Design Simulation Systems Ltd

Mathematical Waveform Manipulation Tools

Vspice3 will accept data from an ASCII file or the binary file generated by SPICE as a simulation runs. This latter may be read 'live' during the simulation, or post facto. When the waveform data has been read in, the DSP functions described below may be applied to the waveforms.

All of the following waveform manipulation algorithms use double-precision complex mathematical calculation and assume complex inputs.
All arithmetic functions accept floating point numeric constants as one or other input parameter, for waveform scaling, weighting, etc

Fast Fourier Transform
Fast Fourier Transform in Real/Imaginary or Magnitude/Phase format. FFT has user-selectable zero-fill up 65536 data points and Hamming, Hanning and Blackman windows.

Inverse Fast Fourier Transform
IFT Transform in Real/Imaginary or Magnitude/Phase format

Convolution
Performs the convolution of the two waveforms selected by the mouse. Self-convolution may be performed by selecting the same waveform twice.

Deconvolution
Deconvolves the first waveform selected with the second.

Cross and Auto Correlation
Performs the correlation of the two waveforms selected by the mouse. Auto-correlation may be performed by selecting the same waveform twice.

Differentiation
Differentiates the waveform selected by the mouse, using a two-point algorithm.

Integration
Integrates the waveform selected by the mouse, using Simpson's Rule.

Performs the algebraic sum of the two waveforms selected by the mouse, analogous to additive mixing.

Subtraction
Subtracts the second waveform selected by the mouse from the first.

Multiplication
Multiplies together the two waveforms selected by the mouse, analogous to suppressed carrier modulation.

Division
Divides the first waveform selected by the mouse by the second. There is logic present to avoid divide-by-zero errors.

Inversion
Inverts the selected waveform, by multiplying each point by -1.00, in double precision arithmetic.

Real/Imaginary -> Magnitude/Phase
Will convert a real/imaginary waveform to mag/phase.

Magnitude/Phase -> Real/Imaginary
Will convert a mag/phase waveform to its real and imaginary components.

True RMS Calculation

True Mean Calculation

Complex-Plane Display