gausssums_multipleof6.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <complex.h>
   4 #include <math.h>
   5
   6 int readPaulicoeffs(int* alpha, int* beta, int* gamma, int* delta, int numqubits);
   7 complex double Gausssum1d(int quadraticcoeff, int linearcoeff);
   8 complex double Kroneck(int arg);
   9
  10 // order of matrix elements is [row][column]!!!
  11
  12 int main()
  13 {
  14
  15   int i;
  16   int x, y, xp, yp;
  17
  18   int N;              // number of qubits
  19   scanf("%d", &N);
  20   if(N%6!=0) {
  21     printf("Error: N must be a multiple of 6!\n");
  22     return 1;
  23   }
  24
  25   int alpha[N], beta[N], gamma[N], delta[N];
  26
  27   double complex summand, sum;
  28
  29   while(readPaulicoeffs(alpha, beta, gamma, delta, N)) {
  30
  31     /* for(i=0; i<N; i++) */
  32     /*   printf("%d %d %d %d\n", alpha[i], beta[i], gamma[i], delta[i]); */
  33
  34     sum = 1.0+0.0*I;
  35     for(i=0; i<N; i+=6) {
  36       summand = 0.0*I;
  37       for(y=0; y<=1; y++) {
  38         //for(x=0;x<=(y*(gamma[i]+gamma[i+1])+(y+1)*(gamma[i]+delta[i+1]))%2; x++) {
  39         for(x=y*(beta[i]+alpha[i+1]+beta[i+1])%2;x<=(y*(beta[i]+alpha[i+1]+beta[i+1])+y*(gamma[i]+gamma[i+1])+(y+1)*(gamma[i]+delta[i+1]))%2; x++) {
  40           for(yp=((gamma[i+3]+delta[i+4])*x)%2; yp<=(1+(gamma[i+3]+gamma[i+4])*x)%2; yp++) {
  41             //strange that I don't need the following modification to x
  42           //****for(yp=((gamma[i+3]+delta[i+4])*x*(1+alpha[i]+beta[i]))%2; yp<=(1+(gamma[i+3]+gamma[i+4])*x*(1+alpha[i]+beta[i]))%2; yp++) {
  43             for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
  44           //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
  45               summand += 2.0*(0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
  46                               + 0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
  47                 *(0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
  48                   + 0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
  49             }
  50           }
  51           for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
  52             for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
  53               summand += (0.125*pow(2.0,1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
  54                           + 0.125*pow(2.0,1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
  55                 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
  56             }
  57           }
  58           //for(yp=x; yp<=1; yp++) {
  59           for(yp=x*(1+alpha[i]+beta[i])%2; yp<=1; yp++) {
  60             //for(xp=(yp*(delta[i+3]+delta[i+4])+x)%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+x)%2; xp++) {
  61             for(xp=(yp*(delta[i+3]+delta[i+4])+x*(1+alpha[i]+beta[i]))%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+x*(1+alpha[i]+beta[i]))%2; xp++) {
  62               summand += 2.0*(0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
  63                           + 0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
  64                 *(0.125*(-I)*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
  65             }
  66           }
  67         }
  68       }
  69
  70       for(y=0; y<=(1+alpha[i+2])%2; y++) {
  71         for(x=0; x<=(1+beta[i+2])%2; x++) {
  72           for(yp=0; yp<=1; yp++) {
  73             for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
  74               //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
  75               summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
  76                 *(0.125*pow(2.0,1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2))*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
  77                   + 0.125*pow(2.0,1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2))*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
  78             }
  79           }
  80           for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
  81             for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
  82               summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
  83                 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
  84             }
  85           }
  86           for(yp=0; yp<=1; yp++) {
  87             for(xp=(yp*(delta[i+3]+delta[i+4]))%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4]))%2; xp++) {
  88               summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
  89                 *(0.125*(-I)*pow(2.0,(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
  90             }
  91           }
  92         }
  93       }
  94
  95       for(y=0; y<=1; y++) {
  96         for(x=(y*(delta[i]+delta[i+1]))%2; x<=(1+y*(gamma[i]+gamma[i+1]))%2; x++) {
  97           for(yp=((gamma[i+3]+delta[i+4])*y)%2; yp<=(1+(gamma[i+3]+gamma[i+4])*y)%2; yp++) {
  98             for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
  99               //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
 100               summand += 2.0*(0.125*pow(2.0,(pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
 101                 *(0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
 102                   + 0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
 103             }
 104           }
 105           for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
 106             for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
 107               summand += (0.125*pow(2.0,pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
 108                 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
 109             }
 110           }
 111           for(yp=y; yp<=1; yp++) {
 112             for(xp=(yp*(delta[i+3]+delta[i+4])+y)%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+y)%2; xp++) {
 113               summand += 2.0*(0.125*pow(2.0,(pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
 114                 *(0.125*(-I)*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
 115             }
 116           }
 117         }
 118       }
 119
 120       sum *= summand;
 121     }
 122     //printf("%lf+%lfI\n", creal(sum), cimag(sum));
 123     printf("%lf\n", cabs(creal(sum)));
 124
 125
 126   }
 127
 128   return 0;
 129 }
 130
 131 complex double Kroneck(int arg)
 132 {
 133   arg = (arg+1)%2; // output 1 if argument is 0 mod 2 and 0 otherwise
 134   return ((complex double)arg);
 135 }
 136
 137 complex double Gausssum1d(int quadraticcoeff, int linearcoeff)
 138 {
 139   /*****************************************
 140   /* NOTE! we assume coeffs are either 0 or 1
 141   /* (So you cannot pass off a linear coeff as a quadratic coeff by multiplying it by a factor of 2 (and considering it as mod 4)!)
 142   *****************************************/
 143
 144   quadraticcoeff %= 2;
 145   linearcoeff %= 2;
 146
 147   if(quadraticcoeff == 0)
 148     if(linearcoeff == 0)
 149       return 2.0+0.0*I;
 150     else
 151       return 0.0*I;
 152   else
 153     if(linearcoeff == 0)
 154       return 1.0+1.0*I;
 155     else
 156       return 1.0-1.0*I;
 157
 158 }
 159
 160 int readPaulicoeffs(int *alpha, int *beta, int *gamma, int *delta, int numqubits)
 161 {
 162
 163   int i;
 164
 165   if(scanf("%d %d %d %d", &alpha[0], &beta[0], &gamma[0], &delta[0]) != EOF) {
 166     for(i=1; i<numqubits; i++) {
 167       scanf("%d %d %d %d", &alpha[i], &beta[i], &gamma[i], &delta[i]);
 168     }
 169     return 1;
 170   } else
 171     return 0;
 172
 173 }
 174
 175
 176