Learntofish's Blog

A blog about math, physics and computer science

Archive for August, 2009

Understanding the Fourier Transform intuitively

Posted by Ed on August 28, 2009

In the following I will explain how the Fourier transform can be understood intuitively. We will start with basis vectors in \mathbb{R}^3 and make the transition to basis functions.

The Fourier Transform
For a function f(x) the Fourier transform is given by f(x)=\frac{1}{\sqrt{2\pi}} \int_{-\infty}^{+\infty} c(k) e^{ikx} dk with c(k) = \frac{1}{\sqrt{2 \pi}} \int_{-\infty}^{+\infty} f(t) e^{-ikt} dt (see here and here). In order to understand this formula we consider vectors in \mathbb{R}^3:
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Connect your Wiimote to PC

Posted by Ed on August 19, 2009

In the following I will describe how to connect your wiimote to a Windows PC, read some data from the wiimote and how to use Johnny Chung Lee’s virtual window program.

1) Connecting the wiimote to the PC Read the rest of this entry »

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Call by Value and Call by Reference

Posted by Ed on August 2, 2009

Today I’d like to talk about the difference between Call by Value and Call by Reference. I assume that you are familiar with pointers and references in C++, otherwise have a look at my blog posts on pointers and references.

We will write a function that squares a given integer variable. And we will do this in three different ways.
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References in C++

Posted by Ed on August 1, 2009

Last time I wrote about pointers in C++. Today I’d like to talk about references in C++. Let’s view the following source code:
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