Plot Survival Curves
DESCRIPTION:
Plots a survival curve for each group. This function is deprecated, instead use survfit followed by plot.survfit.
USAGE: 
surv.plot(time, status, group=rep(1,length(time)), mark=3, col=1,
          lty=1, na.group = T, cex=1, log=F, yscale=1, xlab="",
          ylab="")
REQUIRED ARGUMENTS:
time:
vector of time values, all values must be greater than or equal to zero.
Missing values (NA) are allowed.
status:
vector of status values. Typically, the values are 0 or 1, in which case 0 means censored and 1 means uncensored (dead). The values can also be 1 and 2, in which case 1 is subtracted from all of the values. If the only value in status is 1, then this is interpreted as meaning that all values are uncensored.
Missing values (NA) are allowed. This must have the same length as time.
OPTIONAL ARGUMENTS:
group:
numeric vector or category defining subgroups, each group results in a curve.
mark:
vector of mark parameters. A mark is placed on the curve at each censored observation. The lines help file contains examples of the possible marks. For no marks, use " " (the space is significant). This must either be a single number or be a vector with length the number of groups.
col:
vector of colors. This must either be a single number or be a vector with length the number of groups.
lty:
vector of line types. This must either be a single number or be a vector with length the number of groups.
na.group:
if this is TRUE any observation with NA in group will form a group, if FALSE observations with NA in group will be omitted from the plot.
cex:
parameter available to change the size of the marks. Only the first element is used; all marks have the same size.
log:
logical value: should the y axis be on a log scale?
yscale:
a scalar to be used to multiply the y axis. A value of 100, for instance, would be used to get a percent scale.

In addition, the high-level graphics arguments described under par and the arguments to title may be supplied to this function.

VALUE:
a list with components x and y, containing the coordinates of the last point on each of the curves. This may be useful for labeling.
SIDE EFFECTS:
A plot with multiple survival curves is drawn, one curve for each unique value in group.
DETAILS:
The surv.fit function is used to estimate the curve for each group. If any of mark, col or lty have length 1, then it is replicated to have length the number of groups.
SEE ALSO:
surv.fit .
EXAMPLES: 
surv.plot(pgtime,pgstat,g2group,col=c(3,6),log=T)