M File Conversion C code

Parametet.m
Clc;clear;load ('src.mat'20482048= Exp (-j* (2*pi/8192= exp (j*1*pi/);

This file lists the parameters used in the value case, Src.mat file is the original data stored in MATLAB, data: 2048*1 data, each data is scientific notation.

Load command, you can load data from a file into a project for later use (how to use it, and also rely on a modular simulation diagram).

CZT_W/A are the complex numbers in exponential form: the operations of complex numbers are defined in the complex--<complex> in the C + + language, including the exponential operations of complex numbers--pow (A, b) =a^b and exp (a) =e^a.

The form of complex numbers defined in C + +: Complex <double> var_name (Real_port,imag_port);

This is similar to the definition of a complex variable is called a real and virtual part of the function of assignment, in fact, in C + + is a definition of a class, the definition of complex is the definition of the object, to the complex assignment can only be initialized mode assignment-call constructor assignment, the second assignment is the object assignment value. (Current knowledge of ....) ）

Define the form of a plural class (similar)

Class Complex

{

Public

Double Real_port;

Double Imag_port;

};

For example:

Complex <double> ABC (1.2,3.12);

So:

Abc= (1.2,3.12)

Real (ABC) = 1.2; IMAG (ABC) =3.12

Complex <double> BBB; BBB=ABC; -->bbb= (1.2,3.12)

With this understanding, so:

Parameter.h is good to write.

1#include <complex>2#include <vector>3#include <iostream>4 5 using namespacestd;6 7 DoublePI =3.14159265359;8 9 intCzt_n =2048;Ten intCzt_m =2048; OneComplex <Double> Czt_w_1 (0,-2*pi/8192); AComplex <Double> Czt_w =exp (czt_w_1); -Complex <Double> czt_a_1 (0, pi/ the); -Complex <Double> CZT_A = exp (czt_w_1);

CZT.M:
function y=CZT (u,czt_n,czt_m,czt_w,czt_a) L= Czt_m + czt_n; %l=4096g= Zeros (L,1); %G is a full 0 matrix of L row 1 columns forI=0: czt_n-1%Matrix G element Assignment g (I+1,1) = czt_a^ (-i) *czt_w^ (i^2/2) *u (i+1,1); ENDG=FFT (g); h= Zeros (L,1); forI=0: czt_m-1H (I+1,1) =czt_w^ (-i^2/2); End fori=l-czt_n+1: L-1H (I+1,1) =czt_w^ (-(l-i) ^2/2); end H=FFT (h); Q=h.*g;q=Ifft (Q); X=zeros (Czt_m,1); forI=0: czt_m-1X (i+1,1) =czt_w^ (i^2/2) *q (i+1); Endy=x;

The czt.m file defines a function--czt. (The file name is the same as the function name)

function is a keyword in MATLAB that defines functions, Y is the return value, U,czt_n,czt_m,czt_w,czt_a, represents the parameter, and the function is understood by: U,czt_n,czt_m,czt_w,czt_ A these parameters go through a series of steps to get the process of outputting y, these steps are the function body, where u represents what? , it is a matrix, the element is the data in the Src.mat file, so u is a 2048*1 matrix (the matrix can be replaced with an array in the C locale).

Command the entire: The calculation methods used are: FFT, Ifft, the matrix of the point multiplication, the complex number of the exponential operation.

L = Czt_m + czt_n; %l=4096= Zeros (L,1); %g for L row 1 columns of all 0 matrices for  i=0: czt_n-1 Matrix g element Assignment    g (i+1,1 ) = czt_a^ (-i) *czt_w^ (i^2/2) *u (i+1,1); ENDG=fft (g);

In writing this part of the code, the first thing to do is to do some preparatory work:

1, G matrix is a 4096*1 matrix, can be replaced with one-dimensional array, the element of the array is a complex character.

2, the elements of the U matrix are stored in the form of a file before this, to read into the U variable (src_real.txt only recorded the real part, Src_imag.txt only recorded the imaginary part)

3, G = Zeros (l,1) represents the variable initialization process, so the array is initialized.

4, it is noteworthy that the G here to participate in the operation below, so it can not be a function of local variables, but also to extract the FFT function, so that it can be accessed in subsequent calculations.

1 //test_9.cpp: Defines the entry point of the console application. 2 //3 4#include"stdafx.h"5#include <vector>6#include <complex>7#include <iostream>8#include"Parameter.h"9#include"fftw3.h"Ten#include <stdlib.h> One#include <malloc.h> A  -  -Complex <Double> u[2048]; the  - /*********** read raw data to Matrix (array u) ***************/ - voidSrc_txt_u () - { +         intI=0; -         DoubleU_real=0; +         Doubleu_imag=0; A  atFILE *fp_1,*fp_2; -Fp_1=fopen ("Real_src.txt","R"); -         if(fp_1==NULL) -cout<<"Fopen_error"<<Endl; -Fp_2=fopen ("Imag_src.txt","R"); -         if(fp_2==NULL) incout<<"Fopen_error"<<Endl; -  to          for(i=0;i<2048; i++) +         { -FSCANF (Fp_1,"%LF",&u_real); theFSCANF (fp_2,"%LF",&u_imag); *Complex <Double>U_mid (u_real,u_imag); $u[i]=U_mid;Panax Notoginseng         } - fclose (fp_1); the fclose (fp_2); +}

When reading data from a file into a variable, the function used is--fscanf ().

Since complex numbers are both defined and assigned, they are done at the same time and cannot be executed separately, so this defines an intermediate variable--u_mid it to assign the final complex number to the corresponding variable-the element of the array.

1 /************** calculation g=fft (g) **************/2Complex <Double>*Fft_g ()3 {4     //Get Matrix G5Complex <Double> *G;6     intl=czt_n+czt_m;7g = (Complex <Double> *)malloc(sizeof(Complex <Double>) *L);8      for(intI=0; i<czt_n;i++)9G[i]=pow (czt_a,-i) *pow (czt_w,i*i/2)*U[i];Ten  One     //FFT calculation AFftw_complex *in_put,*Out_put; -Complex <Double> *G_mid; -G_mid = (Complex <Double> *)malloc(sizeof(Complex <Double>) *2048); the Fftw_plan p_1; -     intN =2048; -in_put= (fftw_complex*) Fftw_malloc (sizeof(Fftw_complex) *N); -out_put= (fftw_complex*) Fftw_malloc (sizeof(Fftw_complex) *N); +      for(intI=0; i < N; i++) -     { +in_put[i][0] =Real (g[i]); Ain_put[i][1] =imag (G[i]); at         //printf ("%lf+%lfj\n", in_put[i][0],in_put[i][1]); -     } -p_1=fftw_plan_dft_1d (N,in_put,out_put, Fftw_forward, fftw_estimate); - Fftw_execute (p_1); -      for(intj =0; J < n;j++) -     { inComplex <Double> Var_mid (out_put[j][0],out_put[j][1]); -g_mid[j]=Var_mid; to     } +      -      for(intj =0; J < n;j++) the     { *         //printf ("%lf+%lfj\n", Real (G_mid[j]), Imag (G_mid[j])); $     }Panax Notoginseng Fftw_destroy_plan (p_1); - Fftw_free (in_put); the Fftw_free (out_put); +     returnG_mid; A}

Note the point:

1, when defining the G array, cannot use: Complex <double> g[l] This form, because L is a variable, then the static definition of the array is not feasible. In a dynamic definition, be sure to allocate enough space, where the G array represents the 4096*1 matrix space, then malloc (sizeof (complex <double>) *l space is required. If you only define a complex number of spaces (complex <double> *g), then only the first element position can be stored, and the other elements cannot be used.

2. Fftw_complex types and Compelx <double> types of data cannot be cast or implicitly converted, but can be assigned using both real and virtual parts:

for (int i=0; i < N; i++)
{
In_put[i][0] = Real (g[i]);
IN_PUT[I][1] = Imag (G[i]);
}

for (int j = 0;j < n;j++)

{

Complex <double> Var_mid (out_put[j][0],out_put[j][1]);
G_mid[j]=var_mid;
}

　　

M File Conversion C code