Reference of all functions of Siglab - panel D functions.

 
Simple arithmetic functions that did not find place in panel A. There are no shortcuts for these buttons.
 

Buttons	Shortcut	Result and Explanation
		The pi constant (%pi in scilab notation).
		Statistics on the chosen signal The mean, the standard deviation, the min and the max of the current signal are worked out for the points available in the graphic window.
		Real part of a signal.
		Imaginary part of a signal.
		Phase of an imaginary signal (between -pi/2 and pi/2)
		Base 10 logarithm.
		20 * log10( signal ). The decibel expression of a signal (for amplitude, beware to db of a power value).

 

1. IIR

Infinite impulse response filter :
The output values are :

	y(t)=num(1)*x(t)+num(2)*x(t-1)+num(3)*x(t-2)...+den(1)*y(t-1)+den(2)*y(t-2)...

Where  x is the signal chosen, num and denum two vectors of coefficients given in a file *.fil. You may find examples of such files in the directory $SCILAB/siglab/test.
The file syntax is :

# a comment of any kind
# y(t)=x(t) + y(t-1) - 0.5 * y(t-2) + 0.2 y(t-2)
# the first line is the coefficients applyed to x(t)
1
# the second line is the coefficients applyed to y(t-1), y(t-2), ...
1 -0.5 0.2

 

2. Cut

Cut a portion of a matrix file signal :
The parameters are the following /

• signal to cut
• the point where to begin cutting
• the point where to stop cutting

The result is the restant parts of the original signal group together.
 

3. Paste

Paste the values held in the buffer from the new origin asked :
 

4. Dupplicate

Dupplication of a signal. All elements of a signal (name, formula, matrix, ...) are dupplicated in another signal. May be useful before a delay.

 

5. Execute

Execute a scilab program from within SigLab. When requiring a macro, just open your prefered editor, copy what you see on the scilab command line. At the end, replace loM(xxx) by loM($-yyy). $ represents the last signal, $-1 the one before, $-2 ... This will insure that you can call your macro at any time in siglab, it will process the signal that you wish. An example is available in home_of_scilab/siglab/test/exec_test.sci.