discrete = truefalse

samplecount = posint

sampletime = positive

hertz = truefalse

The Chirp command generates a linear chirp waveform, that is, a sinusoidal waveform whose frequency varies linearly with time.

By default, Chirp returns an expression representing the waveform. If the option discrete is assigned true, Chirp returns a Vector of data points.

The optional parameter yht specifies the height of the signal. Its default value is one.

The optional parameter f0 specifies the initial frequency of the waveform. Its default value is one. The units of f are radians/second unless the option parameter hertz is assigned true, in which case the units are hertz.

The optional parameter k specifies the rate of frequency increase with time. Its default value is one. The instantaneous frequency is f0 + k*(t-t0).

The optional parameter t0 specifies the start time of the waveform. Its default value is zero.

The optional parameter y0 specifies the vertical offset. Its default value is zero.

$\mathrm{with}\left(\mathrm{DynamicSystems}\right)\:$

$\mathrm{Chirp}\left(\right)$

$\left\{\begin{array}{cc}0& t<0\\ \sin \left(\left(1+t\right)t\right)& \mathrm{otherwise}\end{array}\right.$

$\mathrm{Chirp}\left(\mathrm{ypk}\&comma;\mathrm{f0}\&comma;k\&comma;\mathrm{t0}\&comma;\mathrm{y0}\right)$

$\left\{\begin{array}{cc}\mathrm{y0}& t<\mathrm{t0}\\ \mathrm{y0}+\mathrm{ypk}\sin \left(\left(\mathrm{f0}+k\left(-\mathrm{t0}+t\right)\right)\left(-\mathrm{t0}+t\right)\right)& \mathrm{otherwise}\end{array}\right.$

$\mathrm{Chirp}\left(\mathrm{hertz}=\mathrm{true}\right)$

$\left\{\begin{array}{cc}0& t<0\\ \sin \left(2\mathrm{\pi }\left(1+t\right)t\right)& \mathrm{otherwise}\end{array}\right.$

$\mathrm{evalf}\left[2\right]\left({\mathrm{Chirp}\left(\mathrm{discrete}=\mathrm{true}\right)}^{\mathrm{\%T}}\right)$

$\left[\begin{array}{cccccccccc}0.& 0.91& \mathrm{-0.28}& \mathrm{-0.54}& 0.91& \mathrm{-0.99}& \mathrm{-0.92}& \mathrm{-0.52}& 0.25& 0.89\end{array}\right]$

$\mathrm{plot}\left(\mathrm{Chirp}\left(1\&comma;0\&comma;\frac{1}{8}\&comma;0\&comma;0\&comma;\mathrm{hertz}=\mathrm{true}\right)\&comma;t=0..4\right)$