Skip to main content

LinePlot

Namespace: DISPLIB  ·  Library: Display Library

#include <disp/lineplot.h>

class DISPLIB::LinePlot

Simple x / y line-series QWidget rendered with QPainter (no Qt Charts dependency).

Supports multiple series, a settable title and x / y labels and auto-ranging axes. Series are stored as QVector<double> pairs and re-drawn during paintEvent.

src/examples/ex_disp_plots/main.cpp
QVector<double> x;
QVector<double> y;
for (int i = 0; i <= 100; ++i) {
    x.append(i / 100.0);
    y.append(std::sin(2.0 * M_PI * x.last()));
}
LinePlot line(x, y, "sin(2 pi t)");
line.setXLabel("t [s]");
line.setYLabel("amplitude");

Inheritance​

Public Methods​

LinePlot(parent)​

Constructs a line series plot.

Parameters:

  • parent : *QWidget ** If parent is nullptr, the new widget becomes a window.

LinePlot(y, title, parent)​

Constructs a line series plot.

Parameters:

  • y : const QVector< double > & The double data vector.

  • title : const QString & Plot title.

  • parent : *QWidget ** If parent is nullptr, the new widget becomes a window.

LinePlot(x, y, title, parent)​

Constructs a line series plot.

Parameters:

  • x : const QVector< double > & X-Axis data to plot.

  • y : const QVector< double > & Y-Axis data to plot.

  • title : const QString & Plot title.

  • parent : *QWidget ** If parent is nullptr, the new widget becomes a window.

~LinePlot()​

Destructs the line series plot.

setTitle(p_sTitle)​

Sets the plot title.

Parameters:

  • p_sTitle : const QString & The title.

setXLabel(p_sXLabel)​

Sets the label of the x axis.

Parameters:

  • p_sXLabel : const QString & The x axis label.

setYLabel(p_sYLabel)​

Sets the label of the y axis.

Parameters:

  • p_sYLabel : const QString & The y axis label.

updateData(y)​

Updates the plot using a given double vector without given X data.

Parameters:

  • y : const QVector< double > & The double data vector.

updateData(x, y)​

Updates the plot using the given vectors.

Parameters:

  • x : const QVector< double > & X-Axis data to plot.

  • y : const QVector< double > & Y-Axis data to plot.

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 150
LinePlot line(x, y, "sin(2 pi t)");
line.setXLabel("t [s]");
line.setYLabel("amplitude");
const QImage lineImage = render(line);
int top = lineImage.height();
int bottom = 0;
for (int py = 0; py < lineImage.height(); ++py) {
    for (int px = 0; px < lineImage.width(); ++px) {
        if (close(lineImage.pixel(px, py), steelBlue, 40)) {
            top = std::min(top, py);
            bottom = std::max(bottom, py);
        }
    }

Authors of this file​