ikront.c

java-fft-demo,用java开发的实现fft的平台

/********************************************************/
/*IkronT						*/
/*Maritza Rodr韌uez Mart韓ez				*/
/*Computational Signal Processing Group - march-98   	*/
/*CSPG - Dr. Domingo Rodr韌uez - Coordinator         	*/
/*							*/
/*Description:						*/
/*This function ikront performs the product between the */
/*tensor product of the matrices IM and TN,S, where IM  */
/*is the identity matrix of order M, and TN,S is the 	*/
/*stride matrix of order S. The parameter of this 	*/
/*function are M, Nand S.				*/
/********************************************************/

COMPLEX **IkronT(int M,int N,int S)
{
   COMPLEX **tride,**IkronT_VAR;
   int R=N/S,MN = M*N, temp,auxR=0,auxS=0,l=0,m,k,i,j;
   tride = getComplexMatrix(N);
   IkronT_VAR = getComplexMatrix(MN);

   for(i = 0; i < N; i++)
      for(j = 0; j < N; j++){
	     if(j == i){
		    tride[i][j].real = cos((2*PI*auxR*auxS)/N);
		    tride[i][j].imag = -sin((2*PI*auxR*auxS)/N);
		    ++auxR;
			   if(auxR==R){ auxR=0; auxS=1;}
	        }
	    else{
		   tride[i][j].real=0.0;
		   tride[i][j].imag=0.0;
	    }
      }

   l=0;
   for(m = 0; m < (M*N); ++m) /* este es el valor de filas *columnas*/
   {
	  k=0;
	  if (m % N ==0 & m!=0 ) /* el valor para comparar m debe ser el num de columnas de B*/
	    l++;

	temp = M;

   for (i = 0; i < temp; ++i)/* numero de filas o columnas mayor entre A y B*/
   {
	for ( j = 0; j < N; ++j)/* numero de filas o columnas de B*/
    {
       if((l % M)== i){
	      IkronT_VAR[m][k].real = tride[m % N][j].real; /* m%filas o columnas de B*/
	      IkronT_VAR[m][k].imag = tride[m % N][j].imag;
	   	  k++;
       }
       else{
          IkronT_VAR[m][k].real =0.0;
	      IkronT_VAR[m][k].imag =0.0;
	      k++;
	   }
    }
   }
   }free(tride);
return IkronT_VAR;
}