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⇤ ← Revision 1 as of 2008-11-24 16:45:40
Size: 888
Comment:
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Size: 1413
Comment:
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| Deletions are marked like this. | Additions are marked like this. |
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| ||||<33% style="TEXT-ALIGN: center"> Score || Specificity || 1- Sensitivity || ||||<33% style="VERTICAL-ALIGN: top; TEXT-ALIGN: center"> 2000 || 0.48 || 0.02 || ||||<33% style="VERTICAL-ALIGN: top; TEXT-ALIGN: center"> 1000 || 0.56 || 0.035 || ||||<33% style="VERTICAL-ALIGN: top; TEXT-ALIGN: center"> 400 || 0.59 || 0.06 || ||||<33% style="VERTICAL-ALIGN: top; TEXT-ALIGN: center"> 200 || 0.74 || 0.16 || ||||<33% style="VERTICAL-ALIGN: top; TEXT-ALIGN: center"> 100 || 0.85 || 0.30 || |
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| /time1 to time5 x1 to x5. | /time1 to time6 x1 to x6. |
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| 0 0.56 0.78 0.91 1 0 0.01 0.19 0.58 1 | 0 0.48 0.56 0.59 0.74 0.85 1.00 0 0.02 0.036 0.06 0.10 0.30 1.00 |
Using SPSS to compute the area under a ROC curve
Score |
Specificity |
1- Sensitivity |
|
2000 |
0.48 |
0.02 |
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1000 |
0.56 |
0.035 |
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400 |
0.59 |
0.06 |
|
200 |
0.74 |
0.16 |
|
100 |
0.85 |
0.30 |
|
DATA LIST free
/time1 to time6 x1 to x6.
BEGIN DATA.
0 0.48 0.56 0.59 0.74 0.85 1.00 0 0.02 0.036 0.06 0.10 0.30 1.00
END DATA.
define !trap( !pos !tokens(1)
/!pos !tokens(1)
/!pos !cmdend).
matrix.
get m /variables=!3.
compute area=make(!1,1,0).
loop ib=1 to !1.
+ compute f=0.
+ loop ic= 1 to !2-1.
+ compute id=ic+!2.
+ compute g=make(1,1,m(ib,id)).
+ compute h=make(1,1,m(ib,id+1)).
+ compute i=g > h.
+ compute j=i*(g-h)+(1-i)*(h-g).
+ compute a=make(1,1,m(ib,ic)).
+ compute b=make(1,1,m(ib,ic+1)).
+ compute c=a > b.
+ compute d=c*b+(1-c)*a.
+ compute e=0.5*c*(a-b)+0.5*(1-c)*(b-a).
+ compute f=f+((d+e))*j.
+ end loop.
+ compute area(ib)=f.
end loop.
save {m, area} /outfile=* /variables=!3, area.
print area.
end matrix.
!end define.
!trap 1 5 time1 to time5 x1 to x5.