4.12 SIN: Sinusoidal time dependent value

4.12.1 Syntax

SIN args
SIN offset amplitude frequency delay damping

4.12.2 Purpose

The component value is a sinusoidal function of time, with optional exponential decay.

4.12.3 Comments

For voltage and current sources, this is the same as the Spice SIN function, with some extensions.

It generates either a steady sinusoid, or a damped sinusoid.

If delay and damping are both zero, you get a steady sine wave at the specified frequency. Otherwise, you get a damped pulsed sine wave, starting after delay and damping out with a time constant of 1/damping.

The shape of the waveform is described by the following algorithm:

reltime = time - _delay
if (reltime > 0.){
 ev = _amplitude * sin(2*PI*_freq*reltime);
 if (_damping != 0.){
 ev *= exp(-reltime*_damping);
 }
 ev += _offset;
}else{
 ev = _offset;
}

For other components, it gives a time dependent value.

As an extension beyond Spice, you may specify the parameters as name=value pairs in any order.

4.12.4 Parameters

Offset = x

DC offset. (Default = 0.)

Amplitude = x

Peak amplitude. (Default = 1.)

Frequency = x

Frequency, Hz. (required)

Delay = x

Turn on delay, seconds. (Default = 0.)

Damping = x

Damping factor, 1/seconds. (Default = 0.)