www.pudn.com > CRGAB.zip > NCVS.C

/* 
HEADER:         ; 
TITLE:          BASIC ncvs() function in C 
VERSION:        1.4; 
 
DESCRIPTION:    performs function of BASIC ncvs(), unpacking a string 
                of 4 chars previously packed by mks() 
 
KEYWORDS:       ncvs,single precision,BASIC; 
SYSTEM:         Xenix 3.4b, MSDOS; 
FILENAME:       ncvs.c 
WARNINGS:       compile with -dNO_PROTOTYPE if your system does not 
                support prototyping, with -dFOR_MSDOS if you are compiling 
                for MSDOS with an ANSI standard compiler. 
                Defaults assume compiling with prototypes for 
                Xenix 3.4b on Altos 2086 computer. 
 
SEE-ALSO:       vmks(); 
AUTHORS:        Vern Martin, 449 W. Harrison, Alliance, Ohio 44601; 
                My thanks to Mike Thompson of ACT Consulting in 
                Canton, Ohio for his help several years ago to write 
                the original version. 
COMPILERS:      ECOSOFT ECO-C88, XENIX 3.4B STANDARD COMPILER; 
*/ 
 
#include "vernmath.h" 
 
#define WIDTH 4 
#define XTYPE float 
#define KTYPE float 
 
double ncvs(string) 
char *string; 
{ 
    int i,s,e; 
    XTYPE x = (XTYPE) 1; 
    unsigned char c[WIDTH]; 
    static KTYPE k[WIDTH] = { 
        (KTYPE) 1.1920928955078125e-07, 
        (KTYPE) 3.0517578125000000e-05, 
        (KTYPE) 7.8125000000000000e-03, 
    }; 
 
/* convert chars to unsigned chars */ 
        for (i=0;i<=WIDTH-1;i++) { 
        c[i] = (unsigned char) string[i]; 
    } 
/* last char in string determines power to raise final total by */ 
    e=c[WIDTH-1]-129; 
 
/* determine sign */ 
/* next to last char determines sign */ 
    if (c[WIDTH-2] < (unsigned char) 128) { 
        s=1;  /* if it is positive, sign is 1 */ 
    } 
    else { 
        s = (-1); 
        /* make it think its positive */ 
        c[WIDTH-2] -= (unsigned char) 128; 
    } 
 
/* total first 3 chars multiplied by there respective factors */ 
    for (i=0;i