Curve demo 1

import sys
import numpy as np

from qwt.qt.QtGui import (QApplication, QPen, QBrush, QFrame, QFont, QPainter,
                          QPaintEngine)
from qwt.qt.QtCore import QSize
from qwt.qt.QtCore import Qt
from qwt import QwtSymbol, QwtPlotCurve, QwtPlotItem, QwtScaleMap


class CurveDemo(QFrame):
    def __init__(self, *args):
        QFrame.__init__(self, *args)

        self.xMap = QwtScaleMap()
        self.xMap.setScaleInterval(-0.5, 10.5)
        self.yMap = QwtScaleMap()
        self.yMap.setScaleInterval(-1.1, 1.1)

        # frame style
        self.setFrameStyle(QFrame.Box | QFrame.Raised)
        self.setLineWidth(2)
        self.setMidLineWidth(3)

        # calculate values
        self.x = np.arange(0, 10.0, 10.0/27)
        self.y = np.sin(self.x)*np.cos(2*self.x)
        
        # make curves with different styles
        self.curves = []
        self.titles = []
        # curve 1
        self.titles.append('Style: Sticks, Symbol: Ellipse')
        curve = QwtPlotCurve()
        curve.setPen(QPen(Qt.red))
        curve.setStyle(QwtPlotCurve.Sticks)
        curve.setSymbol(QwtSymbol(QwtSymbol.Ellipse,
                                      QBrush(Qt.yellow),
                                      QPen(Qt.blue),
                                      QSize(5, 5)))
        self.curves.append(curve)
        # curve 2
        self.titles.append('Style: Lines, Symbol: None')
        curve = QwtPlotCurve()
        curve.setPen(QPen(Qt.darkBlue))
        curve.setStyle(QwtPlotCurve.Lines)
        self.curves.append(curve)
        # curve 3
        self.titles.append('Style: Lines, Symbol: None, Antialiased')
        curve = QwtPlotCurve()
        curve.setPen(QPen(Qt.darkBlue))
        curve.setStyle(QwtPlotCurve.Lines)
        curve.setRenderHint(QwtPlotItem.RenderAntialiased)
        self.curves.append(curve)
        # curve 4
        self.titles.append('Style: Steps, Symbol: None')
        curve = QwtPlotCurve()
        curve.setPen(QPen(Qt.darkCyan))
        curve.setStyle(QwtPlotCurve.Steps)
        self.curves.append(curve)        
        # curve 5
        self.titles.append('Style: NoCurve, Symbol: XCross')
        curve = QwtPlotCurve()
        curve.setStyle(QwtPlotCurve.NoCurve)
        curve.setSymbol(QwtSymbol(QwtSymbol.XCross,
                                      QBrush(),
                                      QPen(Qt.darkMagenta),
                                      QSize(5, 5)))
        self.curves.append(curve)

        # attach data, using Numeric
        for curve in self.curves:
            curve.setData(self.x, self.y)

    def shiftDown(self, rect, offset):
        rect.translate(0, offset)

    def paintEvent(self, event):
        QFrame.paintEvent(self, event)
        painter = QPainter(self)
        painter.setClipRect(self.contentsRect())
        self.drawContents(painter)

    def drawContents(self, painter):
        # draw curves
        r = self.contentsRect()
        dy = r.height()/len(self.curves)
        r.setHeight(dy)
        for curve in self.curves:
            self.xMap.setPaintInterval(r.left(), r.right())
            self.yMap.setPaintInterval(r.top(), r.bottom())
            engine = painter.device().paintEngine()
            if engine is not None and engine.hasFeature(QPaintEngine.Antialiasing):
                painter.setRenderHint(
                    QPainter.Antialiasing,
                    curve.testRenderHint(QwtPlotItem.RenderAntialiased))
            curve.draw(painter, self.xMap, self.yMap, r)
            self.shiftDown(r, dy)
        # draw titles
        r = self.contentsRect()
        r.setHeight(dy)
        painter.setFont(QFont('Helvetica', 8))
        painter.setPen(Qt.black)
        for title in self.titles:
            painter.drawText(
                0, r.top(), r.width(), painter.fontMetrics().height(),
                Qt.AlignTop | Qt.AlignHCenter, title)
            self.shiftDown(r, dy)


def make():
    demo = CurveDemo()
    demo.resize(300, 600)
    demo.show()
    return demo


if __name__ == '__main__':
    app = QApplication(sys.argv)
    demo = make()
    sys.exit(app.exec_())