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ImageSc

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

#include <disp/imagesc.h>

class DISPLIB::ImageSc

False-colour heat-map QWidget visualising an Eigen matrix with selectable colour map.

Accepts MatrixXd, MatrixXf and MatrixXi inputs; init() rebuilds the cached QImage from the current matrix and the active colour map, and updateData() / paintEvent() keep the rendering in sync with the data.

src/examples/ex_disp_plots/main.cpp
MatrixXd ramp(4, 8);
for (int r = 0; r < ramp.rows(); ++r) {
    for (int c = 0; c < ramp.cols(); ++c) {
        ramp(r, c) = c; // rises left to right
    }
}
ImageSc image(ramp); // min..max mapped to 0..1, "Hot" by default
image.setColorMap("Viridis");
image.setTitle("ramp");
image.setExtent(0.0, 0.7, 4.0, 1.0); // columns at 0 .. 0.7 s, rows 1 .. 4 from the top
image.setXLabel("Time [s]");
image.setYLabel("Trial");
image.setColorbarLabel("Value");

Inheritance​

Public Methods​

ImageSc(parent)​

Creates the scaled image view.

Parameters:

  • parent : *QWidget ** Parent QObject (optional).

ImageSc(p_dMat, parent)​

Creates the scaled image view with a given double matrix.

Parameters:

  • p_dMat : Eigen::MatrixXd & The double data matrix.

  • parent : *QWidget ** Parent QObject (optional).

ImageSc(p_fMat, parent)​

Creates the scaled image view with a given float matrix.

Parameters:

  • p_fMat : Eigen::MatrixXf & The float data matrix.

  • parent : *QWidget ** Parent QObject (optional).

ImageSc(p_iMat, parent)​

Creates the scaled image view with a given integer matrix.

Parameters:

  • p_iMat : Eigen::MatrixXi & The integer data matrix.

  • parent : *QWidget ** Parent QObject (optional).

~ImageSc()​

Destructs the ImageSc object.

init()​

Initializes the ImageSc object.

updateData(p_dMat)​

Updates the scaled image view with a given double matrix.

Parameters:

  • p_dMat : Eigen::MatrixXd & The double data matrix.

updateData(p_fMat)​

Updates the scaled image view with a given float matrix.

Parameters:

  • p_fMat : Eigen::MatrixXf & The float data matrix.

updateData(p_iMat)​

Updates the scaled image view with a given integer matrix.

Parameters:

  • p_iMat : Eigen::MatrixXi & The integer data matrix.

setColorMap(p_sColorMap)​

Sets the color map to use, e.g.

"Jet", "Hot", "Bone"

Parameters:

  • p_sColorMap : const QString & The colormap to use.

setExtent(left, right, bottom, top)​

Labels the axes in data units instead of column and row indices, as matplotlib's imshow(extent=...).

Parameters:

  • left : double X value of the first column.

  • right : double X value of the last column.

  • bottom : double Y value of the last row, drawn at the bottom.

  • top : double Y value of the first row, drawn at the top.

setColorRange(min, max)​

Maps min and max to the ends of the colour map instead of the data minimum and maximum; values outside are clipped.

A range symmetric around zero centres diverging maps such as "RedBlue".

Parameters:

  • min : double Value drawn with the low end of the colour map.

  • max : double Value drawn with the high end of the colour map.

setColorbarLabel(label)​

Names the quantity the colour bar shows, e.g.

"Power (normalized)".

Parameters:

  • label : const QString & The colour bar label; empty hides it.

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 179
ImageSc image(ramp); // min..max mapped to 0..1, "Hot" by default
image.setColorMap("Viridis");
image.setTitle("ramp");
image.setExtent(0.0, 0.7, 4.0, 1.0); // columns at 0 .. 0.7 s, rows 1 .. 4 from the top
image.setXLabel("Time [s]");
image.setYLabel("Trial");
image.setColorbarLabel("Value");
const QImage scImage = render(image);
// Along the middle row the first viridis-dark pixel sits left of the first viridis-yellow pixel
int darkX = -1;
int brightX = -1;
for (int px = 0; px < scImage.width(); ++px) {
    if (darkX < 0 && close(scImage.pixel(px, 150), qRgb(68, 1, 84), 4)) {

ex_disp​

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

src/examples/ex_disp/main.cpp, line 211
const double limit = gradData.cwiseAbs().maxCoeff();
ImageSc imagesc(gradData);
imagesc.setTitle(QString("%1 gradiometers").arg(grads.size()));
imagesc.setXLabel("Time [s]");
imagesc.setYLabel("Gradiometer");
imagesc.setColorbarLabel("fT/cm");
imagesc.setColorMap("RedBlue"); // also "Jet", "Hot", "Bone", "Viridis"
imagesc.setColorRange(-limit, limit);
imagesc.setExtent(times(0, 0), times(0, times.cols() - 1), grads.size(), 1);

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 111
DISPLIB::Plot* m_pEvokedSignalCoursePlot = nullptr;
DISPLIB::Plot* m_pEpochSignalCoursePlot = nullptr;
DISPLIB::Plot* m_pEvokedSourceSignalCoursePlot = nullptr;
DISPLIB::ImageSc* m_pImageConnWeights = nullptr;

Also used in ex_connectivity_metrics, ex_dsp_spectral, ex_read_epochs.

Authors of this file​