在38楼已经贴出来， 虽然在学C语言但是不会写啊，只会写个hello world ， 但是能看懂点了。
我是把下面这两个程序结合起来了，放到我的程序里了。 结果能和程序1和这个网页版本对应起来
网页版正弦表计算：
http://www.daycounter.com/Calculators/Sine-Generator-Calculator.phtml
程序1
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
int main(int argc,char *argv[])
{
int entries, entries_2PI, phase, amplitude, offset, data_per_line;
int i, j;
int max, min, max_digits;
if (argc != 7) {
fprintf(stderr,"Generate C source code for sine table\n");
fprintf(stderr,"Usage:\n");
fprintf(stderr,"sinus_gen entries entries_per_2PI phase amplitude offset data_per_line >outputfile\n\n");
fprintf(stderr,"entries : number of entries in sine table\n");
fprintf(stderr,"entries_per_2PI : number of samples within full 360 degree\n");
fprintf(stderr,"phase : phase offset in samples\n");
fprintf(stderr,"amplitude : amplitude of sine wave, integer\n");
fprintf(stderr,"offset : offset of sine wave, integer\n");
fprintf(stderr,"data_per_line : number of samples per line in source file\n");
fprintf(stderr,">outputfile : redirect output form terminal to file\n");
return 1;
}
entries = atoi(argv[1]); //180
entries_2PI = atoi(argv[2]); //180
phase = atoi(argv[3]); // 0
amplitude = atoi(argv[4]); // 20
offset = atoi(argv[5]); // 20
data_per_line = atoi(argv[6]); // 输出多少行
min = abs(offset - amplitude);
max = abs(offset + amplitude);
max_digits=2;
if (min > 99 || max > 99) max_digits=3;
if (min > 999 || max > 999) max_digits=4;
if (min > 9999 || max > 9999) max_digits=5;
// header
printf("const int sinus[%d] = {\n\t", entries);
for (i=0, j=0; i<entries; i++) {
switch(max_digits) {
case 2: printf("%3d", (int)(offset + amplitude*sin((phase+i)*2*3.1415927/*3))); break;
case 3: printf("%4d", (int)(offset + amplitude*sin((phase+i)*2*3.1415927/entries_2PI))); break;
case 4: printf("%5d", (int)(offset + amplitude*sin((phase+i)*2*3.1415927/entries_2PI))); break;
case 5: printf("%6d", (int)(offset + amplitude*sin((phase+i)*2*3.1415927/entries_2PI))); break;
}
if (i < (entries-1)) {
printf(", ");
}
j++;
if (j==data_per_line) {
if (i < (entries-1)) {
printf("\n\t");
} else {
printf("\n");
}
j=0;
}
}
if (j !=0) printf("\n");
// footer
printf("};\n");
return 0;
}
程序2
#include "cordic-16bit.h"
#include <math.h> // for testing only!
//Print out sin(x) vs fp CORDIC sin(x)
int main(int argc, char **argv)
{
double p;
int s,c;
int i;
for(i=0;i<50;i++)
{
p = (i/50.0)*M_PI/2;
//use 32 iterations
cordic((p*MUL), &s, &c, 16);
//these values should be nearly equal
printf("%f : %f\n", s/MUL, sin(p));
}
}
cordic-16bit.h
//Cordic in 16 bit signed fixed point math
//Function is valid for arguments in range -pi/2 -- pi/2
//for values pi/2--pi: value = half_pi-(theta-half_pi) and similarly for values -pi---pi/2
//
// 1.0 = 16384
// 1/k = 0.6072529350088812561694
// pi = 3.1415926536897932384626
//Constants
#define cordic_1K 10000
#define half_pi 0x00006487
#define MUL 16384.000000
#define CORDIC_NTAB 16
int cordic_ctab [] = {0x00003243, 0x00001DAC, 0x00000FAD, 0x000007F5, 0x000003FE, 0x000001FF, 0x000000FF, 0x0000007F, 0x0000003F, 0x0000001F, 0x0000000F, 0x00000007, 0x00000003, 0x00000001, 0x00000000, 0x00000000, };
void cordic(int theta, int *s, int *c, int n)
{
int k, d, tx, ty, tz;
int x=cordic_1K,y=0,z=theta;
n = (n>CORDIC_NTAB) ? CORDIC_NTAB : n;
for (k=0; k<n; ++k)
{
d = z>>15;
//get sign. for other architectures, you might want to use the more portable version
//d = z>=0 ? 0 : -1;
tx = x - (((y>>k) ^ d) - d);
ty = y + (((x>>k) ^ d) - d);
tz = z - ((cordic_ctab[k] ^ d) - d);
x = tx; y = ty; z = tz;
}
*c = x; *s = y;
}
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