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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
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tree4464880c571602d54f6ae114729bf62a89518057 /math/ieee/chap1/fr4syn.f
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+c
+c-----------------------------------------------------------------------
+c subroutine: fr4syn
+c radix 4 synthesis
+c-----------------------------------------------------------------------
+c
+c
+ subroutine fr4syn(int, nn, b0, b1, b2, b3, b4, b5, b6, b7)
+ dimension l(15), b0(2), b1(2), b2(2), b3(2), b4(2), b5(2), b6(2),
+ * b7(2)
+ common /const/ pii, p7, p7two, c22, s22, pi2
+ equivalence (l15,l(1)), (l14,l(2)), (l13,l(3)), (l12,l(4)),
+ * (l11,l(5)), (l10,l(6)), (l9,l(7)), (l8,l(8)), (l7,l(9)),
+ * (l6,l(10)), (l5,l(11)), (l4,l(12)), (l3,l(13)), (l2,l(14)),
+ * (l1,l(15))
+c
+ l(1) = nn/4
+ do 40 k=2,15
+ if (l(k-1)-2) 10, 20, 30
+ 10 l(k-1) = 2
+ 20 l(k) = 2
+ go to 40
+ 30 l(k) = l(k-1)/2
+ 40 continue
+c
+ piovn = pii/float(nn)
+ ji = 3
+ jl = 2
+ jr = 2
+c
+ do 120 j1=2,l1,2
+ do 120 j2=j1,l2,l1
+ do 120 j3=j2,l3,l2
+ do 120 j4=j3,l4,l3
+ do 120 j5=j4,l5,l4
+ do 120 j6=j5,l6,l5
+ do 120 j7=j6,l7,l6
+ do 120 j8=j7,l8,l7
+ do 120 j9=j8,l9,l8
+ do 120 j10=j9,l10,l9
+ do 120 j11=j10,l11,l10
+ do 120 j12=j11,l12,l11
+ do 120 j13=j12,l13,l12
+ do 120 j14=j13,l14,l13
+ do 120 jthet=j14,l15,l14
+ th2 = jthet - 2
+ if (th2) 50, 50, 90
+ 50 do 60 k=1,int
+ t0 = b0(k) + b1(k)
+ t1 = b0(k) - b1(k)
+ t2 = b2(k)*2.0
+ t3 = b3(k)*2.0
+ b0(k) = t0 + t2
+ b2(k) = t0 - t2
+ b1(k) = t1 + t3
+ b3(k) = t1 - t3
+ 60 continue
+c
+ if (nn-4) 120, 120, 70
+ 70 k0 = int*4 + 1
+ kl = k0 + int - 1
+ do 80 k=k0,kl
+ t2 = b0(k) - b2(k)
+ t3 = b1(k) + b3(k)
+ b0(k) = (b0(k)+b2(k))*2.0
+ b2(k) = (b3(k)-b1(k))*2.0
+ b1(k) = (t2+t3)*p7two
+ b3(k) = (t3-t2)*p7two
+ 80 continue
+ go to 120
+ 90 arg = th2*piovn
+ c1 = cos(arg)
+ s1 = -sin(arg)
+ c2 = c1**2 - s1**2
+ s2 = c1*s1 + c1*s1
+ c3 = c1*c2 - s1*s2
+ s3 = c2*s1 + s2*c1
+c
+ int4 = int*4
+ j0 = jr*int4 + 1
+ k0 = ji*int4 + 1
+ jlast = j0 + int - 1
+ do 100 j=j0,jlast
+ k = k0 + j - j0
+ t0 = b0(j) + b6(k)
+ t1 = b7(k) - b1(j)
+ t2 = b0(j) - b6(k)
+ t3 = b7(k) + b1(j)
+ t4 = b2(j) + b4(k)
+ t5 = b5(k) - b3(j)
+ t6 = b5(k) + b3(j)
+ t7 = b4(k) - b2(j)
+ b0(j) = t0 + t4
+ b4(k) = t1 + t5
+ b1(j) = (t2+t6)*c1 - (t3+t7)*s1
+ b5(k) = (t2+t6)*s1 + (t3+t7)*c1
+ b2(j) = (t0-t4)*c2 - (t1-t5)*s2
+ b6(k) = (t0-t4)*s2 + (t1-t5)*c2
+ b3(j) = (t2-t6)*c3 - (t3-t7)*s3
+ b7(k) = (t2-t6)*s3 + (t3-t7)*c3
+ 100 continue
+ jr = jr + 2
+ ji = ji - 2
+ if (ji-jl) 110, 110, 120
+ 110 ji = 2*jr - 1
+ jl = jr
+ 120 continue
+ return
+ end