C++ · Software

FizzBuzz or the beauty of compile-time calculations in C++17

FizzBuzz is a popular test that is commonly used in job interviews for software developers. In this test one is asked to write a function that prints the numbers from 1 to 100. But for multiples of three “Fizz” has to be printed instead of the number and for the multiples of five the word… Continue reading FizzBuzz or the beauty of compile-time calculations in C++17

C++

C++11/14 for scientific computing VI

Floating-point exceptions During a numerical calculation various kinds of run-time errors may occur. In C++, such an error may be indicated via floating-point exceptions or via the (global but thread-local) variable errno. Floating-point exceptions are completely unrelated to C++ exceptions. When an floating-point exception is raised by an erroneous operation, the exception is simply noted… Continue reading C++11/14 for scientific computing VI

C++

Revisiting the named parameter idiom in C++14

Some programming languages have functions with named parameters. Named parameters let the programmer pass the parameters to a function in any order and they are distinguished by a name. So the programmer can explicitly pass all the needed parameters and default values without worrying about the order used in the function declaration. In C++, however,… Continue reading Revisiting the named parameter idiom in C++14

C++ · MPI · parallel computing

MPL – A message passing library

The Message Passing Interface (MPI) Standard defines a message passing library, which serves as the basis for many high-performance computing applications today. It provides portable scalable functions for data exchange in parallel computations for various parallel computing architectures. Originally application programing interfaces had been defined for C and Fortran as well as for C++. In… Continue reading MPL – A message passing library

C++

C++11/14 for scientific computing V

$\boldsymbol{\lambda}$ functions Anonymous functions, often called $\lambda$ functions, are a common feature of scientific programming languages, e.g., Male and Matlab. They are particularly usefull when functions are employed, which take other functions as arguments.  For example, a numerical root finding algorithm requires to specify a function as an input parameter. C++11 introduces $\lambda$ functions to… Continue reading C++11/14 for scientific computing V

C++

C++11/14 for scientific computing IV

Random numbers C++98 inherited from C the standard functions rand and srand and the macro RAND_MAX for generating pseudo-random numbers. These functions suffer several problems. For example, it has been never specified which algorithm is used in rand to produce pseudo-random numbers. Thus, in C and in C++98 the outcome of a Monte Carlo simulation… Continue reading C++11/14 for scientific computing IV

C++

C++11/14 for scientific computing III

Mathematical functions C++11/14 introduces several new mathematical functions, which are all overloaded for the types float, double and long double and that are defined in the header file cmath. The following table summerizes the new functions. Basic operations remainder signed remainder of the division operation remquo signed remainder as well as the three last bits… Continue reading C++11/14 for scientific computing III