雜七雜八的kewang部落格

昨天晚上在上GA的時候，老師說上課要用Matlab，可是我是用linux，哪來的Matlab可以用，雖然Matlab有linux版，可是聽說要10張小朋友。

所以我就找了一些資料，發現在linux下有蠻多Matlab的替代軟體，像是Octave, Rlab還有R，這三套在linux上好像都蠻多人在用的。

Octave的首頁就這樣說了，「相容於Matlab」，所以拿來代替Matlab應該是再恰當也不過了。

GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with Matlab. It may also be used as a batch-oriented language.

Rlab的首頁則是這樣子表示，「Rlab想要做的比Matlab更好」，可是原來的作者Ian Searle已經停止開發了。停止開發四年後，有另一位叫做Marijan Kostrum的人接手了Rlab的這個計畫，後來發展成Rlab plus。這感覺怎麼跟BMP和BMPx的關係好像 XDDDD

Rlab is an interactive, interpreted scientific programming environment. Rlab is a very high level language intended to provide fast prototyping and program development, as well as easy data-visualization, and processing. Rlab is not a clone of languages such as those used by tools like Matlab or Matrix-X/Xmath. However, as Rlab focuses on creating a good experimental environment (or laboratory) in which to do matrix math, it can be called ``Matlab-like''; since the programming language possesses similar operators and concepts.

R的首頁是說，「R是一個統計計算的語言」，感覺上好像跟Matlab的用處不同，所以我也沒有繼續再研究了。

R is a language and environment for statistical computing and graphics. It is a GNU project which is similar to the S language and environment which was developed at Bell Laboratories (formerly AT&T, now Lucent Technologies) by John Chambers and colleagues. R can be considered as a different implementation of S. There are some important differences, but much code written for S runs unaltered under R.

總之我現在是使用Octave了啦。要安裝Octave很簡單，反正就是apt-get就對了
sudo apt-get install octave2.9

不過Octave沒有內附的image generator，所以我們要利用gnuplot這套軟體來幫助Octave產生圖形。
sudo apt-get install gnuplot

安裝好之後我們就可以開始使用Octave啦，只要在終端機輸入octave就可以了

首先先輸入一個簡單的函式，看看能不能使用Octave+gnuplot來繪圖。

x=[0 2 4 7 10 12]
y=[3 4 0 6 1 3]
plot(x,y)


如果有出現下面的這個圖，那就大功告成啦！



參考資料：
Octave
Rlab Web Site
Welcome to the RLaB plus 1.0 website
The R Project for Statistical Computing
gnuplot homepage
幾個可以處理矩陣的計算機: octave/rlab/R