PROBPLOT Statement
- PROBPLOT | PPLOT < / options > ;
You can use the PROBPLOT statement to create a probability plot from lifetime
data. The data can be uncensored, right-censored, or arbitrarily censored.
You can specify any number of PROBPLOT statements after a MODEL statement. The
syntax used for the response in the MODEL statement determines the type of censoring
assumed in creating the probability plot. The model fit with the MODEL statement
is plotted along with the data. If there are covariates in the model, they are set to
constant values specified in the XDATA= data set when creating the probability plot.
If no XDATA= data set is specified, continuous variables are set to their overall
mean values and categorical variables specified in the CLASS statement are set
to their highest levels.
You can specify the following options to control the content, layout, and
appearance of a probability plot.
- ANNOTATE=SAS-data-set
- ANNO=SAS-data-set
-
specifies an ANNOTATE data set, as described
in SAS/GRAPH Software: Reference, that enables
you to add features to the probability plot. The ANNOTATE=
data set you specify in the PROBPLOT statement is used
for all plots created by the statement.
- CAXIS=color
- CAXES=color
-
specifies the color used for the axes and tick marks.
This option overrides any COLOR= specifications in an AXIS
statement. The default is the first color in the device color list.
- CCENSOE=color
-
specifies the color for filling the censor plot area.
The default is the first color in the device color list.
- CENBIN
-
plots censored data as frequency counts (rounding-off for non-integer
frequency) rather than as individual points.
- CENCOLOR=color
-
specifies the color for the censor symbol.
The default is the first color in the device color list.
- CENSYMBOL=symbol | (symbol list)
-
specifies symbols for censored values.
The symbol is one of the symbol names (plus, star, square, diamond,
triangle, hash, paw, point, dot, and circle)
or a letter (A -Z).
If you do not specify the CENSYMBOL= option, the symbol used for censored
values is the same as for failures.
- CFIT=color
-
specifies the color for the fitted probability line and confidence curves.
The default is the first color in the device color list.
- CFRAME=color
- CFR=color
-
specifies the color for the area enclosed by the axes
and frame. This area is not shaded by default.
- CGRID=color
-
specifies the color for grid lines.
The default is the first color in the device color list.
- CHREF=color
- CH=color
-
specifies the color for lines requested by the HREF= option.
The default is the first color in the device color list.
- CTEXT=color
-
specifies the color for tick mark values and axis labels. The
default is the color specified for the CTEXT= option in the
most recent GOPTIONS statement.
- CVREF=color
- CV=color
-
specifies the color for lines requested by the VREF= option.
The default is the first color in the device color list.
- DESCRIPTION='string'
- DES='string'
-
specifies a description, up to 40 characters,
that appears in the PROC GREPLAY master menu.
The default is the variable name.
- FONT=font
-
specifies a software font for reference line and axis labels.
You can also specify fonts for axis labels in an AXIS statement.
The FONT= font takes precedence over the FTEXT=
font specified in the most
recent GOPTIONS statement.
Hardware characters are used by
default.
- HCL
-
computes and draws confidence limits for the predicted probabilities
in the horizontal direction.
- HEIGHT=value
-
specifies the height of text used outside framed areas.
The default value is 3.846 (in percentage).
- HLOWER=value
-
specifies the lower limit on the lifetime axis scale.
The HLOWER= option specifies
value as the lower lifetime axis tick mark. The tick
mark interval and the upper axis limit are determined automatically.
- HOFFSET=value
-
specifies the offset for the horizontal axis.
The default value is 1.
- HUPPER=value
-
specifies
value as the upper lifetime axis tick mark. The tick
mark interval and the lower axis limit are determined automatically.
- HREF < (INTERSECT) > =value-list
-
requests reference lines perpendicular to the
horizontal axis. If (INTERSECT) is specified, a second reference
line perpendicular to the vertical axis is drawn that intersects
the fit line at the same point as the horizontal axis reference line.
If a horizontal axis reference line label is specified,
the intersecting vertical axis reference line
is labeled with the vertical axis value.
See also the CHREF=, HREFLABELS=, and LHREF= options.
- HREFLABELS='label1' ... 'labeln'
- HREFLABEL='label1' ... 'labeln'
- HREFLAB='label1' ... 'labeln'
-
specifies labels for the lines requested by the HREF= option.
The number of labels must equal the number of lines.
Enclose each label in quotes. Labels can be up to 16
characters.
- HREFLABPOS=n
-
specifies the vertical position of labels for HREF= lines.
The following table shows the valid values for n and
the corresponding label placements.
|
n
|
label placement
|
| 1 | top |
| 2 | staggered from top |
| 3 | bottom |
| 4 | staggered from bottom |
| 5 | alternating from top |
| 6 | alternating from bottom |
- INBORDER
-
requests a border around probability plots.
- INTERTILE=value
-
specifies the distance between tiles.
- ITPRINTEM
-
displays the iteration history for the Turnbull algorithm.
- JITTER=value
-
specifies the amount to jitter overlaying plot symbols,
in units of symbol width.
- LFIT=linetype
-
specifies a line style for fitted curves and confidence limits.
By default, fitted curves are drawn by connecting solid lines
(linetype = 1), and confidence limits are drawn by connecting
dashed lines (linetype = 3).
- LGRID=linetype
-
specifies a line style for all grid lines.
linetype is between 1 and 46. The default is 35.
- LHREF=linetype
- LH=linetype
-
specifies the line type for lines requested by
the HREF= option. The default is 2, which produces a
dashed line.
- LVREF=linetype
- LV=linetype
-
specifies the line type for lines requested by
the VREF= option. The default is 2, which produces a dashed line.
- MAXITEM=n1 <,n2> n1
-
specifies the maximum number of iterations allowed for the
Turnbull algorithm. Iteration history will be printed
in increments of n2 if requested with the ITPRINTEM
option. See the section "Arbitrarily Censored Data" for details.
- NAME='string'
-
specifies a name for the plot, up to eight characters,
that appears in the PROC GREPLAY master
menu. The default is 'LIFEREG'.
- NOCENPLOT
-
suppresses the plotting of censored data points.
- NOCONF
-
suppresses the default percentile confidence bands on the
probability plot.
- NODATA
-
suppresses plotting of the estimated empirical probability plot.
- NOFIT
-
suppresses the fitted probability (percentile) line and confidence bands.
- NOFRAME
-
suppresses the frame around plotting areas.
- NOGRID
-
suppresses grid lines.
- NOHLABEL
-
suppresses horizontal labels.
- NOHTICK
-
suppresses horizontal tick marks.
- NOPOLISH
-
suppresses setting small interval probabilities to zero
in the Turnbull algorithm.
- NOVLABEL
-
suppresses vertical labels.
- NOVTICK
-
suppresses vertical tick marks.
- NPINTERVALS=interval type
-
specifies one of the
two kinds of confidence limits for the estimated cumulative probabilities,
pointwise (NPINTERVALS=POINT) or simultaneous (NPINTERVALS=SIMUL),
requested by the PPOUT option to be printed in the tabular output.
- PCTLIST=value-list
-
specifies the list of percentages for which
to compute percentile estimates. value-list must be
a list of values separated by blanks or commas. Each
value in the list must be between 0 and 100.
- PLOWER=value
-
specifies the lower limit on the probability axis scale.
The PLOWER= option specifies
value as the lower probability axis tick mark. The tick
mark interval and the upper axis limit are determined automatically.
- PRINTPROBS
-
prints intervals and associated probabilities for the Turnbull algorithm.
- PUPPER=value
-
specifies the upper limit on the probability axis scale.
The PUPPER= option specifies
value as the upper probability axis tick mark. The tick
mark interval and the lower axis limit are determined automatically.
- PPOS=character-list
-
specifies the plotting position type. See the section "Probability Plotting" for details.
|
PPOS
|
Method
|
| EXPRANK | expected ranks |
| MEDRANK | median ranks |
| MEDRANK1 | median ranks (exact formula) |
| KM | Kaplan-Meier |
| MKM | modified Kaplan-Meier (default) |
- PPOUT
-
specifies that a table of the cumulative
probabilities plotted on the probability plot be printed.
Kaplan-Meier estimates of the cumulative probabilities are also printed,
along with standard errors and confidence limits. The confidence limits can be
pointwise or simultaneous, as specified by the NPINTERVALS= option.
- PROBLIST=value-list
-
specifies the list of initial values for
the Turnbull algorithm.
- ROTATE
-
requests probability plots with probability scale on
the horizontal axis.
- SQUARE
-
makes the layout of the probability plots square.
- TOLLIKE=value
-
specifies the criterion for convergence in the Turnbull
algorithm.
- TOLPROB=value
-
specifies the criterion for setting the interval probability
to zero in the Turnbull algorithm.
- VAXISLABEL=`string'
-
specifies a label for the vertical axis.
- VREF=value-list
-
requests reference lines perpendicular to the
vertical axis. If (INTERSECT) is specified,
a second reference line perpendicular
to the horizontal axis is drawn that intersects the
fit line at the same point as the vertical axis reference line.
If a vertical axis reference line label is specified,
the intersecting horizontal axis reference line
is labeled with the horizontal axis value.
See also the entries for the CVREF=, LVREF=, and VREFLABELS= options.
- VREFLABELS='label1' ... 'labeln'
- VREFLABEL='label1' ... 'labeln'
- VREFLAB='label1' ... 'labeln'
-
specifies labels for the lines requested by the VREF=
option. The number of labels must equal the number of
lines. Enclose each label in quotes. Labels can be up
to 16 characters.
- VREFLABPOS=n
-
specifies the horizontal position of labels for VREF= lines.
The valid values for n and the corresponding label placements are
shown in the following table.
|
n
|
label placement
|
| 1 | left |
| 2 | right |
- WAXIS=n
-
specifies line thickness for axes and frame. The default value is 1.
- WFIT=n
-
specifies line thickness for fitted curves. The default value is 1.
- WGRID=n
-
specifies line thickness for grids. The default value is 1.
- WREFL=n
-
specifies line thickness for reference lines. The default value is 1.
Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
