27 subroutine biquad(z,glamn,glomn,dla,dlo,
28 *nla,nlo,maxla,maxlo,xla,xlo,val)
55 implicit real*8 (a-h,o-z)
59 real*4 x,y,fx0,fx1,fx2,qterp
64 ratla = difla / (dla/2.d0)
66 if(mod(ila,2).ne.0)
then 73 if(jla.gt.nla-2)jla = nla-2
78 ratlo = diflo / (dlo/2.d0)
80 if(mod(ilo,2).ne.0)
then 87 if(jlo.gt.nlo-2)jlo = nlo-2
94 x=(xlo-dlo*(jlo-1)-glomn)/dlo
103 *
'FATAL in biquad: x<0 : ',f20.10,/,
104 *
' --> Returning with val = ',f40.1)
113 *
'FATAL in biquad: x>2 : ',f20.10,/,
114 *
' --> Returning with val = ',f40.1)
121 y=(xla-dla*(jla-1)-glamn)/dla
130 *
'FATAL in biquad: y<0 : ',f20.10,/,
131 *
' --> Returning with val = ',f40.1)
140 *
'FATAL in biquad: y>2 : ',f20.10,/,
141 *
' --> Returning with val = ',f40.1)
153 fx0=qterp(x,z(jla ,jlo),z(jla ,jlo+1),z(jla ,jlo+2))
154 fx1=qterp(x,z(jla+1,jlo),z(jla+1,jlo+1),z(jla+1,jlo+2))
155 fx2=qterp(x,z(jla+2,jlo),z(jla+2,jlo+1),z(jla+2,jlo+2))
156 val=dble(qterp(y,fx0,fx1,fx2))
subroutine biquad(z, glamn, glomn, dla, dlo, nla, nlo, maxla, maxlo, xla, xlo, val)
Subroutine to perform a 2-D quadratic ("biquadratic") interpolation.