The Fourier Transform

Pure mathematics is much more than an armory of tools and techniques for the applied mathematician. On the other hand, the pure mathematician has ever been grateful to applied mathematics for stimulus and inspiration. From the vibrations of the violin string they have drawn enchanting harmonies of Fourier Series, and to study the triode valve they have invented a whole theory of non-linear oscillations.

George Frederick James Temple In 100 Years of Mathematics: a Personal Viewpoint (1981).


The Fourier Transform (FT) is an integral transform, a powerful mathematical tool to map a function from its original space representation into another function space (called, in this case, the Fourier space). In the time domain, the Fourier space is the frequency and in the Cartesian domain is the so-called reciprocal space. The FT is accomplished by integrating the given function in its original space. The advantage of the FT is that in the transformed space, the properties of the original function can usually be characterised and manipulated more quickly than in the original function space. The FT function can generally be mapped back to the original function space using the inverse FT.

The FT plays an important role in pure and applied science, computer science, electronic engineering, and medicine. In this lecture, I will shortly introduce the mathematics of the FT and then show some examples of practical applications.

Continue reading

The Fourier Series

Pure mathematics is much more than an armory of tools and techniques for the applied mathematician. On the other hand, the pure mathematician has ever been grateful to applied mathematics for stimulus and inspiration. From the vibrations of the violin string they have drawn enchanting harmonies of Fourier Series, and to study the triode valve they have invented a whole theory of non-linear oscillations.

George Frederick James Temple In 100 Years of Mathematics: a Personal Viewpoint (1981).


Figure 1: Jean-Baptiste Joseph Fourier(source wikipedia)

The Fourier Series is a very important mathematics tool discovered by Jean-Baptiste Joseph Fourier in the 18th century. The Fourier series is used in many important areas of science and engineering. They are used to give an analytical approximate description of complex periodic function or series of data.  In this blog, I am going to give a short introduction to it.

Continue reading

La Serie​ di Taylor

La serie di Taylor è un utilissimo strumento matematico. In questo blog, ne darò una breve descrizione dando qualche esempio di applicazione.

Chi è il signor Taylor?

Brook Taylor (1685 – 1731) era un matematico britannico del XVII secolo che ha dimostrato la formula che porta il suo nome, e l’argomento di questo blog, nel volume Methodus Incrementorum Directa et Inversa (1715). Maggiori informazioni si possono trovare nella corrispondente pagina della wikipedia.

Continue reading

The Taylor Series

The Taylor series is a mathematical tool that, sometimes, it is not easy to immediately grasp by freshman students. In this blog, I will give a short review of it giving some examples of applications.

Who is Mr. Taylor?

Brook Taylor (1685 – 1731) was a 17th-century British mathematician. He demonstrated the celebrated Taylor formula, the topics of this blog, in his masterwork Methodus Incrementorum Directa et Inversa (1715). For more information, just give a read to the following wiki page.

Continue reading

Modelling Natural Pattens and Forms I: Sunflowers Florets and the Golden Ratio

Il girasole piega a occidente
e già precipita il giorno nel suo
occhio in rovina … 
from the poem  “Quasi un madrigale” by Salvatore Quasimodo.

Continue reading

Retro Programming II: the Amiga and the Computational Beauty of the Leaf

In my archaeological exploration of old computer files, I came across another simple but exciting Amiga Basic program I programmed in 1989. It is named “Foglie”, the Italian name for leaves. It was an attempt to explore some ideas of functional plant morphology modelling. The stimulus comes after the reading of the paper by Karl J. Niklas on issue 213 of Le Science (the Italian edition of the Scientific American magazine [1]). The article titled “Computer-simulated plant evolution” described the modelling of plants to study their interaction with the environment. It was a fascinating paper; still, simple and primitive graphics caught my imagination. Nowadays, the field of digital morphology has come to an age (just to mention one, Avatar), and we can have an idea of this progress in the level of realism in movies, video games, and TV programs. However, the organism’s form and shape have always caught my curiosity and interest. The structure of leaf nervation was an intriguing pattern related to my acquaintance with the fascinating fractals objects, another recurrent topic in the pages of scientific magazines of the period.

Continue reading

La programmazione in Awk II: Life in a Shell

Il gioco Life fu inventato negli anni ’70 dal prolifico matematico John H. Conway (vedi [5] per la sua biografia) ed è diventato famoso dopo la pubblicazione di Martin Gardner nella sua rubrica di matematica amatoriale sulla rivista Scientific American [1,2]. Il gioco è basato sugli automi cellulari concepiti da Konrad Zuse e Stanislaw M. Ulam all’inizio degli anni ’50, e poi adottati da John von Neumann per il suo studio sugli automi auto-replicanti [2,3]. Un automa cellulare è composto da unità (celle) interagenti disposte in una griglia quadrataIl sistema si evolve in cicli di vita in cui ogni cella cambia stato e nuove celle possono nascere e altre possono sopravvivere o, eventualmente, morire. Lo stato di ogni cella nel ciclo successivo è definito dall’interazione con le celle adiacenti in base a delle regole. L’interazione avviene con i primi vicini di ciascuna cella. Come mostrato nella Figura 1, è possibile utilizzare due tipi di intorni (cerchi) della cella centrale. Il gioco Life usa il tipo di proposto da Moore. 

Continue reading