Create Signals#

This section describes how to create new signals from various mathematical models.

../../_images/s_create.png

Screenshot of the “Create” menu.#

When the “Signal Panel” is selected, the menus and toolbars are updated to provide signal-related actions.

The “Create” menu allows you to create new signals from various models (see below).

New signal#

Create a new signal from various models:

Icon

Model

Equation

../../_images/1d-zero.svg

Zero

\(y[i] = 0\)

../../_images/1d-normal.svg

Normal distribution

\(y[i]\) is normally distributed with configurable mean and standard deviation

../../_images/1d-poisson.svg

Poisson distribution

\(y[i]\) is Poisson distributed with configurable mean

../../_images/1d-uniform.svg

Uniform distribution

\(y[i]\) is uniformly distributed between two configurable bounds

../../_images/gaussian.svg

Gaussian

\(y = y_{0}+\dfrac{A}{\sqrt{2\pi} \cdot \sigma} \cdot \exp\left(-\dfrac{1}{2} \cdot \left(\dfrac{x-x_{0}}{\sigma}\right)^2\right)\)

../../_images/lorentzian.svg

Lorentzian

\(y = y_{0}+\dfrac{A}{\sigma \cdot \pi} \cdot \dfrac{1}{1+\left(\dfrac{x-x_{0}}{\sigma}\right)^2}\)

../../_images/voigt.svg

Voigt

\(y = y_{0}+A \cdot \dfrac{\Re\left(\exp\left(-z^2\right) \cdot \erfc(-j \cdot z)\right)}{\sqrt{2\pi} \cdot \sigma}\) with \(z = \dfrac{x-x_{0}-j \cdot \sigma}{\sqrt{2} \cdot \sigma}\)

../../_images/planck.svg

Blackbody (Planck’s law)

\(y = \dfrac{2 h c^2}{\lambda^5 \left(\exp\left(\dfrac{h c}{\lambda k T}\right)-1\right)}\)

../../_images/sine.svg

Sine

\(y = y_{0}+A\sin\left(2\pi \cdot f \cdot x+\phi\right)\)

../../_images/cosine.svg

Cosine

\(y = y_{0}+A\cos\left(2\pi \cdot f \cdot x+\phi\right)\)

../../_images/sawtooth.svg

Sawtooth

\(y = y_{0}+A \left( 2 \left( f x + \frac{\phi}{2\pi} - \left\lfloor f x + \frac{\phi}{2\pi} + \frac{1}{2} \right\rfloor \right) \right)\)

../../_images/triangle.svg

Triangle

\(y = y_{0}+A \sawtooth\left(2 \pi f x + \phi, \text{width} = 0.5\right)\)

../../_images/square.svg

Square

\(y = y_0 + A \sgn\left( \sin\left( 2\pi f x + \phi \right) \right)\)

../../_images/sinc.svg

Cardinal sine

\(y = y_0 + A \sinc\left(2\pi f x + \phi\right)\)

../../_images/linear_chirp.svg

Linear chirp

\(y = y_{0} + A \sin\left(\phi_{0} + 2\pi \left(f_{0}\, x + \frac{1}{2} c\, x^{2}\right)\right)\)

../../_images/step.svg

Step

\(y = y_{0}+A \left\{\begin{array}{ll}1 & \text{if } x > x_{0} \\ 0 & \text{otherwise}\end{array}\right.\)

../../_images/exponential.svg

Exponential

\(y = y_{0}+A \exp\left(B \cdot x\right)\)

../../_images/logistic.svg

Logistic

\(y = y_{0} + \dfrac{A}{1 + \exp\left(-k \left(x - x_{0}\right)\right)}\)

../../_images/pulse.svg

Pulse

\(y = y_{0}+A \left\{\begin{array}{ll}1 & \text{if } x_{0} < x < x_{1} \\ 0 & \text{otherwise}\end{array}\right.\)

../../_images/step_pulse.svg

Step Pulse

\(y = \left( \begin{cases} y_0 & \text{if } x < t_0 \\ y_0 + A \cdot \dfrac{x - t_0}{t_r} & \text{if } t_0 \leq x < t_0 + t_r \\ y_0 + A & \text{if } x \geq t_0 + t_r \end{cases} \right) + \mathcal{N}\left(0, \sigma_n\right)\)
where:
  • \(t_0\) is the pulse start time,

  • \(t_r\) is the rise time,

  • \(\sigma_n\) is the noise amplitude

../../_images/square_pulse.svg

Square Pulse

\(y(x) = \left(\begin{cases} y_0 & \text{if } x < t_0 \\ y_0 + A \cdot \dfrac{x - t_0}{t_r} & \text{if } t_0 \leq x < t_0 + t_r \\ y_0 + A & \text{if } t_0 + t_r \leq x < t_1 \\ y_0 + A - A \cdot \dfrac{x - t_1}{t_f} & \text{if } t_1 \leq x < t_1 + t_f \\ y_0 & \text{if } x \geq t_1 + t_f \end{cases} \right) + \mathcal{N}(0, \sigma_n)\)
where:
  • \(t_0\) is the pulse start time,

  • \(t_r\) is the rise time,

  • \(t_f\) is the fall time,

  • \(t_1 = t_0 + t_r + d\) is the time at which the decay starts,

  • \(\sigma_n\) is the noise amplitude

  • the duration of the plateau \(d\) is computed as \(d = t_{\mathrm{FWHM}} - \dfrac{t_r + t_f}{2}\) from the full width at half maximum \(t_{\mathrm{FWHM}}\)

Warning

The duration of the plateau \(d\) should not be negative.

../../_images/polynomial.svg

Polynomial

\(y = y_{0}+A_{0}+A_{1} \cdot x+A_{2} \cdot x^2+\ldots+A_{n} \cdot x^n\)

Custom

Manual input of X and Y values