basic Module Reference

This module will provide some basic convenience routines Description. More...

Data Types
type	timer
	Simple timer. Holds start-time, stop-time, and time-difference. More...

Functions/Subroutines
integer function, public	is_inf (x)
	is_inf Checks if the argument is plus or minus infinite.
subroutine, public	print_msg (msg, sub, errcode, unit)
	Print a message, and optionally stop the program.

Variables
real(dp), parameter, public	zero = 0._dp
	Real cero.
real(dp), parameter, public	small = epsilon(1._dp)
	Real small number.
complex(dp), parameter, public	c_z0 = (0._dp, 0._dp)
	Complex cero.
complex(dp), parameter, public	c_r1 = (1._dp, 0._dp)
	Complex unit.
complex(dp), parameter, public	c_i1 = (0._dp, 1._dp)
	Complex imaginary unit.
real(dp), parameter, public	nf_minf = -huge(1._dp)
	Minus infinite.
real(dp), parameter, public	nf_inf = huge(1._dp)
	Positive infinite.
real(dp), parameter, public	m_pi = 3.14159265358979323846264338328_dp
real(dp), parameter, public	m_dpi = 6.28318530717958647692528676656_dp
	2*pi
real(dp), parameter, public	m_pi_2 = 1.57079632679489661923132169164_dp
	pi/2
real(dp), parameter, public	m_pi_4 = 0.78539816339744830966156608458_dp
	pi/4
real(dp), parameter, public	m_sqrtpi = 1.77245385090551602729816748334_dp
	sqrt(pi)
real(dp), parameter, public	m_2_sqrtpi = 1.12837916709551257389615890312_dp
	2/sqrt(pi)
real(dp), parameter, public	m_1_pi = 0.31830988618379067153776752675_dp
	1/pi
real(dp), parameter, public	m_2_pi = 0.63661977236758134307553505349_dp
	2/pi
real(dp), parameter, public	m_lnpi = 1.14472988584940017414342735135_dp
	ln(pi)
real(dp), parameter, public	m_ln2 = 0.693147180559945309417232121458176568_dp
	ln(2)
real(dp), parameter, public	m_e = 2.71828182845904523536028747135_dp
	e
real(dp), parameter, public	m_log2e = 1.442695040888963407359924681001892137_dp
	log_2 (e)
real(dp), parameter, public	m_log10e = 0.43429448190325182765112891892_dp
	log_10 (e)
real(dp), parameter, public	deg2rad = 0.017453292519943295_dp
	pi/180
real(dp), parameter, public	rad2deg = 57.295779513082320876654618_dp
	180/pi

Detailed Description

This module will provide some basic convenience routines Description.

Eventually it will provide:

• [X] types (real, double precision, infinite, etc)
• [X] Basic error handling (defining output for warning and errors) To improve maybe look into https://docs.python.org/3/library/warnings.html
• Some basic file handling (some os.path functionality) (Really needed?)
• [X] Some sys functionality (stdin, stdout, stderr via iso_fortran_env)
• [X] Timers, timestamp (a simple implementation)

For numerical work we need to use specific minimal precision which is machine-and-compiler-independent. The real type definitions emphatize this. The names are sp and dp are chosen only by tradition/historic reasons. We define types with at least 15 decimal places and exponent range of 307. (see for instance http://fortranwiki.org/fortran/show/Real+precision). We also could use c_double from module iso_c_binding (fortran 2003 and later)

Function/Subroutine Documentation

is_inf()

integer function, public is_inf

(

real(dp), intent(in)

x

)

is_inf Checks if the argument is plus or minus infinite.

Returns

Returns 0 if is finite, -1 if is minus-infinite and +1 if is plus-infinite

Parameters

[in]

x

Variable to test

References zero.

Referenced by timer::assignment().

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print_msg()

subroutine, public print_msg	(	character(len=*), intent(in)	msg,
		character(len=*), intent(in), optional	sub,
		integer, intent(in), optional	errcode,
		integer, intent(in), optional	unit )

Print a message, and optionally stop the program.

If errcode > 0 stop the program

Examples of use:

call print_msg("Invalid argument!", errcode=1) ! will stop the program with error code 1.
call print_msg("Invalid argument","my_sub",1)  ! will stop the program with error code 1.
call print_msg("Fishy values of argument","my_sub", errcode=3) ! will stop the program with error code 3.
call print_msg("Fishy values of argument", errcode=-3) ! will **NOT** stop the program. Show error code 3.
call print_msg("Fishy values of argument","my_sub", errcode=0) ! will **NOT** stop the program.
call print_msg("Fishy values of argument","my_sub", errcode=0, unit=13) ! will **NOT** stop the program.

The first three examples print the given message and stop the program. The next two will keep running after printing the message to stderr. The last will keep running after printing the message to a previously open file.

Parameters

[in]	msg	Message to print on stderr
[in]	sub	Routine name. Default = None
[in]	errcode	Error code. Default = 0
[in]	unit	Unit to write. Default = stderr

Referenced by timer::assignment(), csplines::cspl_clean(), csplevder::cspl_interpdev(), csplevder::cspl_interpdev_tab(), csplines::csplder(), csplines::csplrep(), histograms::histogram(), polynomial::polyder(), polynomial::polyint(), save_array::save_array1d(), and save_array::save_array2d().

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