hi, i've posted this question before but it somehow disappeared after i edited it. i want to change the statistic in the ROC curve plot of proc logistic: data have;
input pred resp;
datalines;
0 1
1 1
2 0
3 1
4 1
5 1
6 1
7 0
8 0
9 1
;
ods graphics on;
ods select roccurve;
ods noproctitle;
proc logistic;
model resp = pred / nofit;
roc "have" pred = pred;
run;
ods graphics off; instead of the c statistic (AUC, AUROC), i want to display Somers' d statistic (Gini coefficient, AR). both statistics are related by: d = 2*c-1. i use proc template with the source statement to get the following code, where i've changed only a single line (see comment on the right side): proc template;
define statgraph Stat.Logistic.Graphics.Roc;
notes "Receiver Operating Characteristic Curve";
dynamic _cValue _TITLE _ROCID _ROCIDNOTE _byline_ _bytitle_ _byfootnote_;
mvar _ROC_YAXISOPTS_LABEL _ROC_XAXISOPTS_LABEL _ROC_ENTRYTITLE _ROC_ENTRYTITLE2 _ROC_ENTRY_ID;
BeginGraph / designwidth=defaultDesignHeight;
if (EXISTS(_ROC_ENTRYTITLE))
entrytitle _ROC_ENTRYTITLE;
else
entrytitle _TITLE;
endif;
if (EXISTS(_ROC_ENTRYTITLE2))
entrytitle _ROC_ENTRYTITLE2 / textattrs=GRAPHVALUETEXT;
else
entrytitle "Gini coefficient = " eval (STRIP(PUT(2*_CVALUE-1,6.4))) / textattrs=GRAPHVALUETEXT; /* i've changed only this line */
endif;
layout overlayequated / equatetype=square yaxisopts=(gridDisplay=auto_on label=_ROC_YAXISOPTS_LABEL shortlabel="TPF"
offsetmin=0.05 offsetmax=0.05) xaxisopts=(gridDisplay=auto_on label=_ROC_XAXISOPTS_LABEL shortlabel="FPF" offsetmin=0.05
offsetmax=0.05) commonaxisopts=(tickvaluelist=(0 .25 .5 .75 1) viewmin=0 viewmax=1);
lineparm x=0 y=0 slope=1 / clip=true extend=true lineattrs=GRAPHREFERENCE;
seriesplot y=_SENSIT_ x=_1MSPEC_ / primary=true rolename=(tip1=_ROC_ tip2=_FREQ_ tip3=_WEIGHT_ tip4=_POSPRED_ tip5=
_NEGPRED_ tip6=_PROB_) tip=(tip1 y x tip2 tip3 tip4 tip5 tip6);
if (EXISTS(_ROCID))
scatterplot y=_SENSIT_ x=_1MSPEC_ / rolename=(tip1=_ROC_ tip2=_FREQ_ tip3=_WEIGHT_ tip4=_POSPRED_ tip5=_NEGPRED_ tip6=
_PROB_ tip7=_ROCID) tip=(tip1 tip7 y x tip2 tip3 tip4 tip5 tip6) freq=eval (1-MISSING(_ROCID));
endif;
seriesplot y=_SENSIT_ x=_1MSPEC_ / datalabel=_ROCID datalabelattrs=GRAPHDATADEFAULT lineattrs=GRAPHDATADEFAULT (thickness=
0) markerattrs=GRAPHDATADEFAULT (size=0) rolename=(tip1=_ROC_ tip2=_FREQ_ tip3=_WEIGHT_ tip4=_POSPRED_ tip5=_NEGPRED_
tip6=_PROB_) tip=(tip1 y x tip2 tip3 tip4 tip5 tip6);
if (EXISTS(_ROC_ENTRY_ID))
entry halign=right textattrs=GRAPHDATATEXT _ROC_ENTRY_ID / location=inside editable=true valign=bottom;
else
entry halign=right textattrs=GRAPHDATATEXT _ROCIDNOTE / location=inside editable=true valign=bottom;
endif;
endlayout;
if (_BYTITLE_)
entrytitle _BYLINE_ / textattrs=GRAPHVALUETEXT;
else
if (_BYFOOTNOTE_)
entryfootnote halign=left _BYLINE_;
endif;
endif;
EndGraph;
end;
run; rerunning proc logistic gives what i want. for two predictors, i want to do the same: data have;
input pred1 pred2 resp;
datalines;
0 0 1
2 1 1
2 2 0
4 3 1
2 4 1
5 5 1
7 6 1
9 7 0
9 8 0
7 9 1
;
ods graphics on;
ods select rocoverlay;
ods noproctitle;
proc logistic;
model resp = pred1 pred2 / nofit;
roc "pred1" pred = pred1;
roc "pred2" pred = pred2;
roccontrast reference("pred1");
run;
ods graphics off; proc template;
define statgraph Stat.Logistic.Graphics.ROCOverlay;
notes "Receiver Operating Characteristic Overlaid Curves";
dynamic _TITLE _byline_ _bytitle_ _byfootnote_;
mvar _ROC_YAXISOPTS_LABEL _ROC_XAXISOPTS_LABEL _ROCOVERLAY_ENTRYTITLE;
BeginGraph / designwidth=defaultDesignHeight;
if (EXISTS(_ROCOVERLAY_ENTRYTITLE))
entrytitle _ROCOVERLAY_ENTRYTITLE;
else
entrytitle _TITLE;
endif;
layout overlayequated / equatetype=square yaxisopts=(gridDisplay=auto_on label=_ROC_YAXISOPTS_LABEL shortlabel="TPF"
offsetmin=0.05 offsetmax=0.05) xaxisopts=(gridDisplay=auto_on label=_ROC_XAXISOPTS_LABEL shortlabel="FPF" offsetmin=0.05
offsetmax=0.05) commonaxisopts=(tickvaluelist=(0 .25 .5 .75 1) viewmin=0 viewmax=1);
lineparm x=0 y=0 slope=1 / clip=true extend=true lineattrs=GRAPHREFERENCE;
seriesplot y=_SENSIT_ x=_1MSPEC_ / tip=(group y x) group=_ROC_ index=_GROUP_ name="Step" primary=true;
discretelegend "Step" / title="Gini coefficient"; /* i've changed only this line */
endlayout;
if (_BYTITLE_)
entrytitle _BYLINE_ / textattrs=GRAPHVALUETEXT;
else
if (_BYFOOTNOTE_)
entryfootnote halign=left _BYLINE_;
endif;
endif;
EndGraph;
end;
run; here, i can only change the title of the legend - but i don't know from where the c statistic in parentheses comes? is it possible to change that, too? any help is much appreciated.
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