1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
|
subroutine fpbfou(t,n,par,ress,resc)
c subroutine fpbfou calculates the integrals
c /t(n-3)
c ress(j) = ! nj,4(x)*sin(par*x) dx and
c t(4)/
c /t(n-3)
c resc(j) = ! nj,4(x)*cos(par*x) dx , j=1,2,...n-4
c t(4)/
c where nj,4(x) denotes the cubic b-spline defined on the knots
c t(j),t(j+1),...,t(j+4).
c
c calling sequence:
c call fpbfou(t,n,par,ress,resc)
c
c input parameters:
c t : real array,length n, containing the knots.
c n : integer, containing the number of knots.
c par : real, containing the value of the parameter par.
c
c output parameters:
c ress : real array,length n, containing the integrals ress(j).
c resc : real array,length n, containing the integrals resc(j).
c
c restrictions:
c n >= 10, t(4) < t(5) < ... < t(n-4) < t(n-3).
c ..
c ..scalar arguments..
integer n
real*8 par
c ..array arguments..
real*8 t(n),ress(n),resc(n)
c ..local scalars..
integer i,ic,ipj,is,j,jj,jp1,jp4,k,li,lj,ll,nmj,nm3,nm7
real*8 ak,beta,con1,con2,c1,c2,delta,eps,fac,f1,f2,f3,one,quart,
* sign,six,s1,s2,term
c ..local arrays..
real*8 co(5),si(5),hs(5),hc(5),rs(3),rc(3)
c ..function references..
real*8 cos,sin,abs
c ..
c initialization.
one = 0.1e+01
six = 0.6e+01
eps = 0.1e-07
quart = 0.25e0
con1 = 0.5e-01
con2 = 0.12e+03
nm3 = n-3
nm7 = n-7
if(par.ne.0.) term = six/par
beta = par*t(4)
co(1) = cos(beta)
si(1) = sin(beta)
c calculate the integrals ress(j) and resc(j), j=1,2,3 by setting up
c a divided difference table.
do 30 j=1,3
jp1 = j+1
jp4 = j+4
beta = par*t(jp4)
co(jp1) = cos(beta)
si(jp1) = sin(beta)
call fpcsin(t(4),t(jp4),par,si(1),co(1),si(jp1),co(jp1),
* rs(j),rc(j))
i = 5-j
hs(i) = 0.
hc(i) = 0.
do 10 jj=1,j
ipj = i+jj
hs(ipj) = rs(jj)
hc(ipj) = rc(jj)
10 continue
do 20 jj=1,3
if(i.lt.jj) i = jj
k = 5
li = jp4
do 20 ll=i,4
lj = li-jj
fac = t(li)-t(lj)
hs(k) = (hs(k)-hs(k-1))/fac
hc(k) = (hc(k)-hc(k-1))/fac
k = k-1
li = li-1
20 continue
ress(j) = hs(5)-hs(4)
resc(j) = hc(5)-hc(4)
30 continue
if(nm7.lt.4) go to 160
c calculate the integrals ress(j) and resc(j),j=4,5,...,n-7.
do 150 j=4,nm7
jp4 = j+4
beta = par*t(jp4)
co(5) = cos(beta)
si(5) = sin(beta)
delta = t(jp4)-t(j)
c the way of computing ress(j) and resc(j) depends on the value of
c beta = par*(t(j+4)-t(j)).
beta = delta*par
if(abs(beta).le.one) go to 60
c if !beta! > 1 the integrals are calculated by setting up a divided
c difference table.
do 40 k=1,5
hs(k) = si(k)
hc(k) = co(k)
40 continue
do 50 jj=1,3
k = 5
li = jp4
do 50 ll=jj,4
lj = li-jj
fac = par*(t(li)-t(lj))
hs(k) = (hs(k)-hs(k-1))/fac
hc(k) = (hc(k)-hc(k-1))/fac
k = k-1
li = li-1
50 continue
s2 = (hs(5)-hs(4))*term
c2 = (hc(5)-hc(4))*term
go to 130
c if !beta! <= 1 the integrals are calculated by evaluating a series
c expansion.
60 f3 = 0.
do 70 i=1,4
ipj = i+j
hs(i) = par*(t(ipj)-t(j))
hc(i) = hs(i)
f3 = f3+hs(i)
70 continue
f3 = f3*con1
c1 = quart
s1 = f3
if(abs(f3).le.eps) go to 120
sign = one
fac = con2
k = 5
is = 0
do 110 ic=1,20
k = k+1
ak = k
fac = fac*ak
f1 = 0.
f3 = 0.
do 80 i=1,4
f1 = f1+hc(i)
f2 = f1*hs(i)
hc(i) = f2
f3 = f3+f2
80 continue
f3 = f3*six/fac
if(is.eq.0) go to 90
is = 0
s1 = s1+f3*sign
go to 100
90 sign = -sign
is = 1
c1 = c1+f3*sign
100 if(abs(f3).le.eps) go to 120
110 continue
120 s2 = delta*(co(1)*s1+si(1)*c1)
c2 = delta*(co(1)*c1-si(1)*s1)
130 ress(j) = s2
resc(j) = c2
do 140 i=1,4
co(i) = co(i+1)
si(i) = si(i+1)
140 continue
150 continue
c calculate the integrals ress(j) and resc(j),j=n-6,n-5,n-4 by setting
c up a divided difference table.
160 do 190 j=1,3
nmj = nm3-j
i = 5-j
call fpcsin(t(nm3),t(nmj),par,si(4),co(4),si(i-1),co(i-1),
* rs(j),rc(j))
hs(i) = 0.
hc(i) = 0.
do 170 jj=1,j
ipj = i+jj
hc(ipj) = rc(jj)
hs(ipj) = rs(jj)
170 continue
do 180 jj=1,3
if(i.lt.jj) i = jj
k = 5
li = nmj
do 180 ll=i,4
lj = li+jj
fac = t(lj)-t(li)
hs(k) = (hs(k-1)-hs(k))/fac
hc(k) = (hc(k-1)-hc(k))/fac
k = k-1
li = li+1
180 continue
ress(nmj) = hs(4)-hs(5)
resc(nmj) = hc(4)-hc(5)
190 continue
return
end
|