basic_m Module
- Jabir Ali Ouassou
-
- Foundation
- 46 statements
- Source File
This module contains constants and functions for doing low-level numerics in Fortran. This includes standard real and complex precisions (sp, dp, qp), a "working precision" (wp) that is used as the default precision in GENEUS; some common numerical constants (like pi and the machine epsilon); as well as basic functions for e.g. constructing and deconstructing complex numbers.
Uses
Variables
| Type | Visibility | Attributes | Name | Initial | |||
|---|---|---|---|---|---|---|---|
| integer, | public, | parameter | :: | sp | = | real32 |
Single precision |
| integer, | public, | parameter | :: | dp | = | real64 |
Double precision |
| integer, | public, | parameter | :: | qp | = | real128 |
Quadruple precision |
| integer, | public, | parameter | :: | wp | = | dp |
Working precision |
| real(kind=wp), | public, | parameter | :: | inf | = | huge(1.0_wp) |
Infinity |
| real(kind=wp), | public, | parameter | :: | eps | = | epsilon(1.0_wp) |
Infinitesimal |
| real(kind=wp), | public, | parameter | :: | pi | = | atan(1.0_wp)*4.0_wp |
Circle constant |
Functions
public elemental function re(z) result(x)
Returns the real part of a complex number z=x+iy.
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=wp), | intent(in) | :: | z |
Complex number |
Return Value real(kind=wp)
Real part
public elemental function im(z) result(y)
Returns the imaginary part of a complex number z=x+iy.
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=wp), | intent(in) | :: | z |
Complex number |
Return Value real(kind=wp)
Imaginary part
public elemental function cx(x, y) result(z)
Returns the complex number z=x+iy.
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=wp), | intent(in) | :: | x |
Real part |
||
| real(kind=wp), | intent(in), | optional | :: | y |
Imaginary part |
Return Value complex(kind=wp)
Complex number
public elemental function arg(z) result(t)
Returns the complex argument θ of a complex number z=r·exp(iθ).
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=wp), | intent(in) | :: | z |
Complex number |
Return Value real(kind=wp)
Complex argument
public pure function unitvector(v) result(r)
If the argument has a finite norm, then it will be rescaled to a unit vector. If that norm is zero, then a zero vector is returned instead.
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=wp), | intent(in), | dimension(3) | :: | v |
Input vector |
Return Value real(kind=wp), dimension(3)
Unit vector
public pure function nonzero(v) result(r)
Checks whether or not the argument has a finite norm.
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=wp), | intent(in), | dimension(:) | :: | v |
Input vector |
Return Value logical
Conclusion