<label:>RELATIONPLOT
variable <
censorvariable(values)> <=groupvariable>
</ options> ;
<label:>RELATIONPLOT
(variable1 variable2) <=groupvariable> </ options> ;
You use the RELATIONPLOT statement to create lifestress relation plots. A lifestress relation plot is a graphical tool for the analysis of data from accelerated life tests. The plot is a display of the relationship between life and stress, such as temperature or voltage. You can also use the RELATIONPLOT statement to display a probability plot alongside the relation plot. See Figure 16.9 for an example of a relation plot.
You can specify the keyword RPLOT as an alias for RELATIONPLOT. You can use any number of RELATIONPLOT statements after a PROC RELIABILITY statement. You can specify an optional label to distinguish between multiple RELATIONPLOT statements in the output.
See the section Analysis of Accelerated Life Test Data for an example that uses the RELATIONPLOT statement.
To create a lifestress relation plot, you must specify one variable. If your data are right censored, you must specify a censorvariable and, in parentheses, the values of the censorvariable that correspond to censored data values. You must specify one groupvariable to represent the values of stress. The groupvariable must be a numeric variable.
The RELATIONPLOT statement plots the uncensored values of your data given by variable versus the values of the groupvariable. You can optionally display a boxplot of the values of the data. You can also plot percentiles of the distribution fitted to the data. The RELATIONPLOT statement produces the same tabular output as the PROBPLOT statement, and all the analysis options are the same as for the PROBPLOT statement.
The elements of the RELATIONPLOT statement are described as follows.
Table 16.46: Analysis Options
Option 
Option Description 


CONFIDENCE=number 
Specifies the confidence coefficient for all confidence intervals. The number must be between 0 and 1. The default value is 0.95. 

CONVERGE=number 
Specifies the convergence criterion for maximum likelihood fit. See the section Maximum Likelihood Estimation for details. 

CONVH=number 
Specifies the convergence criterion for the relative Hessian convergence criterion. See the section Maximum Likelihood Estimation for details. 

CORRB 
Requests the parameter correlation matrix. 

COVB 
Requests the parameter covariance matrix. 

FITTYPE  FIT= fitspecification 
Specifies the method of estimating distribution parameters. The available fitspecifications and their meanings are shown in the following table. 



ITPRINT 
Requests the iteration history for the maximum likelihood fit. 

LRCL 
Requests likelihood ratio confidence intervals for distribution parameters. 

LRCLPER 
Requests likelihood ratio confidence intervals for distribution percentiles. 

LOCATION=number <LINIT> 
Specifies a fixed or initial value of the location parameter. 

MAXIT=number 
Specifies the maximum number of iterations allowed for a maximum likelihood fit. 

NOPCTILES 
Suppresses computation of percentiles. 

PCTLIST=numberlist 
Specifies a list of percentages for which to compute percentile estimates. The numberlist must be a list of numbers separated by blanks or commas. Each number in the list must be between 0 and 100. If this option is not specified, percentiles are computed for a standard list of percentages. 

PPOS=plottingposition 
Specifies the plottingposition type used to compute nonparametric estimates of the probability distribution function. See the section Probability Plotting for details. The plotting position types available are shown in the following table. 



PPOUT 
Requests a table of nonparametric cumulative probabilities in the printed output. 

PSTABLE=number 
Specifies a stable parameterization. The number must be between zero and one. See the section Stable Parameters for further information. 

RELATION=transformationkeyword 
Specifies the type of relationship between independent (stress) and dependent (lifetime) variables. The transformation specified is applied to the independent (stress) variable in the model. This determines the horizontal scale used in the relation plot. transformationkeyword can be any of the transformations listed in the following table. See Table 16.67 for definitions of the transformations. 



READOUT 
Specifies the data has the readout structure. 

SCALE=number <SCINIT> 
Specifies a fixed or initial value of scale parameter. 

SHAPE=number <SHINIT> 
Specifies a fixed or initial value of shape parameter. 

SINGULAR=number 
Specifies the singularity criterion for matrix inversion. 

SURVTIME=numberlist 
Requests that survival function be computed for values in numberlist. See the section Reliability Function for details. 

THRESHOLD=number 
Specifies a fixed threshold parameter. See Table 16.57 for the distributions with a threshold parameter. 

variable=numberlist 
Enables creation of plots of percentiles from a regression model when two independent variables are used in a MODEL statement effectlist. The FIT=REGRESSION option must be used with this option. Percentile plots are created for each value of the independent variable in the numberlist. numberlist is a list of numeric values separated by blanks or commas, or in the form of a list to <by >. 
Table 16.47 lists plot layout options that are available when you use traditional graphics.
Table 16.47: Plot Layout Options for Traditional Graphics
Option 
Option Description 


CENSYMBOL=symbol  (symbollist) 
Specifies symbols for censored values. The symbol is one of the symbol names (plus, star, square, diamond, triangle, hash, paw, point, dot, circle) or a letter (A–Z). If you are creating overlaid plots for groups of data, you can specify different symbols for the groups with a list of symbols or letters, separated by blanks, enclosed in parentheses. If no CENSYMBOL option is specified, the symbol used for censored values is the same as for failures. 

HOFFSET=value 
Specifies an offset for horizontal axis. 

INBORDER 
Requests a border around plots. 

LBOXES=number 
Specifies a line style for boxplots. 

LFIT=linetype  (linetypelist)) 
Specifies line styles for fit lines and confidence curves in a probability plot. The linetypelist is a list of numbers from 1 to 46 representing different linetypes; the numbers can be separated by blanks or commas or can be a list in the form to <by >. 

LPLOTFIT=linetype  (linetypelist)) 
Specifies line styles for percentile lines. linetypelist is a list of numbers that represent different linetypes; the numbers can be separated by blanks or commas or can be a list in the form to <by >. 

NOCENPLOT 
Suppresses plotting of censored data points. 

NOCONF 
Suppresses plotting of percentile confidence curves. 

NOFIT 
Suppresses plotting of fit line and percentile confidence curves. 

NOFRAME 
Suppresses the frame around the plotting area. 

NOPPLEGEND 
Suppresses the legend for overlaid probability plots. 

NOPPOS 
Suppresses plotting of symbols for failures in a probability plot. 

NORPLEGEND 
Suppresses the legend for the relation plot. 

PINTERVALS=intervaltype 
Specifies the type of parametric pointwise confidence interval displayed in a probability plot. The available types of intervals are listed in the following table. The default type is PROBABILITY, pointwise confidence intervals on cumulative failure probability. 



PLOTDATA <DATA  MEDIANS  BOXES> 
Requests that the data be plotted on the relationplot and specifies the representation of the data populations to be plotted. 

PLOTFIT <numberlist> 
Specifies that percentiles of the fitted distribution be plotted on the relation plot. The optional numberlist is a list of percentiles (between 0 and 100); if not specified, the 50th percentile (median) is plotted. 

PPLEGEND = legendstatementname 

 NONE 
Identifies a LEGENDn statement to specify legend for overlaid probability plots. 

PPLOT 
Places a probability plot on the same page as the relation plot. 

RCENSYMBOL=symbol  (symbollist) 
Specifies symbols that represent rightcensored and leftcensored observations in a relation plot. The symbol is one of the symbol names (plus, star, square, diamond, triangle, hash, paw, point, dot, circle) or a letter (A–Z). 

RPLEGEND = legendstatementname 

 NONE 
Identifies a LEGENDn statement to specify legend for the relation plot. 

SHOWMULTIPLES 
Displays the count for multiple overlaying symbols. 

TURNVLABELS 
Vertically strings out characters in labels for vertical axis. 

VOFFSET=value 
Specifies length of offset at upper end of vertical axis. 

WFIT=linetype 
Specifies line width for fit line and confidence curves. 
Table 16.48 lists plot layout options that are available when you use ODS graphics.
Table 16.48: Plot Layout Options for ODS Graphics
Option 
Option Description 


NOCENPLOT 
Suppresses plotting of censored data points. 

NOCONF 
Suppresses plotting of percentile confidence curves. 

NOFIT 
Suppresses plotting of fit line and percentile confidence curves. 

NOPPOS 
Suppresses plotting of symbols for failures in a probability plot. 

PINTERVALS=intervaltype 
Specifies the type of parametric pointwise confidence interval displayed in a probability plot. The available types of intervals are listed in the following table. The default type is PROBABILITY, pointwise confidence intervals on cumulative failure probability. 



PLOTDATA 
Requests that the data be plotted on the relationplot. 

PLOTFIT <numberlist> 
Specifies that percentiles of the fitted distribution be plotted on the relation plot. The optional numberlist is a list of percentiles (between 0 and 100); if not specified, the 50th percentile (median) is plotted. 

PPLOT 
Places a probability plot on the same page as the relation plot. 
Table 16.49 lists reference line options that are available when you use traditional graphics.
Table 16.49: Reference Line Options for Traditional Graphics
Option 
Option Description 


HREF <(INTERSECT)>=valuelist 
Requests reference lines perpendicular to 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. 

HREFLABELS=(’label1’ …’labeln’) 
Specifies labels for HREF= lines. 

HREFLABPOS=n 
Specifies the vertical position of labels for HREF= lines. The valid values for n and the corresponding label placements are shown in the following table:


LHREF=linetype 
Specifies a line style for HREF= lines. 

LSREF=linetype 
Specifies a line style for SREF= lines. 

LVREF=linetype 
Specifies a line style for VREF= lines. 

SREF=valuelist 
Specifies reference lines perpendicular to horizontal stress axis. 

SREFLABELS=(’label1’ …’labeln’) 
Specifies labels for SREF= lines 

SREFLABPOS=n 
Specifies horizontal position of labels for SREF= lines. The valid values for n and the corresponding label placements are shown in the following table:


VREF <(INTERSECT)>=valuelist 
Requests reference lines perpendicular to 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. 

VREFLABELS=(’label1’ …’labeln’) 
Specifies labels for VREF= lines. 

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:

Table 16.50 lists reference line options that are available when you use ODS graphics.
Table 16.50: Reference Line Options for ODS Graphics
Option 
Option Description 

PREF <(INTERSECT)>=valuelist 
Requests reference lines perpendicular to probability axis, if a probability plot is specified with the PPLOT option. 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. 
PREFLABELS=(’label1’ …’labeln’) 
Specifies labels for PREF= lines. 
SREF=valuelist 
Specifies reference lines perpendicular to horizontal stress axis. 
SREFLABELS=(’label1’ …’labeln’) 
Specifies labels for SREF= lines. 
LREF <(INTERSECT)>=valuelist 
Requests reference lines perpendicular to vertical (lifetime) 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. 
LREFLABELS=(’label1’ …’labeln’) 
Specifies labels for LREF= lines. 
Table 16.51 lists options that control the appearance of the text when you use traditional graphics. These options are not available if ODS Graphics is enabled.
Table 16.51: Text Enhancement Options
Option 
Option Description 

FONT=font 
Specifies a software font for text. 
HEIGHT=value 
Specifies the height of text used outside framed areas. 
INFONT=font 
Specifies a software font for text inside framed areas. 
INHEIGHT=value 
Specifies the height of text inside framed areas. 
Table 16.52 lists options that control the appearance of the axes when you use traditional graphics.
Table 16.52: Axis Options for Traditional Graphics
Option 
Option Description 

LAXIS=value1 TO value2<BY value3> 
Specifies tick mark values for the lifetime axis. value1, value2, and value3 must be numeric, and value1 must be less than value2. The lower tick mark is value1. Tick marks are drawn at increments of value3. The last tick mark is the greatest value that does not exceed value2. If value3 is omitted, a value of 1 is used. This method of specification of tick marks is not valid for logarithmic axes. Examples of LAXIS= lists are laxis = 1 to 10 laxis = 0 to 200 by 10 
LGRID=number 
Specifies a line style for all grid lines. The number is between 1 and 46 and specifies a linestyle for grids. 
LIFELOWER  LLOWER=number 
Specifies the lower limit on the lifetime axis scale. The LLOWER option specifies number as the lower lifetime axis tick mark. The tick interval and the upper lifetime axis limit are determined automatically. This option has no effect if the LAXIS option is used. 
LIFEUPPER  LUPPER=number 
Specifies the upper limit on the lifetime axis scale. The LUPPER option specifies number as the upper lifetime axis tick mark. The tick interval and the lower lifetime axis limit are determined automatically. This option has no effect if the LAXIS option is used. 
MPGRID 
Adds a minor grid for the probability axis. 
MINORLOGGRID 
Adds a minor grid for log axes. 
NOGRID 
Suppresses grid lines. 
NOLLABEL 
Suppresses the label for the lifetime axis. 
NOLTICK 
Suppresses tick marks and tick mark labels for lifetime or analysis variable axis. 
NOPLABEL 
Suppresses the label for the probability axis. 
NOPTICK 
Suppresses tick marks and tick mark labels for probability axis. 
NOSLABEL 
Suppresses the label for the stress axis. 
NOSTICK 
Suppresses tick marks and tick mark labels for stress axis. 
NSTRESSTICK=number 
Specifies the number of tick intervals for stress axis for relation plot. 
NTICK=number 
Specifies the number of tick intervals for the lifetime axis. This option has no effect if the LAXIS option is used. 
PCTLOWER  PLOWER=number 
Specifies the lower limit on the probability axis scale. 
PCTUPPER  PUPPER=number 
Specifies the upper limit on the probability axis scale. 
STRESSLOWER  SLOWER=number 
Specifies the lower limit on the stress axis scale. 
STRESSUPPER  SUPPER=number 
Specifies the upper limit on the stress axis scale. 
PAXISLABEL=‘string’ 
Specifies a label for the probability axis. 
WAXIS=n 
Specifies the line thickness for axes and frame. 
Table 16.53 lists options that control the appearance of the axes when you use ODS Graphics.
Table 16.53: Axis Options for ODS Graphics
Option 
Option Description 

LIFELOWER  LLOWER=number 
Specifies the lower limit on the lifetime axis scale. The LLOWER option specifies number as the lower lifetime axis tick mark. The tick interval and the upper lifetime axis limit are determined automatically. This option has no effect if the LAXIS option is used. 
LIFEUPPER  LUPPER=number 
Specifies the upper limit on the lifetime axis scale. The LUPPER option specifies number as the upper lifetime axis tick mark. The tick interval and the lower lifetime axis limit are determined automatically. This option has no effect if the LAXIS option is used. 
NOGRID 
Suppresses grid lines. 
PCTLOWER  PLOWER=number 
Specifies lower the limit on the probability axis scale. 
PCTUPPER  PUPPER=number 
Specifies upper the limit on the probability axis scale. 
STRESSLOWER  SLOWER=number 
Specifies the lower limit on the stress axis scale. 
STRESSUPPER  SUPPER=number 
Specifies the upper limit on the stress axis scale. 
PAXISLABEL=‘string’ 
Specifies a label for the probability axis. 
Table 16.54 lists options that control the use of a graphics catalog to store graphs if you use traditional graphics. These options are not available if ODS Graphics is enabled.
Table 16.54: Graphics Catalog Options
Option 
Option Description 

DESCRIPTION=‘string’ 
Description for graphics catalog member 
NAME=‘string’ 
Name for plot in graphics catalog 
Table 16.55 lists options that control colors and patterns used in the graph when you use traditional graphics. These options are not available if ODS Graphics is enabled.
Table 16.55: Color and Pattern Options
Option 
Option Description 

CAXIS=color 
Color for axis 
CBOXES=color 
Color for box frame for boxplots 
CBOXFILL=color 
Color for filling boxes for boxplots 
CCENSOR=color 
Color for filling censor plot area 
CENCOLOR=color 
Color for censor symbol 
CFIT=color  (colorlist) 
color for fit lines and confidence curves in a probability plot 
CFRAME=color 
Color for frame 
CGRID=color 
Color for grid lines 
CHREF=color 
Color for HREF= lines 
CPLOTFIT=color  (colorlist) 
colors for percentile lines 
CSREF=color 
Color for SREF= lines 
CTEXT=color 
Color for text 
CVREF=color 
Color for VREF= lines 
RCENCOLOR=color  (colorlist) 
Colors for the symbols representing uncensored, rightcensored, and leftcensored observations in a relation plot 