aboutsummaryrefslogtreecommitdiff
path: root/math/surfit/sf_beval.x
diff options
context:
space:
mode:
authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
commit40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch)
tree4464880c571602d54f6ae114729bf62a89518057 /math/surfit/sf_beval.x
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/surfit/sf_beval.x')
-rw-r--r--math/surfit/sf_beval.x143
1 files changed, 143 insertions, 0 deletions
diff --git a/math/surfit/sf_beval.x b/math/surfit/sf_beval.x
new file mode 100644
index 00000000..301967f9
--- /dev/null
+++ b/math/surfit/sf_beval.x
@@ -0,0 +1,143 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+# SF_BCHEB -- Procedure to evaluate all the non-zero Chebyshev functions for
+# a set of points and given order.
+
+procedure sf_bcheb (x, npts, order, k1, k2, basis)
+
+real x[npts] # array of data points
+int npts # number of points
+int order # order of polynomial, order = 1, constant
+real k1, k2 # normalizing constants
+real basis[ARB] # basis functions
+
+int k, bptr
+
+begin
+ bptr = 1
+ do k = 1, order {
+
+ if (k == 1)
+ call amovkr (1., basis, npts)
+ else if (k == 2)
+ call altar (x, basis[bptr], npts, k1, k2)
+ else {
+ call amulr (basis[1+npts], basis[bptr-npts], basis[bptr],
+ npts)
+ call amulkr (basis[bptr], 2., basis[bptr], npts)
+ call asubr (basis[bptr], basis[bptr-2*npts], basis[bptr], npts)
+ }
+
+ bptr = bptr + npts
+ }
+end
+
+
+# SF_BLEG -- Procedure to evaluate all the non zero Legendre function
+# for a given order and set of points.
+
+procedure sf_bleg (x, npts, order, k1, k2, basis)
+
+real x[npts] # number of data points
+int npts # number of points
+int order # order of polynomial, 1 is a constant
+real k1, k2 # normalizing constants
+real basis[ARB] # array of basis functions
+
+int k, bptr
+real ri, ri1, ri2
+
+begin
+ bptr = 1
+
+ do k = 1, order {
+ if (k == 1)
+ call amovkr (1., basis, npts)
+ else if (k == 2)
+ call altar (x, basis[bptr], npts, k1, k2)
+ else {
+ ri = k
+ ri1 = (2. * ri - 3.) / (ri - 1.)
+ ri2 = - (ri - 2.) / (ri - 1.)
+ call amulr (basis[1+npts], basis[bptr-npts], basis[bptr],
+ npts)
+ call awsur (basis[bptr], basis[bptr-2*npts],
+ basis[bptr], npts, ri1, ri2)
+ }
+
+ bptr = bptr + npts
+ }
+end
+
+
+# SF_BSPLINE1 -- Evaluate all the non-zero spline1 functions for a set
+# of points.
+
+procedure sf_bspline1 (x, npts, npieces, k1, k2, basis, left)
+
+real x[npts] # set of data points
+int npts # number of points
+int npieces # number of polynomial pieces minus 1
+real k1, k2 # normalizing constants
+real basis[ARB] # basis functions
+int left[ARB] # indices of the appropriate spline functions
+
+int k
+
+begin
+ call altar (x, basis[1+npts], npts, k1, k2)
+ call achtri (basis[1+npts], left, npts)
+ call aminki (left, npieces, left, npts)
+
+ do k = 1, npts {
+ basis[npts+k] = basis[npts+k] - left[k]
+ basis[k] = 1. - basis[npts+k]
+ }
+end
+
+
+# SF_BSPLINE3 -- Procedure to evaluate all the non-zero basis functions
+# for a cubic spline.
+
+procedure sf_bspline3 (x, npts, npieces, k1, k2, basis, left)
+
+real x[npts] # array of data points
+int npts # number of data points
+int npieces # number of polynomial pieces minus 1
+real k1, k2 # normalizing constants
+real basis[ARB] # array of basis functions
+int left[ARB] # array of indices for first non-zero spline
+
+int i
+pointer sp, sx, tx
+
+begin
+ # allocate space
+ call smark (sp)
+ call salloc (sx, npts, TY_REAL)
+ call salloc (tx, npts, TY_REAL)
+
+ # calculate the index of the first non-zero coeff
+ call altar (x, Memr[sx], npts, k1, k2)
+ call achtri (Memr[sx], left, npts)
+ call aminki (left, npieces, left, npts)
+
+ # normalize x to 0 to 1
+ do i = 1, npts {
+ Memr[sx+i-1] = Memr[sx+i-1] - left[i]
+ Memr[tx+i-1] = 1. - Memr[sx+i-1]
+ }
+
+ # calculate the basis function
+ call apowkr (Memr[tx], 3, basis, npts)
+ do i = 1, npts {
+ basis[npts+i] = 1. + Memr[tx+i-1] * (3. + Memr[tx+i-1] * (3. -
+ 3. * Memr[tx+i-1]))
+ basis[2*npts+i] = 1. + Memr[sx+i-1] * (3. + Memr[sx+i-1] * (3. -
+ 3. * Memr[sx+i-1]))
+ }
+ call apowkr (Memr[sx], 3, basis[1+3*npts], npts)
+
+ # release space
+ call sfree (sp)
+end