) viewport(layout.pos.row = x, layout.pos.col = y)
> mmplot <- function(a, b) {
>     vplayout()
>     print(a, vp = subplot(1, 1))
>     print(b, vp = subplot(2, 1))
> }

> #pdf("c:\\test.pdf", pointsize=11, paper="a4r", width=10, height=10)
> mmplot(p, data_table)
> #dev.off()

> ---------------------------------------------------------------
> Dr Gary S Collins                       Tel: +44 (0)1865 284418
> Centre for Statistics in Medicine       Fax: +44 (0)1865 284424
> Wolfson College Annexe                    www.csm-oxford.org.uk
> University of Oxford
> Linton Road
> Oxford, OX2 6UD
> ---------------------------------------------------------------