Hi all, I need to convert a floating point value from Microsoft Basic format to IEEE format. There's a simple way to achieve this in R or I have to write my own function? (e.g. convert the C code below)
thanks t #include <string.h> /* for strncpy */ int _fmsbintoieee(float *src4, float *dest4) { unsigned char *msbin = (unsigned char *)src4; unsigned char *ieee = (unsigned char *)dest4; unsigned char sign = 0x00; unsigned char ieee_exp = 0x00; int i; /* MS Binary Format */ /* byte order => m3 | m2 | m1 | exponent */ /* m1 is most significant byte => sbbb|bbbb */ /* m3 is the least significant byte */ /* m = mantissa byte */ /* s = sign bit */ /* b = bit */ sign = msbin[2] & 0x80; /* 1000|0000b */ /* IEEE Single Precision Float Format */ /* m3 m2 m1 exponent */ /* mmmm|mmmm mmmm|mmmm emmm|mmmm seee|eeee */ /* s = sign bit */ /* e = exponent bit */ /* m = mantissa bit */ for (i=0; i<4; i++) ieee[i] = 0; /* any msbin w/ exponent of zero = zero */ if (msbin[3] == 0) return 0; ieee[3] |= sign; /* MBF is bias 128 and IEEE is bias 127. ALSO, MBF places */ /* the decimal point before the assumed bit, while */ /* IEEE places the decimal point after the assumed bit. */ ieee_exp = msbin[3] - 2; /* actually, msbin[3]-1-128+127 */ /* the first 7 bits of the exponent in ieee[3] */ ieee[3] |= ieee_exp >> 1; /* the one remaining bit in first bin of ieee[2] */ ieee[2] |= ieee_exp << 7; /* 0111|1111b : mask out the msbin sign bit */ ieee[2] |= msbin[2] & 0x7f; ieee[1] = msbin[1]; ieee[0] = msbin[0]; return 0; } -- View this message in context: http://r.789695.n4.nabble.com/Floats-in-Microsoft-Basic-format-tp3732456p3732456.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.