sinc, a MATLAB code which evaluates the sinc() function, its first and second derivative and its antiderivative. The normalized function is defined by sincn=sin(pi*x)/(pi*x), the unnormalized function is sincu=sin(x)/x. Plots of these functions are made.
Note that the MATLAB Signal Processing Toolbox includes an implementation of the sinc() function.
The information on this web page is distributed under the MIT license.
sinc is available in a C version and a C++ version and a Fortran77 version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.
humps, a MATLAB code which evaluates the humps() function, its first and second derivatives, and its antiderivative. The functions are plotted.
runge, a MATLAB code which evaluates the Runge() function, its first and second derivatives, and its antiderivative. This function causes a breakdown for polynomial interpolation over equally spaced nodes in [-1,+1]. Plots of these functions are made.
sigmoid, a MATLAB code which evaluates the sigmoid function s(x)=1/(1+exp(-x)) or its derivatives of any order. The test code creates graphic images.
steinerberger, a MATLAB code which evaluates the Steinerberger function, a continuous function with discontinuous derivative, which is very hard to accurately plot, integrate, minimize, or interpolate. Plots of these functions are made.