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Diffstat (limited to 'math/deboor/progs/prog6.f')
| -rw-r--r-- | math/deboor/progs/prog6.f | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/math/deboor/progs/prog6.f b/math/deboor/progs/prog6.f new file mode 100644 index 00000000..10c55c1f --- /dev/null +++ b/math/deboor/progs/prog6.f @@ -0,0 +1,23 @@ +chapter x. example 3. construction and evaluation of the pp-representat- +c ion of a b-spline. +c from * a practical guide to splines * by c. de boor +calls bsplpp(bsplvb),ppvalu(interv) +c + integer ia,l + real bcoef(7),break(5),coef(4,4),scrtch(4,4),t(11),value,x + real ppvalu +c set knot sequence t and b-coeffs for b(4,4,t) .... + data t / 4*0.,1.,3.,4.,4*6. /, bcoef / 3*0.,1.,3*0. / +c construct pp-representation .... + call bsplpp ( t, bcoef, 7, 4, scrtch, break, coef, l ) +c +c as a check, evaluate b(4,4,t) from its pp-repr. on a fine mesh. +c the values should agree with (some of) those generated in +c example 2 . + do 20 ia=1,40 + x = float(ia)*.2 - 1. + value = ppvalu ( break, coef, l, 4, x, 0 ) + 20 print 620, x, value + 620 format(f10.1,f20.8) + stop + end |