1.4 - Simple SCILAB Input and Output

Output: To get a list of your current session use the function diary. The format is as follows: diary (output_filename), where the filename is written within quotes. To end collecting output in the current diary output file use diary(0). For example, try the following session:

(Press Restart)
diary ('session1.txt')
A = [1. 2. 3.; 2. 3. 1.; 3. 2. 1.];b=[5; 4; -1.];
A
b
x = linsolve(A,b)
diary(0)
Next, use NOTEPAD, or other text editor, to open the file session1.txt to see the contents of the file.

Command Input: you can read SCILAB commands from a script file, which is basically a text file listing all the commands you want to use. As an example, create the following text file in the bin subdirectory of the SCILAB directory using NOTEPAD, and call it session2.txt:

//--------------------------------------------------------------------------
clear
A = [1. 2. -3. // entering
3. 4. 5. // elements of
7. 8. 9.] // matrix A
b = [1.; 2.; 3.] // enter vector b
xa = inv(A)*b // calculate x using matrix inverse
xb = linsolve(A,b) // calculate x using SCILAB's own linsolve function
//--------------------------------------------------------------------------
Then,press Restart in SCILAB, and type: exec('session2.txt'). You will see SCILAB execute all the commands in your file, stopping at the end of the file.

SCILAB command history: All commands entered in a given SCILAB session get stored into a SCILAB command history buffer. The commands are thus accessible for re-use or edition. All the command history functions are available through the option History under the File menu in the SCILAB worksheet. The most useful commands are cntl-P and cntl-N, which lets you access the previous command or the next command, respectively, in the command history buffer. Once a command is recalled from the command history buffer it can be edited by using the backspace or delete keys, or by inserting new characters by simply typing at the proper location.

Selective worksheet output: Suppose you have been working on a lengthy SCILAB session whose command history buffer contains some results that produced errors as well as some intermediary results that are not of interest to you for output. For your output, you can select only those commands relevant to your final results by using Cntl-P and Cntl-N. Try the following SCILAB session that explores some basic vector operations using vectors x and y:
1 - Press the Restart option in the menu bar.
2 - Enter the following SCILAB commands:
-->x = [1, 2, 5, -4]
x =
! 1. 2. 5. - 4. !
-->y = [0, 2, 3,-5]
y =
! 0. 2. 3. - 5. !
-->xy
!--error 10
inconsistent multiplication
-->x.y
ans =
! 0. 4. 15. 20. !
... -->diary(0) The session, except for the very first command () is stored in file c:\myVectors.txt. This file can be edited or printed from a text editor such as NOTEPAD, or my favorite, PFE (Programmer’s File Editor) available for free from: http://www.lancs.ac.uk/people/cpaap/pfe.

Current directory / creating a work directory: SCILAB uses a current directory where files are saved by default, for example when using the function diary. To see the current directory use:
-->pwd
Under a Windows operating system, the default current directory is typically c:\
The command pwd stands for print working directory.
I recommend that you create a sub-directory, or folder, called work and locate it under the SCILAB main directory. For example, under a Windows operating system, the SCILAB main directory will typically be c:\Program Files\SCILAB2.5
Thus, your work directory would correspond to:
c:\Program Files\SCILAB2.5\work
At the beginning of a SCILAB session, you can change the current directory to the work directory by using the function chdir:
--> chdir(‘c:\Program Files\SCILAB2.5\work’)
You can use your work directory to store scripts and functions that you create.