char *fcvt( double value, int ndigit, int *decpt, int *sign )

	- prototype in stdlib.h

	- converts a floating pt number to a string of ndigit digits,
	  returning pointer to that string
	- correct digit is rounded for Fortran-F format output of the
	  number of digits equal to ndigit
	- decpt is position of decimal point (negative value means to left
	  of returned digits) and sign is 0 if positive, else negative