38 lines
568 B
C++
38 lines
568 B
C++
#include "nr.h"
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void NR::mpinv(Vec_O_UCHR &u, Vec_I_UCHR &v)
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{
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const int MF=4;
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const DP BI=1.0/256.0;
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int i,j,mm;
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DP fu,fv;
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int n=u.size();
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int m=v.size();
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Vec_UCHR s(n+m),r(2*n+m);
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mm=MIN(MF,m);
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fv=DP(v[mm-1]);
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for (j=mm-2;j>=0;j--) {
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fv *= BI;
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fv += v[j];
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}
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fu=1.0/fv;
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for (j=0;j<n;j++) {
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i=int(fu);
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u[j]=(unsigned char) i;
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fu=256.0*(fu-i);
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}
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for (;;) {
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mpmul(s,u,v);
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mplsh(s);
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mpneg(s);
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s[0] += (unsigned char) 2;
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mpmul(r,s,u);
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mplsh(r);
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mpmov(u,r);
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for (j=1;j<n-1;j++)
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if (s[j] != 0) break;
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if (j==n-1) return;
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}
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}
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