Timur A. Fatkhullin
5279d1c41a
start developing of FITPACK C++ bindings mount_server.cpp: fix compilation error with GCC15
105 lines
3.9 KiB
Fortran
105 lines
3.9 KiB
Fortran
recursive subroutine bispev(tx,nx,ty,ny,c,kx,ky,x,mx,y,my,z,
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* wrk,lwrk,iwrk,kwrk,ier)
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implicit none
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c subroutine bispev evaluates on a grid (x(i),y(j)),i=1,...,mx; j=1,...
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c ,my a bivariate spline s(x,y) of degrees kx and ky, given in the
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c b-spline representation.
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c
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c calling sequence:
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c call bispev(tx,nx,ty,ny,c,kx,ky,x,mx,y,my,z,wrk,lwrk,
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c * iwrk,kwrk,ier)
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c
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c input parameters:
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c tx : real array, length nx, which contains the position of the
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c knots in the x-direction.
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c nx : integer, giving the total number of knots in the x-direction
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c ty : real array, length ny, which contains the position of the
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c knots in the y-direction.
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c ny : integer, giving the total number of knots in the y-direction
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c c : real array, length (nx-kx-1)*(ny-ky-1), which contains the
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c b-spline coefficients.
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c kx,ky : integer values, giving the degrees of the spline.
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c x : real array of dimension (mx).
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c before entry x(i) must be set to the x co-ordinate of the
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c i-th grid point along the x-axis.
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c tx(kx+1)<=x(i-1)<=x(i)<=tx(nx-kx), i=2,...,mx.
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c mx : on entry mx must specify the number of grid points along
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c the x-axis. mx >=1.
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c y : real array of dimension (my).
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c before entry y(j) must be set to the y co-ordinate of the
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c j-th grid point along the y-axis.
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c ty(ky+1)<=y(j-1)<=y(j)<=ty(ny-ky), j=2,...,my.
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c my : on entry my must specify the number of grid points along
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c the y-axis. my >=1.
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c wrk : real array of dimension lwrk. used as workspace.
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c lwrk : integer, specifying the dimension of wrk.
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c lwrk >= mx*(kx+1)+my*(ky+1)
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c iwrk : integer array of dimension kwrk. used as workspace.
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c kwrk : integer, specifying the dimension of iwrk. kwrk >= mx+my.
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c
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c output parameters:
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c z : real array of dimension (mx*my).
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c on successful exit z(my*(i-1)+j) contains the value of s(x,y)
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c at the point (x(i),y(j)),i=1,...,mx;j=1,...,my.
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c ier : integer error flag
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c ier=0 : normal return
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c ier=10: invalid input data (see restrictions)
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c
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c restrictions:
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c mx >=1, my >=1, lwrk>=mx*(kx+1)+my*(ky+1), kwrk>=mx+my
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c tx(kx+1) <= x(i-1) <= x(i) <= tx(nx-kx), i=2,...,mx
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c ty(ky+1) <= y(j-1) <= y(j) <= ty(ny-ky), j=2,...,my
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c
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c other subroutines required:
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c fpbisp,fpbspl
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c
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c references :
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c de boor c : on calculating with b-splines, j. approximation theory
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c 6 (1972) 50-62.
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c cox m.g. : the numerical evaluation of b-splines, j. inst. maths
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c applics 10 (1972) 134-149.
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c dierckx p. : curve and surface fitting with splines, monographs on
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c numerical analysis, oxford university press, 1993.
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c
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c author :
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c p.dierckx
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c dept. computer science, k.u.leuven
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c celestijnenlaan 200a, b-3001 heverlee, belgium.
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c e-mail : Paul.Dierckx@cs.kuleuven.ac.be
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c
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c latest update : march 1987
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c
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c ..scalar arguments..
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integer nx,ny,kx,ky,mx,my,lwrk,kwrk,ier
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c ..array arguments..
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integer iwrk(kwrk)
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real*8 tx(nx),ty(ny),c((nx-kx-1)*(ny-ky-1)),x(mx),y(my),z(mx*my),
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* wrk(lwrk)
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c ..local scalars..
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integer i,iw,lwest
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c ..
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c before starting computations a data check is made. if the input data
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c are invalid control is immediately repassed to the calling program.
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ier = 10
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lwest = (kx+1)*mx+(ky+1)*my
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if(lwrk.lt.lwest) go to 100
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if(kwrk.lt.(mx+my)) go to 100
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if (mx.lt.1) go to 100
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if (mx.eq.1) go to 30
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go to 10
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10 do 20 i=2,mx
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if(x(i).lt.x(i-1)) go to 100
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20 continue
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30 if (my.lt.1) go to 100
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if (my.eq.1) go to 60
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go to 40
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40 do 50 i=2,my
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if(y(i).lt.y(i-1)) go to 100
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50 continue
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60 ier = 0
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iw = mx*(kx+1)+1
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call fpbisp(tx,nx,ty,ny,c,kx,ky,x,mx,y,my,z,wrk(1),wrk(iw),
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* iwrk(1),iwrk(mx+1))
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100 return
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end
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