float value를 string으로 바꿔주는 함수 및 사용법

#include <math.h>

char *int_str (int value, int width, int trim)

{

static char asc_string[21]; // string to be built

int digit,save_value,i,j;

char sign;

if (width > 10) 

width = 10; // Set maximum number length

save_value = value; // save a copy of the initial number

value = abs(value); // take absolute value

// loop extracting BCD digits

for (i=1; i<=width; i++) {

digit = value % 10; // extract low order digit

asc_string[width - i] = digit+0x30;

value = value / 10;

}

asc_string[width]=0; // add string terminator

// trim leading zeros and insert sign if trim is true

if (trim == 1) {

// search for first significant digit

for (i=0; i< (width-1); i++)

if (asc_string[i] != (char) 0x30) break;

// insert the sign if negative

if (save_value < 0) {

i --;

asc_string[i] = (char) "-"; // insert the sign

}

// copy string left adjusted

for (j = 0; j <= (width - i); j++)

asc_string [j] = asc_string [j+i];

}

return asc_string;

}

// Int_Str -- convert binary number to signed BCD string equivalent

// with no leading zeros

char *int_str_trim (int value)

{

return int_str (value, 10, 1);

}

void *float_to_string(float val, int dp)

{

int dpVal=1;

int dp1, intPart, fracPart;

static char asc_string[41]; // string to be built

if(dp>8) dp=8;         // set a maximum number of decimal places

dp1 = dp;

intPart=(int)val;

//Extract the fractional part

//Generate the required scale factor

while (dp1>0) {

dpVal=dpVal*10;

dp1--;

}

// Compute fraction

fracPart =(int) fabsf((val - intPart) *dpVal + 0.5F);

strcpy(asc_string, int_str_trim (intPart)); // place integer portion in string

strcat(asc_string, "."); // add decimal

strcat(asc_string, int_str (fracPart,dp,0)); // extract the decimal portion

return asc_string;

}

void main()

{

float a, b, c;

    float d, e;

a = 3.0;

b = 2.1;

c = a/b;

    d = log10f(100.0); 

e = powf(10.0, 2.2);

a = expf(4.0);

xil_printf("\n\r%s", float_to_string(d, 2));

xil_printf("\n\r%s", float_to_string(e, 2));

xil_printf("\n\r%s", float_to_string(a, 2));

}