sidMapPlot

Python equivalent: sid.map_plot

Time-frequency color map for sidFreqMap results.

sidMapPlot(result)
sidMapPlot(result, 'PlotType', 'coherence')
h = sidMapPlot(...)

Plots the time-varying frequency response as a color map, with time on the x-axis and frequency on the y-axis.

Inputs

Name	Description
result	FreqMapResult struct (see sidResultTypes §2). Required fields: .Time, .Frequency, .FrequencyHz, .SampleTime, .NoiseSpectrum Depending on PlotType: .Response, .Coherence

Name-value options

Name	Description
'PlotType'	What to plot: 'magnitude' (default) - 20log10(|G(w,t)|) in dB 'phase' - angle(G(w,t)) in degrees 'noise' - 10log10(\(Phi_v(w,t)\)) in dB 'coherence' - gamma^2(w,t) on [0, 1] 'spectrum' - 10*log10(\(Phi_y(w,t)\)) for time series
'FrequencyUnit'	'rad/s' (default) or 'Hz'.
'CLim'	Color axis limits [cmin cmax]. Default: [] (auto).
'Axes'	Axes handle. Creates new figure if empty.

Outputs

Name	Description
h	Struct with fields .fig, .ax, .surf.

Examples

% Time-varying magnitude map
N = 4000; u = randn(N, 1);
y = filter([1], [1 -0.9], u) + 0.1*randn(N, 1);
result = sidFreqMap(y, u, 'SegmentLength', 512);
sidMapPlot(result, 'PlotType', 'magnitude');

Specification

SPEC.md §6.9 — Visualization: sidMapPlot

See also

sidFreqMap, sidSpectrogramPlot, sidBodePlot

Changelog

• 2026-03-28: First version by Pedro Lourenço.