--- /dev/null
+C Output from Public domain Ratfor, version 1.0
+
+C PURPOSE
+C Calculation of the cubic B-spline smoothness prior
+C for "usual" interior knot setup.
+C Uses BSPVD and INTRV in the CMLIB
+C sgm[0-3](nb) Symmetric matrix
+C whose (i,j)'th element contains the integral of
+C B''(i,.) B''(j,.) , i=1,2 ... nb and j=i,...nb.
+C Only the upper four diagonals are computed.
+
+ subroutine sgram(sg0,sg1,sg2,sg3,tb,nb)
+
+c implicit none
+C indices
+ integer nb
+ DOUBLE precision sg0(nb),sg1(nb),sg2(nb),sg3(nb), tb(nb+4)
+c -------------
+ integer ileft,mflag, i,ii,jj, lentb
+ DOUBLE precision vnikx(4,3),work(16),yw1(4),yw2(4), wpt
+c
+c integer interv
+c external interv
+
+ lentb=nb+4
+C Initialise the sigma vectors
+ do 1 i=1,nb
+ sg0(i)=0.d0
+ sg1(i)=0.d0
+ sg2(i)=0.d0
+ sg3(i)=0.d0
+ 1 continue
+
+ ileft = 1
+ do 2 i=1,nb
+C Calculate a linear approximation to the
+C second derivative of the non-zero B-splines
+C over the interval [tb(i),tb(i+1)].
+C call intrv(tb(1),(nb+1),tb(i),ilo,ileft,mflag)
+ call interv(tb(1), nb+1,tb(i), ileft, mflag)
+C Left end second derivatives
+C call bspvd (tb,4,3,tb(i),ileft,4,vnikx,work)
+ call bsplvd (tb,lentb,4,tb(i),ileft,work,vnikx,3)
+C Put values into yw1
+ do 4 ii=1,4
+ yw1(ii) = vnikx(ii,3)
+ 4 continue
+
+C Right end second derivatives
+C call bspvd (tb,4,3,tb(i+1),ileft,4,vnikx,work)
+ call bsplvd (tb,lentb,4,tb(i+1),ileft,work,vnikx,3)
+
+C Slope*(length of interval) in Linear Approximation to B''
+ do 6 ii=1,4
+ yw2(ii) = vnikx(ii,3) - yw1(ii)
+ 6 continue
+
+ wpt = tb(i+1) - tb(i)
+C Calculate Contributions to the sigma vectors
+ if(ileft.ge.4) then
+ do 10 ii=1,4
+ jj=ii
+ sg0(ileft-4+ii) = sg0(ileft-4+ii) +
+ & wpt*(yw1(ii)*yw1(jj)+
+ & (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & + yw2(ii)*yw2(jj)*0.3330d0)
+ jj=ii+1
+ if(jj.le.4)then
+ sg1(ileft+ii-4) = sg1(ileft+ii-4) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ jj=ii+2
+ if(jj.le.4)then
+ sg2(ileft+ii-4) = sg2(ileft+ii-4) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ jj=ii+3
+ if(jj.le.4)then
+ sg3(ileft+ii-4) = sg3(ileft+ii-4) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ 10 continue
+
+ else if(ileft.eq.3)then
+ do 20 ii=1,3
+ jj=ii
+ sg0(ileft-3+ii) = sg0(ileft-3+ii) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ jj=ii+1
+ if(jj.le.3)then
+ sg1(ileft+ii-3) = sg1(ileft+ii-3) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ jj=ii+2
+ if(jj.le.3)then
+ sg2(ileft+ii-3) = sg2(ileft+ii-3) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ 20 continue
+
+ else if(ileft.eq.2)then
+ do 28 ii=1,2
+ jj=ii
+ sg0(ileft-2+ii) = sg0(ileft-2+ii) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ jj=ii+1
+ if(jj.le.2)then
+ sg1(ileft+ii-2) = sg1(ileft+ii-2) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ endif
+ 28 continue
+
+ else if(ileft.eq.1)then
+ do 34 ii=1,1
+ jj=ii
+ sg0(ileft-1+ii) = sg0(ileft-1+ii) +
+ & wpt* (yw1(ii)*yw1(jj) +
+ * (yw2(ii)*yw1(jj) + yw2(jj)*yw1(ii))*0.5d0
+ & +yw2(ii)*yw2(jj)*0.3330d0 )
+ 34 continue
+
+ endif
+ 2 continue
+
+ return
+ end
projects / mothur.git / blobdiff