*
* KUMAC pour demontrer coupures a la Bayes en 2 dimensions
*                                      MP 6/95
opt nstat
opt nbox                                                                        
*                              Histogrammes pour la presentation
his/cre/2d 500 'Distribution x vs. y ' 20 -2. 2. 20 -2. 2.
his/cre/1d 501 'Distribution marginale en x' 20 -2. 2.
his/cre/1d 502 'Distribution marginale en y' 20 -2. 2.
*                              Lire l'echantillon (voir coulomb.kumac)
ne = 3101
vec/cre x1([ne])
vec/cre y1([ne])
vec/read x1 yotst.txt
vec/read y1 totst.txt
sigma x2 = x1 + .5
sigma y2 = y1 - .3
*                              Calculer moyennes, variances et correlation
sigma xm1=vsum(x1)/[ne]
sigma ym1=vsum(y1)/[ne]
sigma xm2=vsum(x2)/[ne]
sigma ym2=vsum(y2)/[ne]
sigma sx=sqrt(vsum((x1-xm1)**2)/[ne])
sigma sy=sqrt(vsum((y1-ym1)**2)/[ne])
sigma ro=(vsum((x1-xm1)*(y1-ym1))/[ne])/sx/sy
*                              Inversion a la main da V
sigma b = sx**2  ; sigma c = sx*sy*ro
sigma d = c      ; sigma e = sy**2
sigma x = 1./(b-c*d/e) ; sigma u = 1./(e-c*d/b)
sigma y = -c*u/b       ; sigma z = -d*x/e
sigma print x,y,z,u
sigma dx = (xm1-xm2)   ; sigma dy = (ym1-ym2)
sigma dmx = x*dx+y*dy  ; sigma dmy = z*dx+u*dy
sigma con = -.5*(dx*dmx+dy*dmy)
*                              Ligne coupure
sigma xl = -2.0  ; sigma xh =  2.0
sigma yl = (con-xl*dmx)/dmy  ; sigma yh = (con-xh*dmx)/dmy
*                              Presentation
zone 1 1
vec/hfill y1%x1 500
vec/hfill y2%x2 500
his/plot 500
line xm1 ym1 xm2 ym2
line xl yl xh yh