basic_m Module

This file defines a module containing the machine size of single-precision, double-precision, and quadruple-precision floating point numbers; to declare the floating point precision of a variable, use real(sp), real(dp), or real(qp) as the type of the variable. It also defines the working-precision, which will be the default kind for module procedures. As for module procedures, this library defines some common utility functions for working with e.g. complex numbers.

Contents

Variables

sp dp qp wp inf eps pi

Functions

re im cx arg unitvector nonzero

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)	Numerical infinity
real(kind=wp),	public,	parameter	::	eps	=	epsilon(1.0_wp)	Numerical infinitesimal
real(kind=wp),	public,	parameter	::	pi	=	atan(1.0_wp)*4.0_wp	Circle constant

Functions

public pure elemental function re(z) result(x)

Returns the real part of a complex number z=x+iy.

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Arguments

Type	Intent	Optional	Attributes		Name
complex(kind=wp),	intent(in)			::	z	Complex number

Return Value real(kind=wp)

Real part

public pure elemental function im(z) result(y)

Returns the imaginary part of a complex number z=x+iy.

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Arguments

Type	Intent	Optional	Attributes		Name
complex(kind=wp),	intent(in)			::	z	Complex number

Return Value real(kind=wp)

Imaginary part

public pure 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 pure 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	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	Vector

Return Value logical

Finite