Generate and return a scalar (or a vector of length size
or an array of the same shape as the input p
) containing the odds of getting a head
in a single (or a series) of coinflipping experiment(s).
The coin can be optionally biased toward getting a head (.true.
) with the input userspecified probability p
.
 Parameters

[in]  p  : The input scalar or array of arbitrary rank of type real of kind any supported by the processor (e.g., RK, RK32, RK64, or RK128) within the range [0, 1] , representing the probability of success/yes/true (or getting head in a coinflip).
A value other than p = 0.5 corresponds to a biased coinflip experiment.

If the input argument
size is present, then p must be a scalar.

If the input argument
size is missing, then p can be a scalar or array of arbitrary rank and shape.
(optional, default = 0.5 ) 
[in]  size  : The input scalar of type integer of default kind IK, representing the size of the output rand vector.
(optional, if present, then p must be a scalar and the output will be a vector.) 
 Returns
rand
: The output scalar or vector of length size
, or array of the same shape as the input p
of type logical
of default kind LK, containing the Bernoullidistributed random output value.
Possible calling interfaces ⛓
rand(
1:size)
= isHead(p, size)
!
Generate and return a scalar (or a vector of length size or an array of the same shape as the input p...
This module contains classes and procedures for generating Bernoullidistributed random numbers.
 Warning
 The input value for
p
must be a number between 0
and 1
.
This condition is verified only if the library is built with the preprocessor macro CHECK_ENABLED=1
.

Keep in mind that the interface
isHead()
uses a default singleprecision value p = .5
.
On the current hardware technology, this corresponds to a 32bit real
precision.
This implies a repeat cycle of \(\sim10^6\) for the generated random numbers.
If more random numbers are needed, specify the value p = .5_RKG
, where RKG
refers to a higher real precision kind capable of generating the desired number of random coinflipping.
 Note
 The procedure isHead() without any input arguments is equivalent to getUnifRand() without any input arguments.
 See also
 getBernRand
setBernRand
getUnifRand
setUnifRand
Example usage ⛓
10 type(display_type) :: disp
15 call disp%show(
"!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
16 call disp%show(
"! Flip a potentially biased coin (as determined by the success rate `p`).")
17 call disp%show(
"!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")
20 call disp%show(
"isHead() ! flip a fair coin.")
24 call disp%show(
"isHead(size = 5_IK) ! flip a fair coin 5 times.")
28 call disp%show(
"isHead(p = 0.5_RKS) ! flip a fair coin with real32bit precision.")
32 call disp%show(
"isHead(p = 0.5_RKD) ! flip a fair coin with real64bit precision.")
36 call disp%show(
"isHead(p = 0.5_RKH) ! flip a fair coin with real128bit precision.")
40 call disp%show(
"isHead(0.25) ! flip an unfair coin with 0.25 odds of success.")
44 call disp%show(
"isHead(0.25, size = 5_IK) ! flip an unfair coin with 0.25 odds of success 5 times.")
48 call disp%show(
"isHead(p = [0.05, 0.25, 0.75, 0.95]) ! flip four different unfair coins.")
This is a generic method of the derived type display_type with pass attribute.
This is a generic method of the derived type display_type with pass attribute.
This module contains classes and procedures for input/output (IO) or generic display operations on st...
type(display_type) disp
This is a scalar module variable an object of type display_type for general display.
This module defines the relevant Fortran kind typeparameters frequently used in the ParaMonte librar...
integer, parameter RK
The default real kind in the ParaMonte library: real64 in Fortran, c_double in CFortran Interoperati...
integer, parameter LK
The default logical kind in the ParaMonte library: kind(.true.) in Fortran, kind(....
integer, parameter IK
The default integer kind in the ParaMonte library: int32 in Fortran, c_int32_t in CFortran Interoper...
integer, parameter RKD
The double precision real kind in Fortran mode. On most platforms, this is an 64bit real kind.
integer, parameter SK
The default character kind in the ParaMonte library: kind("a") in Fortran, c_char in CFortran Intero...
integer, parameter RKH
The scalar integer constant of intrinsic default kind, representing the highestprecision real kind t...
integer, parameter RKS
The singleprecision real kind in Fortran mode. On most platforms, this is an 32bit real kind.
Generate and return an object of type display_type.
Example Unix compile command via Intel ifort
compiler ⛓
3ifort fpp standardsemantics O3 Wl,rpath,../../../lib I../../../inc main.F90 ../../../lib/libparamonte* o main.exe
Example Windows Batch compile command via Intel ifort
compiler ⛓
2set PATH=..\..\..\lib;%PATH%
3ifort /fpp /standardsemantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe
Example Unix / MinGW compile command via GNU gfortran
compiler ⛓
3gfortran cpp ffreelinelengthnone O3 Wl,rpath,../../../lib I../../../inc main.F90 ../../../lib/libparamonte* o main.exe
Example output ⛓
27isHead(p
= [
0.05,
0.25,
0.75,
0.95])
 Test:
 test_pm_distBern
Final Remarks ⛓
If you believe this algorithm or its documentation can be improved, we appreciate your contribution and help to edit this page's documentation and source file on GitHub.
For details on the naming abbreviations, see this page.
For details on the naming conventions, see this page.
This software is distributed under the MIT license with additional terms outlined below.

If you use any parts or concepts from this library to any extent, please acknowledge the usage by citing the relevant publications of the ParaMonte library.

If you regenerate any parts/ideas from this library in a programming environment other than those currently supported by this ParaMonte library (i.e., other than C, C++, Fortran, MATLAB, Python, R), please also ask the end users to cite this original ParaMonte library.
This software is available to the public under a highly permissive license.
Help us justify its continued development and maintenance by acknowledging its benefit to society, distributing it, and contributing to it.
 Copyright
 Computational Data Science Lab
 Author:
 Amir Shahmoradi, Oct 16, 2009, 11:14 AM, Michigan
Definition at line 160 of file pm_distBern.F90.