◆ D1mach()

Function D1mach ( I As Long )

Machine parameters (double precision floating-point arithmetic)

Purpose: Determines the machine parameters on double precision floating-point arithmetic.

Returns: Double
The value specified by I. (0 will be returned if I is invalid.)

Parameters

[in] I Specifies the value to be returned.
= 1: B^(L-1), the smallest positive magnitude.
= 2: B^U*(1 - B^(-T)), the largest magnitude.
= 3: B^(-T), the smallest relative spacing.
= 4: B^(1-T), the largest relative spacing.
= 5: Log10(B)

Note: Assume floating-point numbers are represented in the t-digit, base-B form
sign (B^e)*((x(1)/B) + ... + (x(t)/B^t))
where 0 <= x(i) < B for i = 1, ..., t, 0 < x(1), and L <= e <= U.
The values of B, t, L and U are provided in I1mach().

Reference: SLATEC