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TFplot

Namespace: DISPLIB  ·  Library: Display Library  ·  Source: disp/plots/tfplot.h

#include <disp/tfplot.h>

class DISPLIB::TFplot

Time-frequency power image of a spectrogram: time in seconds, frequency in Hz, normalized power.

Row k of the spectrogram is the FFT bin at k * sample_rate / N Hz, where N, the number of columns, is the FFT length; column j is the time tmin + j / sample_rate s.

src/examples/ex_disp_plots/main.cpp
MatrixXd tf = MatrixXd::Zero(50, 100);  // 100 samples at 100 Hz: 50 frequency rows of 1 Hz x 100 times
tf.middleRows(20, 10).setConstant(1.0); // power in the 20-29 Hz bins
TFplot tfPlot(tf, 100.0, 0.0, 50.0, Jet);

Inheritance​

Public Methods​

TFplot(tf_matrix, sample_rate, lower_frq, upper_frq, cmap, tmin)​

Plots the frequency bins from lower_frq to upper_frq.

Parameters:

  • tf_matrix : const Eigen::MatrixXd & Spectrogram power, N/2 frequency bins x N time samples.

  • sample_rate : qreal Sample rate of the signal in Hz.

  • lower_frq : qreal Lowest frequency to plot in Hz.

  • upper_frq : qreal Highest frequency to plot in Hz.

  • cmap : ColorMaps Colour map.

  • tmin : qreal Time of the first sample in s, e.g. the start of an epoch.

TFplot(tf_matrix, sample_rate, cmap, tmin)​

Plots all frequency bins.

Parameters:

  • tf_matrix : const Eigen::MatrixXd & Spectrogram power, N/2 frequency bins x N time samples.

  • sample_rate : qreal Sample rate of the signal in Hz.

  • cmap : ColorMaps Colour map.

  • tmin : qreal Time of the first sample in s, e.g. the start of an epoch.

Example​

Used in examples​

ex_disp_plots​

Disp plots: colour maps, bar and spline histograms, line plots, image and time-frequency maps.

src/examples/ex_disp_plots/main.cpp, line 212
MatrixXd tf = MatrixXd::Zero(50, 100);  // 100 samples at 100 Hz: 50 frequency rows of 1 Hz x 100 times
tf.middleRows(20, 10).setConstant(1.0); // power in the 20-29 Hz bins
TFplot tfPlot(tf, 100.0, 0.0, 50.0, Jet);
const QImage tfImage = render(tfPlot);
ok &= expect(countColor(tfImage, ColorMap::valueToJet(1.0), 10) > 100 && countColor(tfImage, ColorMap::valueToJet(0.0), 10) > countColor(tfImage, ColorMap::valueToJet(1.0), 10),
             "TFplot draws the 20-30 Hz band in the top colour over a bottom-colour background");

ex_disp​

Disp library widgets: image map, line plot and time-frequency plot of raw data.

src/examples/ex_disp/main.cpp, line 230
//tf plot example: spectrogram of the same channel
MatrixXd dataSpectrum = Spectrogram::makeSpectrogram(dataCol, raw.info.sfreq * 0.2);
TFplot tfplot(dataSpectrum, raw.info.sfreq, 0, 100, ColorMaps::Jet, times(0, 0));

ex_connectivity​

Sensor- or source-level functional connectivity of averaged MEG/EEG data with a selectable metric, shown as a 3D network.

src/examples/ex_connectivity/connectivitysettingsmanager.h, line 116
TFplot::SPtr m_pTfPlot;
Eigen::MatrixXd m_matEvoked;
Eigen::MatrixXd m_matEvokedSource;
MNELIB::MNEEpochDataList epochs;

Also used in ex_tf_plot.

Authors of this file​