* Macro call .
*   Usage contour x1 x2 x3 x4 to xp .
*  Go to 1) and  the Click Run and Then Run to End.
*Read in your data set.
* .
*http://stat.tamu.edu/~mspeed/spss/general.html and look under Regression for Countour1 tutotial .
*use the line below with your varaible names   highlite the line and then hit the Play botton > above.


 CONTOUR testing voltg .


*1).

define contour (!POS !CMDEND).

SAVE OUTFILE='temp_cont.sav'
  /COMPRESSED.



 !do !i !in (!1).
!do !j !in (!1).

!if (!i = !j)  !then .
!break.
!ifend.          
                

matrix.
get x /variables=!i  !j / file ='temp_cont.sav' /Missing=Omit.
 * print x.
compute nc =ncol(x).
compute nr = nrow(x).
* print nc.
* print nr.
compute j = make(nr,1,1).
* print j.
compute means = t(j)*x/nr.
 print means.
compute a1 =  kroneker(means,j).
* print a1.
compute a2 = x-a1.
compute a3 = t(a2)*a2/(nr ).
* print a3.
compute eval1=make(nc,1,0).
* print eval1.
compute evect1 =make(nc,nc,0).
* print evect1.
call eigen(a3,evect1,eval1).
* print eval1.
* print evect1.
* alpha = .05.

* npts = number of points on contour.
compute npts =300 .
* print c.
* print npts.
compute t1 =({1:npts-1}-{1})*artan(1)*8/(npts-1).
 * print t1.
compute c =-2*ln(.05).
compute a = sqrt(c*eval1(1,1)).
compute b = sqrt(c*eval1(2,1)).
print a.
print b.
compute s1 = (sin(t1)) *a.
compute s2 = (cos(t1))*b.
compute s3={t(s1),t(s2)}.
compute j = make(npts,1,1).
* print j.
compute nrows3 =nrow(s3).
compute ncols3 = ncol(s3).
* print nrows3.
 *print ncols3.
compute a1 =  kroneker(means,j).
* print a1.
compute s4 = s3*t(evect1) +a1.
compute c =-2*ln(.1).
compute a = sqrt(c*eval1(1,1)).
compute b = sqrt(c*eval1(2,1)).
* print a.
* print b.
compute s1 = (sin(t1)) *a.
compute s2 = (cos(t1))*b.
compute s3={t(s1),t(s2)}.
compute j = make(npts,1,1).
* print j.
compute nrows3 =nrow(s3).
compute ncols3 = ncol(s3).
* print nrows3.
 *print ncols3.
compute a1 =  kroneker(means,j).
* print a1.
compute s4 = {s3*t(evect1) +a1,s4}.
compute c =-2*ln(.5).
compute a = sqrt(c*eval1(1,1)).
compute b = sqrt(c*eval1(2,1)).
* print a.
* print b.
compute s1 = (sin(t1)) *a.
compute s2 = (cos(t1))*b.
compute s3={t(s1),t(s2)}.
compute j = make(npts,1,1).
* print j.
compute nrows3 =nrow(s3).
compute ncols3 = ncol(s3).
* print nrows3.
 *print ncols3.
compute a1 =  kroneker(means,j).
* print a1.
compute s4 = {s3*t(evect1) +a1,s4}.
save s4 /outfile=*.
end matrix.
MATCH FILES /FILE=*
 /FILE='temp_cont.sav'.
EXECUTE.
variable labels col2 "50% P.I."/col1 " "/col4 "95% P.I."/col3 " "/col6 "99% P.I."/col5 " ".
GRAPH
/Title =' Prediction Intervals'
  /SCATTERPLOT(OVERLAY)=col2 col4 col6 !j  WITH col1 col3 col5 !i (PAIR)
  /MISSING=VARIABLEWISE .
!doend.
!doend.
!ENDDEFINE.