Intel® Fortran Compiler 18.0 Developer Guide and Reference
Elemental Intrinsic Function (Generic): Returns the absolute spacing of model numbers near the argument value.
result = SPACING (x)
x |
(Input) Must be of type real. |
The result type and kind are the same as x. The result has the value b e-p. Parameters b, e, and p are defined in Model for Real Data. If the result value is outside of the real model range, the result is TINY( x).
If 3.0 is a REAL(4) value, SPACING (3.0) has the value 2 -22.
The following shows another example:
REAL(4) res4
REAL(8) res8, r2
res4 = SPACING(3.0) ! returns 2.384186E-07
res4 = SPACING(-3.0) ! returns 2.384186E-07
r2 = 487923.3
res8 = SPACING(r2) ! returns 5.820766091346741E-011