_P_l_o_t _m_e_t_h_o_d _f_o_r _s_u_r_v_f_i_t.
	
	     plot.survfit(survfit, conf.int=<<see below>>, mark.time=T,
	      mark=3, col=1, lty=1, lwd=1, cex=1, log=F, yscale=1, xscale=1, xlab="",
	      ylab="", xaxs='i', ...)
	
	_A_r_g_u_m_e_n_t_s:
	
	      survfit:
	     structure returned by survfit.
	
	     conf.int:
	     determines whether confidence intervals will be plot-
	     ted.  The default is to do so if there is only 1 curve,
	     i.e., no strata.
	
	    mark.time:
	     controls the labeling of the curves.  If set to False,
	     no labeling is done.  If True, then curves are marked
	     at each censoring time.  If mark.time is a numeric vec-
	     tor, then curves are marked at the specified time
	     points.
	
	         mark:
	     vector of mark parameters, which will be used to label
	     the curves.  The lines help file contains examples of
	     the possible marks.  The vector is reused cyclically if
	     it is shorter than the number of curves.
	
	          col:
	     vector of colors.  The default value is 1.
	
	          lty:
	     vector of line types. The default value is 1.
	
	          lwd:
	     vector of line widths. The default value is 1.
	
	          cex:
	     parameter available to change the size of "mark".  Not
	     a vector; all marks have the same size.
	
	          log:
	     logical value: should the y axis be on a log scale?
	
	       yscale:
	     will be used to multiply the labels on the y axis.  A
	     value of 100, for instance, would be used to give a
	     percent scale.  Only the labels are changed, not the
	     actual plot coordinates, so that adding a curve with
	     "lines(surv.exp(...))", say, will perform as it did
	     without the yscale arg.
	
	       xscale:
	     will be used in a similar manner for labels on the x
	     axis.  A value of 365.25 will give labels in years
	     instead of the original days.
	
	         xlab:
	     label given to the x-axis.
	
	         ylab:
	     label given to the y-axis.
	
	         xaxs:
	     the x axis style, as listed in par.  The S default
	     option of "r" leads to curves that are "too far" from
	     the y axis.  This is, of course, just a matter of
	     esthetic opinion.
	
	     Value:
	
	     a list with components x and y, containing the coordi-
	     nates of the last point on each of the curves.  This
	     may be useful for labeling.
	
	     A plot of survival curves is produced, one curve for
	     each strata.
	
	_E_x_a_m_p_l_e_s:
	
	     plot.survfit(survfit(Surv(pgtime,pgstat) ~g2group),col=c(3,6),log=T)