Simulation of water surface wave propagation

The propagation of the wave surface of the water (water surface wave propagation) can be modeled by doing numerical modeling. Surface wave propagation is usually modeled using equations of momentum and continuity equations in 2 dimensions. Equation 2 (two) this dimension typically use a different approach was approached to, element to. A different method of approach to to 2 dimensions it is easier to use a different approach to the explicit and tough when approached with the implicit approach to difference to. The implicit approach is usually used for the difference up to 1 (one) model dimensions. For 2 dimensions if you want to forced approached with implicit method can but only implicit difference method approach to, so not the same as the implicit approach to 1 (one) dimensions.

The approach of implicit methods are better than explicit because numerical stability program better than the explicit difference method approach to.

Now it has developed approaches to differential equations by using a method of Fast Fourier Transform (FFT). However, the programs tend to run slower than using explicit and implicit difference approximation to.

In the Department of Civil Engineering, Engineering Faculty, University of Lampung, Indonesia, has already developed various numerical program to simulate the propagation of surface wave 2 (two) dimensions by using different types of wave equation as used by Goto and Ogawa (1992) to simulate the propagation of tsunami waves. Tsunami wave equation used by Kowalik (1993), the Boussinesq Equations (2005), some other equation and the equation of the hyperbola 2-d. All these equations are modeled, both to simulate a single wave propagation, such as the tsunami wave as well as to model the propagation of a wave of traveler through the breakwater and the breakwater sank.

Video simulation of propagation of wave surface can be seen as follows:

Draw 2-D contour figure using Python

File should be in ASCII format read in 2 dimensions (an example file can be downloaded). File to read it is called "baca_2d .py". The Python Script file is presented as follows,

Generate movie using Matlab ver 5.3.1

Surface wave propagation simulation movie, the movement of the bullet, and so on can be created by using a variety of softwares and a variety of ways. One of them is as will be explained here.

We can make movie simulation using Matlab program. Here matlab version 5.3.1 is used (old version). For Matlab version 6.0 upwards toolbox function to make the movie we can download it directly from Matlab (http://www.mathworks.com/matlabcentral/fileexchange/309).

Draw 2-D contour figure using Octave

Like previous writings, drawing the contours of diffraction wave 2 dimensions by using python. We may also use Octave for drawing contours 2 dimensions of the diffraction of waves propagated through the crack surfaces (example taken), in addition to using Python, Matlab, Scilab, and so on.

The File will be in ASCII format read surely in 2 dimensions (an example file can be downloaded).

File to read it is called "baca_data." m ". The Script of this file is as follows,

Editing sound wave file using octave

Manipulate sound files (sound wave files or *.wav files) often we need if we want to process the file is either for the purposes of reducing the file size as well as to learn or to filter the files in accordance with the purposes such as to see the frequency of sound waves that propagate in concrete, reduce noise and so on.

This time, I try to share my experience for users of Linux, how to manipulate a sound file (*.wav) using octave in linux (I use linux ubuntu version 10.04).
First of all, we record sound which we will take, it can use the program Audacity or Sweep on linux. This time I use the program Audacity like the following,

Applied Newton Raphson using Javascript

It contains material of numerical programming lecture. Here given the example calculations using Javascript. We can use a Javascript program to calculate the root of the equation. By way of iterations to get the value of the function f (x) = 0, the value of x can be defined as the following example,

1. Newton Raphson (program example)

contoh program 1

Translation: contoh program 1

Frequency analysis of daily rainfalls

Rainfall has periodic and stochastic properties. By using the technique of fourier transform, we can elaborate on the frequency of rainfall daily into the shape of the spectrum of daily rainfall that was presented in the relationship between the amplitude of the daily rainfall (mm) with daily rainfall period (days).

In the example was given of data time series of daily rainfall data of length 512 days.

Plot 1-D Graph using Python

Drawing graphs or plotting graphics in one dimension (x-y), we usually do by using a program such as excel Worksheet of the Spreadsheet from Microsoft Excel, Open Office, Gnumeric, or Matlab, and many more programs that can be used for this purpose. But when the data series is very long perhaps Excel Spreadsheet, Gnumeric, and OpenOfice were not able help us to draw a graph.