implemented wiggle plots (feature request #68)

doc/dox/examples_and_tutorials.dox

@@ -35,9 +35,12 @@ All test-projects are Qt-projects that use qmake to build. You can load them int
 <tr><td> \image html JKQTPBarHorizontalGraphStacked_small.png
     <td> \subpage JKQTPlotterStackedBarChart
     <td> `JKQTPBarVerticalStackableGraph`, `JKQTPBarHorizontalStackableGraph` <br> C++-style vectors of data 
-<tr><td> \image html filledgraphs_small.png
-    <td> \subpage JKQTPlotterFilledGraphs
-    <td> `JKQTPBarVerticalGraph` <br> setting/altering data in `JKQTPDatstore` directly <br>  transparent plots <br> calculating histograms 
+<tr><td> \image html filledgraphs_small.png
+    <td> \subpage JKQTPlotterFilledGraphs
+    <td> `JKQTPFilledCurveXGraph`/`JKQTPFilledCurveYGraph` <br> setting/altering data in `JKQTPDatstore` directly <br>  transparent plots <br> calculating histograms 
+<tr><td> \image html wiggleplots_small.png
+    <td> \subpage JKQTPlotterWigglePlots
+    <td> `JKQTPFilledCurveXGraph`/`JKQTPFilledCurveYGraph` <br> setting/altering data in `JKQTPDatstore` directly <br>  data-depentend coloring <br> random-walks <br> seismographic data
 <tr><td> \image html impulsesplot_small.png
     <td> \subpage JKQTPlotterImpulsePlots
     <td> `JKQTPImpulsesVerticalGraph` and `JKQTPImpulsesHorizontalGraph` <br> C++-style QVector as plot data 

doc/dox/whatsnew.dox

@@ -14,7 +14,7 @@ This page lists release notes for the diferent version of JKQTPlotter
 \subsection page_whatsnew_TRUNK_OVERVIEW trunk: Overview
 Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
 <ul>
-   <li></li>
+   <li>JKQTPFilledCurveXGraph and JKQTPFilledCurveYGraph can now plot wiggle plots with different fill styles above and below the baseline (feature request <a href="https://github.com/jkriege2/JKQtPlotter/issues/68">#68 Wiggle Plots</a> from <a href="https://github.com/xichaoqiang">user:xichaoqiang</a>   </li>
 </ul>
 
 \subsection page_whatsnew_TRUNK_DOWNLOAD trunk: Download

examples/CMakeLists.txt

@@ -60,5 +60,5 @@ add_subdirectory(symbols_and_styles)
 add_subdirectory(ui)
 add_subdirectory(user_interaction)
 add_subdirectory(violinplot)
-
+add_subdirectory(wiggleplots)
 

examples/README.md

@@ -15,7 +15,8 @@ All test-projects are Qt-projects that use qmake to build. You can load them int
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/errorbarstyles_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/errorbarstyles) | [Different Types of Error Indicators](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/errorbarstyles) | `JKQTPXYLineErrorGraph` <br> different styles of error indicators for x- and y-errors <br> C++-style QVector for data <br> styling error indicators <br> moving key and formatting plotter grid |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/barchart_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/barchart) | [Simple Bar Charts](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/barchart) | `JKQTPBarVerticalGraph` <br> C-style arrays of data |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/JKQTPbarHorizontalGraphStacked_small.png) <br> ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/JKQTPbarVerticalGraphStacked_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/stackedbars) | [Stacked Bar Charts](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/stackedbars) | `JKQTPBarVerticalStackableGraph`, `JKQTPBarHorizontalStackableGraph` <br> C++-style vectors of data |
-| [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/filledgraphs_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/filledgraphs) | [Filled Curve Plots](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/filledgraphs) | `JKQTPBarVerticalGraph` <br> setting/altering data in `JKQTPDatstore` directly <br>  transparent plots <br> calculating histograms |
+| [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/filledgraphs_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/filledgraphs) | [Filled Curve Plots](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/filledgraphs) | `JKQTPFilledCurveXGraph`/`JKQTPFilledCurveYGraph` <br> setting/altering data in `JKQTPDatstore` directly <br>  transparent plots <br> calculating histograms |
+| [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/wiggleplots_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/wiggleplots) | [Wiggle Plots](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/wiggleplots) | `JKQTPFilledCurveXGraph`/`JKQTPFilledCurveYGraph` <br> setting/altering data in `JKQTPDatstore` directly <br> data-dependent coloring <br> random-walks <br> seismographic data |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/impulsesplot_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/impulsesplot) | [Impulse Plots](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/impulsesplot) | `JKQTPImpulsesVerticalGraph` and `JKQTPImpulsesHorizontalGraph` <br> C++-style QVector as plot data |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/paramscatterplot_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/paramscatterplot) | [Scatter Graph with Parametrized Symbols/Colors](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/paramscatterplot) | `JKQTPXYParametrizedScatterGraph` <br> C++-style QVector as plot data <br> modify scatter/points/line-graph properties by data |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/paramscatterplot_image_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/paramscatterplot_image) | [Draw an Artistic Image with a Parametrized Scatter Graph](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/paramscatterplot_image) | `JKQTPXYParametrizedScatterGraph` <br> C++-style QVector as plot data <br> rectangular arrangement of scatters <br> generative computer graphics |

examples/wiggleplots/CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.16)
+
+set(EXAMPLE_NAME wiggleplots)
+set(EXENAME jkqtptest_${EXAMPLE_NAME})
+
+message( STATUS "..   Building Example ${EXAMPLE_NAME}" )
+
+
+# Set up source files
+set(SOURCES ${EXAMPLE_NAME}.cpp)
+set(HEADERS )
+set(RESOURCES )
+set(UIS  )
+
+add_executable(${EXENAME} WIN32 ${SOURCES} ${HEADERS} ${RESOURCES} ${UIS})
+target_include_directories(${EXENAME} PRIVATE ../../lib)
+if(JKQtPlotter_BUILD_STATIC_LIBS)
+    target_link_libraries(${EXENAME} JKQTPlotterLib)
+elseif(JKQtPlotter_BUILD_SHARED_LIBS)
+    target_link_libraries(${EXENAME} JKQTPlotterSharedLib)
+endif()
+
+
+
+# Installation
+install(TARGETS ${EXENAME} RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+
+#Installation of Qt DLLs on Windows
+jkqtplotter_deployqt(${EXENAME})

examples/wiggleplots/README.md

@@ -0,0 +1,149 @@
+# Example (JKQTPlotter): Wiggle Plots {#JKQTPlotterWigglePlots}
+
+This project (see `./examples/wiggleplots/`) demonstrates how to draw "wiggle plots" with JKQtPlotter, using `JKQTPFilledCurveXGraph` or `JKQTPFilledCurveYGraph`. Wiggle plots are plots, where the fill color is different above and below the baseline of the plot. They are e.g. used in seismology.
+
+The source code of the main application can be found in  [`wiggleplots.cpp`](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/wiggleplots/wiggleplots.cpp). If creates two different plots that demonstrate two styles of plots and also uses the horizontal and vertical variant of the graph class.
+
+## Plot red/blue wiggle plot using `JKQTPFilledCurveXGraph`
+
+For the first example we simulate a 1D random walk and plot the result as a filles wiggle plot:
+
+In a first step, we obtain a pointer to the JKQTPDatastore and add two columns to it.
+```.cpp
+    // 1. get a pointer to the internal datastore (for convenience)
+    JKQTPDatastore* ds=plot.getDatastore();
+
+    // 2. now we create 2 datacolumns with length 1000 (NSteps) entries in the datastore
+    //    these will later hold the time-step and position of a random walker
+    const size_t NSteps=400;
+    const size_t columnT=ds->addLinearColumn(NSteps, 0, NSteps-1, "time");
+    const size_t columnX=ds->addColumn(NSteps, "position");
+```
+
+Now we fill the column with the random walk data:
+
+```.cpp
+    // 3. now we simulate a simple rendom walk and store the calculated positions
+    //    in columnX
+    double pos=5;
+    const double stepsize=1;
+    std::random_device rd; // random number generators:
+    std::mt19937 gen{rd()};
+    std::uniform_int_distribution<int> dist(0,1);
+
+    for (size_t t=0; t<NSteps; t++) {
+        ds->set(columnX, t, pos);
+        pos=pos+stepsize*(static_cast<double>(dist(gen))*2.0-1.0);
+    }
+```
+
+Now we can generate the actual graph and set its basic properties and data columns:
+
+```.cpp
+    // 4. now we add three semi-transparent, filled curve plots, one for each histogram
+    JKQTPFilledCurveXGraph* graph=new JKQTPFilledCurveXGraph(&plot);
+
+    // 5. set graph titles
+    graph->setTitle("Random Walk");
+
+    // 6. set data
+    graph->setXColumn(columnT); graph->setYColumn(columnX);
+```
+
+Now we can acrivate the wiggle plot style filling mode and set the fill colors and line color and width.
+
+```.cpp
+    // 7.1 enable wiggle-plot filling
+    graph->setFillMode(JKQTPFilledCurveXGraph::TwoColorFilling);
+    // 7.2 draw the data also as a black, thin line
+    graph->setLineColor(QColor("black"));
+    graph->setLineWidth(1);
+    // 7.3 fill areas below the baseline with red
+    graph->setFillColor(QColor("red"));
+    // 7.4 fill areas above the baseline with blue
+    graph->fillStyleBelow().setFillColor(QColor("blue"));
+```
+
+The baseline is set to the starting point (5) of the random walk. By default it would be at y=0.
+
+```.cpp
+    // 7.5 set the baseline to be at 5 (not the default 0
+    graph->setBaseline(5);
+```
+
+Now we only have to add the graph to the plotter and set some final properties for styling:
+
+```.cpp
+    // 8. add the graphs to the plot, so they are actually displayed
+    plot.addGraph(graph);
+
+    // 9. set axis labels
+    plot.getXAxis()->setAxisLabel("time $t$");
+    plot.getYAxis()->setAxisLabel("walker position $x(t)$");
+
+    // 10. scale plot automatically
+    plot.zoomToFit();
+
+    // 11. show plotter and make it a decent size
+    plot.show();
+    plot.resize(600,400);
+```
+
+This is the resulting plot:
+
+![wiggleplot of random walk](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/wiggleplot_x.png)
+
+
+## Plot black/transparent wiggle plot using `JKQTPFilledCurveYGraph` in a "seismographic style"
+
+The second example follows mor or less the same steps as above, but here we add several graphs that each show a wavepacket that is shoft slightly:
+
+```.cpp
+    // 3. now we calculate several wavepackets and add a graph for each.
+    const size_t NWavepackets=7;
+    for (size_t nw=0; nw<NWavepackets; nw++) {
+        const size_t columnPacket=ds->addColumn(NSteps, "wavepacket1");
+
+        const double packwidth=0.4/static_cast<double>(NWavepackets);
+        const double pos=pow(static_cast<double>(nw), 0.6)*packwidth*3.5+5.0*packwidth;
+        const double wavelength=packwidth/1.5;
+        const double offset=(static_cast<double>(nw)*1.5+1.5);
+        for (size_t ti=0; ti<NSteps; ti++) {
+            const double t=ds->get(columnT, ti);
+            ds->set(columnPacket, ti, offset+sin(2.0*M_PI*t/wavelength)*exp(-0.5*jkqtp_sqr(t-pos)/jkqtp_sqr(packwidth)));
+        }
+
+
+        // 4. now we add three semi-transparent, filled curve plots, one for each histogram
+        JKQTPFilledCurveYGraph* graph=new JKQTPFilledCurveYGraph(&plot);
+
+        // set graph titles
+        graph->setTitle("wave "+QString::number(nw+1));
+
+        // set data
+        graph->setYColumn(columnT); graph->setXColumn(columnPacket);
+
+        // enable wiggle-plot filling
+        graph->setFillMode(JKQTPFilledCurveXGraph::TwoColorFilling);
+        // draw the data also as a black, thin line
+        graph->setLineColor(QColor("black"));
+        graph->setLineWidth(1);
+        // fill areas below the baseline with red
+        graph->setFillColor(Qt::transparent);
+        // fill areas above the baseline with blue
+        graph->fillStyleBelow().setFillColor(QColor("black"));
+        // set the baseline to be at 5 (not the default 0
+        graph->setBaseline(offset);
+
+
+        // add the graphs to the plot, so they are actually displayed
+        plot.addGraph(graph);
+    }
+```
+
+Also the colors are different: We use black below the baseline and transparent above. The line through the data points is black as well.
+
+
+This is the resulting plot:
+
+![wiggleplot of random walk](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/wiggleplot_y.png)

examples/wiggleplots/wiggleplots.cpp

@@ -0,0 +1,155 @@
+/** \example wiggleplots.cpp
+ * Shows how to use filled graphs with JKQTPlotter
+ *
+ * \ref JKQTPlotterwiggleplots
+ */
+
+#include <QApplication>
+#include "jkqtplotter/jkqtplotter.h"
+#include "jkqtplotter/graphs/jkqtpfilledcurve.h"
+#include <random>
+
+void drawRandomWalkX(JKQTPlotter& plot) {
+
+    // 1. get a pointer to the internal datastore (for convenience)
+    JKQTPDatastore* ds=plot.getDatastore();
+
+    // 2. now we create 2 datacolumns with length 1000 (NSteps) entries in the datastore
+    //    these will later hold the time-step and position of a random walker
+    const size_t NSteps=400;
+    const size_t columnT=ds->addLinearColumn(NSteps, 0, NSteps-1, "time");
+    const size_t columnX=ds->addColumn(NSteps, "position");
+
+    // 3. now we simulate a simple rendom walk and store the calculated positions
+    //    in columnX
+    double pos=5;
+    const double stepsize=1;
+    std::random_device rd; // random number generators:
+    std::mt19937 gen{rd()};
+    std::uniform_int_distribution<int> dist(0,1);
+
+    for (size_t t=0; t<NSteps; t++) {
+        ds->set(columnX, t, pos);
+        pos=pos+stepsize*(static_cast<double>(dist(gen))*2.0-1.0);
+    }
+
+
+    // 4. now we add three semi-transparent, filled curve plots, one for each histogram
+    JKQTPFilledCurveXGraph* graph=new JKQTPFilledCurveXGraph(&plot);
+
+    // 5. set graph titles
+    graph->setTitle("Random Walk");
+
+    // 6. set data
+    graph->setXColumn(columnT); graph->setYColumn(columnX);
+
+    // 7.1 enable wiggle-plot filling
+    graph->setFillMode(JKQTPFilledCurveXGraph::TwoColorFilling);
+    // 7.2 draw the data also as a black, thin line
+    graph->setLineColor(QColor("black"));
+    graph->setLineWidth(1);
+    // 7.3 fill areas below the baseline with red
+    graph->setFillColor(QColor("red"));
+    // 7.4 fill areas above the baseline with blue
+    graph->fillStyleBelow().setFillColor(QColor("blue"));
+    // 7.5 set the baseline to be at 5 (not the default 0
+    graph->setBaseline(5);
+
+
+    // 8. add the graphs to the plot, so they are actually displayed
+    plot.addGraph(graph);
+
+    // 9. set axis labels
+    plot.getXAxis()->setAxisLabel("time $t$");
+    plot.getYAxis()->setAxisLabel("walker position $x(t)$");
+
+
+    // 10. scale plot automatically
+    plot.zoomToFit();
+
+    // 11. show plotter and make it a decent size
+    plot.show();
+    plot.resize(600,400);
+}
+
+void drawWavepacketsY(JKQTPlotter& plot) {
+
+    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
+    JKQTPDatastore* ds=plot.getDatastore();
+
+    // 2. now we create a datacolumns with length 1200 (NSteps) entries in the datastore
+    //    these will later hold the time-value for each wavepacket
+    const size_t NSteps=1200;
+    const size_t columnT=ds->addLinearColumn(NSteps, 0, 1, "time");
+
+
+    // 3. now we calculate several wavepackets and add a graph for each.
+    const size_t NWavepackets=7;
+    for (size_t nw=0; nw<NWavepackets; nw++) {
+        const size_t columnPacket=ds->addColumn(NSteps, "wavepacket1");
+
+        const double packwidth=0.4/static_cast<double>(NWavepackets);
+        const double pos=pow(static_cast<double>(nw), 0.6)*packwidth*3.5+5.0*packwidth;
+        const double wavelength=packwidth/1.5;
+        const double offset=(static_cast<double>(nw)*1.5+1.5);
+        for (size_t ti=0; ti<NSteps; ti++) {
+            const double t=ds->get(columnT, ti);
+            ds->set(columnPacket, ti, offset+sin(2.0*M_PI*t/wavelength)*exp(-0.5*jkqtp_sqr(t-pos)/jkqtp_sqr(packwidth)));
+        }
+
+
+        // 4. now we add three semi-transparent, filled curve plots, one for each histogram
+        JKQTPFilledCurveYGraph* graph=new JKQTPFilledCurveYGraph(&plot);
+
+        // set graph titles
+        graph->setTitle("wave "+QString::number(nw+1));
+
+        // set data
+        graph->setYColumn(columnT); graph->setXColumn(columnPacket);
+
+        // enable wiggle-plot filling
+        graph->setFillMode(JKQTPFilledCurveXGraph::TwoColorFilling);
+        // draw the data also as a black, thin line
+        graph->setLineColor(QColor("black"));
+        graph->setLineWidth(1);
+        // fill areas below the baseline with red
+        graph->setFillColor(Qt::transparent);
+        // fill areas above the baseline with blue
+        graph->fillStyleBelow().setFillColor(QColor("black"));
+        // set the baseline to be at 5 (not the default 0
+        graph->setBaseline(offset);
+
+
+        // add the graphs to the plot, so they are actually displayed
+        plot.addGraph(graph);
+    }
+
+    // 5. set axis labels
+    plot.getXAxis()->setAxisLabel("wavepacket amplitude $f(t)$");
+    plot.getYAxis()->setAxisLabel("time $t$");
+
+
+    // 4. scale plot automatically
+    plot.zoomToFit();
+
+    // 5. show plotter and make it a decent size
+    plot.show();
+    plot.resize(600,600);
+}
+
+int main(int argc, char* argv[])
+{
+        
+#if QT_VERSION >= QT_VERSION_CHECK(5,6,0) &&  QT_VERSION < QT_VERSION_CHECK(6,0,0)
+
+    QApplication::setAttribute(Qt::AA_EnableHighDpiScaling); // DPI support
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps); //HiDPI pixmaps
+#endif
+    QApplication app(argc, argv);
+
+    JKQTPlotter plotWalk, plotWavepackets;
+    drawRandomWalkX(plotWalk);
+    drawWavepacketsY(plotWavepackets);
+
+    return app.exec();
+}

examples/wiggleplots/wiggleplots.pro

@@ -0,0 +1,30 @@
+# source code for this simple demo
+SOURCES = wiggleplots.cpp 
+
+RESOURCES += 
+
+# configure Qt
+CONFIG += link_prl qt
+QT += core gui xml  svg
+greaterThan(QT_MAJOR_VERSION, 4): QT += widgets printsupport
+
+# output executable name
+TARGET = wiggleplots
+
+
+# include JKQTPlotter source code
+DEPENDPATH += ../../lib  ../../qmake/staticlib/jkqtplotterlib
+INCLUDEPATH += ../../lib
+CONFIG (debug, debug|release) {
+    LIBS += -L../../qmake/staticlib/jkqtplotterlib/debug -ljkqtplotterlib_debug
+} else {
+    LIBS += -L../../qmake/staticlib/jkqtplotterlib/release -ljkqtplotterlib
+}
+message("LIBS = $$LIBS")
+
+win32-msvc*: DEFINES += _USE_MATH_DEFINES
+win32-msvc*: DEFINES += NOMINMAX
+
+
+
+

examples/wiggleplots/wiggleplots_and_lib.pro

@@ -0,0 +1,8 @@
+TEMPLATE = subdirs
+
+SUBDIRS +=  jkqtplotterlib wiggleplots
+
+jkqtplotterlib.file = ../../qmake/staticlib/jkqtplotterlib/jkqtplotterlib.pro
+
+wiggleplots.file=$$PWD/wiggleplots.pro
+wiggleplots.depends = jkqtplotterlib

lib/jkqtplotter/graphs/jkqtpfilledcurve.cpp

@@ -33,11 +33,12 @@
 
 
 JKQTPFilledCurveGraphBase::JKQTPFilledCurveGraphBase(JKQTBasePlotter *parent):
-    JKQTPXYBaselineGraph(parent)
+    JKQTPXYBaselineGraph(parent), m_fillMode(FillMode::SingleFilling)
 {
     parentPlotStyle=-1;
     initLineStyle(parent, parentPlotStyle, JKQTPPlotStyleType::Filled);
     initFillStyle(parent, parentPlotStyle, JKQTPPlotStyleType::Filled);
+    m_fillStyleBelow.initFillStyleInvertedColor(this);
     setFillCurve(true);
     setDrawLine(true);
 }
@@ -57,16 +58,50 @@ void JKQTPFilledCurveGraphBase::drawKeyMarker(JKQTPEnhancedPainter &painter, QRe
     painter.setPen(np);
     if (getDrawLine()) painter.setPen(p);
     painter.setBrush(b);
-    if (getFillCurve()) painter.drawRect(rect);
+    if (getFillCurve()) {
+        if (getFillMode()==FillMode::SingleFilling) {
+            painter.drawRect(rect);
+        } else {
+            QBrush belowB=fillStyleBelow().getFillBrush(painter, parent);
+            QPolygonF p,pb;
+            p<<rect.topLeft()<<rect.topRight()<<rect.bottomRight();
+            pb<<rect.topLeft()<<rect.bottomRight()<<rect.bottomLeft();
+            painter.drawPolygon(p);
+            painter.setBrush(belowB);
+            painter.drawPolygon(pb);
+            painter.setBrush(b);
+        }
+    }
     if (!getFillCurve() && getDrawLine()) painter.drawLine(QLineF(rect.left(), y, rect.right(), y));
 }
 
+JKQTPGraphFillStyleMixin &JKQTPFilledCurveGraphBase::fillStyleBelow()
+{
+    return m_fillStyleBelow;
+}
+
+const JKQTPGraphFillStyleMixin &JKQTPFilledCurveGraphBase::fillStyleBelow() const
+{
+    return m_fillStyleBelow;
+}
+
+JKQTPFilledCurveGraphBase::FillMode JKQTPFilledCurveGraphBase::getFillMode() const
+{
+    return m_fillMode;
+}
+
 void JKQTPFilledCurveGraphBase::setColor(QColor c)
 {
     setLineColor(c);
     setFillColor(JKQTPGetDerivedColor(parent->getCurrentPlotterStyle().graphsStyle.filledStyle.fillColorDerivationMode, c));
     c.setAlphaF(0.5);
     setHighlightingLineColor(c);
+    m_fillStyleBelow.initFillStyleInvertedColor(this);
+}
+
+void JKQTPFilledCurveGraphBase::setFillMode(FillMode mode)
+{
+    m_fillMode=mode;
 }
 
 
@@ -98,6 +133,7 @@ void JKQTPFilledCurveXGraph::draw(JKQTPEnhancedPainter& painter) {
     QPen ph=getHighlightingLinePen(painter, parent);
     QPen np(Qt::NoPen);
     QBrush b=getFillBrush(painter, parent);
+    QBrush b_below=fillStyleBelow().getFillBrush(painter, parent);
 
     int imax=0;
     int imin=0;
@@ -150,7 +186,22 @@ void JKQTPFilledCurveXGraph::draw(JKQTPEnhancedPainter& painter) {
         auto __finalpaint=JKQTPFinally([&painter]() {painter.restore();});
 
         if (getFillCurve()) {
-            painter.fillPath(pf, b);
+            if (getFillMode()==FillMode::SingleFilling) {
+                painter.fillPath(pf, b);
+            } else if (getFillMode()==FillMode::TwoColorFilling) {
+                QRectF rAbove=pf.boundingRect();
+                rAbove.setBottom(y0);
+                QPainterPath pAbove;
+                pAbove.addRect(rAbove);
+                QRectF rBelow=pf.boundingRect();
+                rBelow.setTop(y0);
+                QPainterPath pBelow;
+                pBelow.addRect(rBelow);
+                QPainterPath pfa=pf.intersected(pAbove);
+                QPainterPath pfb=pf.intersected(pBelow);
+                painter.fillPath(pfa, b);
+                painter.fillPath(pfb, b_below);
+            }
         }
 
         if (isHighlighted()) {
@@ -196,6 +247,7 @@ void JKQTPFilledCurveYGraph::draw(JKQTPEnhancedPainter &painter)
     QPen ph=getHighlightingLinePen(painter, parent);
     QPen np(Qt::NoPen);
     QBrush b=getFillBrush(painter, parent);
+    QBrush b_below=fillStyleBelow().getFillBrush(painter, parent);
 
     int imax=0;
     int imin=0;
@@ -245,7 +297,22 @@ void JKQTPFilledCurveYGraph::draw(JKQTPEnhancedPainter &painter)
         painter.save(); auto __finalpaint=JKQTPFinally([&painter]() {painter.restore();});
 
         if (getFillCurve()) {
-            painter.fillPath(pf, b);
+            if (getFillMode()==FillMode::SingleFilling) {
+                painter.fillPath(pf, b);
+            } else if (getFillMode()==FillMode::TwoColorFilling) {
+                QRectF rAbove=pf.boundingRect();
+                rAbove.setLeft(x0);
+                QPainterPath pAbove;
+                pAbove.addRect(rAbove);
+                QRectF rBelow=pf.boundingRect();
+                rBelow.setRight(x0);
+                QPainterPath pBelow;
+                pBelow.addRect(rBelow);
+                QPainterPath pfa=pf.intersected(pAbove);
+                QPainterPath pfb=pf.intersected(pBelow);
+                painter.fillPath(pfa, b);
+                painter.fillPath(pfb, b_below);
+            }
         }
 
         if (isHighlighted()) {

lib/jkqtplotter/graphs/jkqtpfilledcurve.h

@@ -40,6 +40,16 @@
 class JKQTPLOTTER_LIB_EXPORT JKQTPFilledCurveGraphBase: public JKQTPXYBaselineGraph, public JKQTPGraphLineAndFillStyleMixin {
     Q_OBJECT
 public:
+    /** \brief specifies how the area below the graph is filled
+     *
+     *  \see setFillMode(), getFillMode(), fillStyleBelow(), \ref JKQTPlotterWigglePlots
+     */
+    enum FillMode {
+        SingleFilling=0, /*!< \brief the whole area is filled with the same color/pattern, generates "simple filled plots", such as \image html filledgraphs_small.png */
+        TwoColorFilling=1 /*!< \brief the area above and below baseline with the two different colors/patterns, generates "wiggle plots", such as \image html wiggleplots_small.png */
+    };
+    Q_ENUM(FillMode)
+
     /** \brief class constructor */
     explicit JKQTPFilledCurveGraphBase(JKQTBasePlotter* parent=nullptr);
 
@@ -47,12 +57,23 @@ public:
     virtual QColor getKeyLabelColor() const override;
     /** \brief plots a key marker inside the specified rectangle \a rect */
     virtual void drawKeyMarker(JKQTPEnhancedPainter& painter, QRectF& rect) override;
-
+    /** \copydoc m_fillStyleBelow */
+    JKQTPGraphFillStyleMixin& fillStyleBelow();
+    /** \copydoc m_fillStyleBelow */
+    const JKQTPGraphFillStyleMixin& fillStyleBelow() const;
+    /** \copydoc m_fillMode */
+    FillMode getFillMode() const;
 public slots:
     /** \brief set line-color, fill color and symbol color */
     void setColor(QColor c);
+    /** \copydoc m_fillMode */
+    void setFillMode(FillMode mode);
 protected:
-
+    /** \brief specifies how the area of the graph is filles */
+    FillMode m_fillMode;
+    /** \brief if m_fillMode \c ==FillAboveAndBelowDifferently then this fill style is used below the baseline and
+     *         the default fill style is used above */
+    JKQTPGraphFillStyleMixin m_fillStyleBelow;
 };
 
 
@@ -63,6 +84,19 @@ protected:
     \image html filledgraphs.png
 
     \see \ref JKQTPlotterFilledGraphs
+
+    This class also provides the possibility to file above and below the baseline with different style.
+    Such plots are sometimes called "Wiggle Plots" and are often used (in their black/white-variety for seismographic
+    data plotting.
+
+    \image html wiggleplot_x.png
+
+    To generate such a plot, used \c JKQTPFilledCurveXGraph::setFillMode(JKQTPFilledCurveXGraph::FillMode::TwoColorFilling)
+    and then use \c JKQTPFilledCurveXGraph::fillStyleBelow() to access the fill style for the area below the baseline
+    and the default fill style to define the fill style above the baseline.
+
+    \see \ref JKQTPlotterWigglePlots
+
  */
 class JKQTPLOTTER_LIB_EXPORT JKQTPFilledCurveXGraph: public JKQTPFilledCurveGraphBase {
         Q_OBJECT
@@ -113,6 +147,18 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPFilledCurveXErrorGraph: public JKQTPFilledCurv
 
     \see \ref JKQTPlotterFilledGraphs
 
+    This class also provides the possibility to file above and below the baseline with different style.
+    Such plots are sometimes called "Wiggle Plots" and are often used (in their black/white-variety for seismographic
+    data plotting.
+
+    \image html wiggleplot_x.png
+
+    To generate such a plot, used \c JKQTPFilledCurveXGraph::setFillMode(JKQTPFilledCurveXGraph::FillMode::TwoColorFilling)
+    and then use \c JKQTPFilledCurveXGraph::fillStyleBelow() to access the fill style for the area below the baseline
+    and the default fill style to define the fill style above the baseline.
+
+    \see \ref JKQTPlotterWigglePlots
+
  */
 class JKQTPLOTTER_LIB_EXPORT JKQTPFilledCurveYGraph: public JKQTPFilledCurveGraphBase {
         Q_OBJECT

lib/jkqtplotter/jkqtpgraphsbasestylingmixins.cpp

@@ -288,6 +288,19 @@ JKQTPGraphFillStyleMixin::JKQTPGraphFillStyleMixin()
 }
 
 
+void JKQTPGraphFillStyleMixin::initFillStyleInvertedColor(JKQTPGraphFillStyleMixin *other)
+{
+    if (other) { // get style settings from parent object
+        m_fillColor=other->getFillColor();
+        qreal h=0,s=0,v=0,a=0;
+        m_fillColor.getHsvF(&h, &s, &v, &a);
+        h=std::fmod(h+120.0/360.0, 1.0);
+        m_fillColor.setHsvF(h,s,v,a);
+        m_fillBrush.setColor(m_fillColor);
+        m_fillBrush.setStyle(other->getFillStyle());
+    }
+}
+
 void JKQTPGraphFillStyleMixin::initFillStyle(JKQTBasePlotter *parent, int &parentPlotStyle, JKQTPPlotStyleType styletype)
 {
     if (parent) { // get style settings from parent object

lib/jkqtplotter/jkqtpgraphsbasestylingmixins.h

@@ -400,6 +400,8 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPGraphFillStyleMixin {
 
         /** \brief initiaize the fill style (from the parent plotter) */
         void initFillStyle(JKQTBasePlotter* parent, int &parentPlotStyle, JKQTPPlotStyleType styletype=JKQTPPlotStyleType::Default);
+        /** \brief initiaize the fill style from another JKQTPGraphFillStyleMixin \a other by inverting its fill color */
+        void initFillStyleInvertedColor(JKQTPGraphFillStyleMixin *other);
 
         virtual ~JKQTPGraphFillStyleMixin();
 
@@ -434,14 +436,15 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPGraphFillStyleMixin {
 
         Q_PROPERTY(Qt::BrushStyle fillStyle MEMBER m_fillStyle READ getFillStyle WRITE setFillStyle)
         Q_PROPERTY(QColor fillColor MEMBER m_fillColor READ getFillColor WRITE setFillColor)
+
+        /** \brief constructs a QBrush from the graph fill styling properties */
+        QBrush getFillBrush(JKQTPEnhancedPainter &painter, JKQTBasePlotter* parent) const;
     private:
         /** \brief fill style of the graph */
         QBrush m_fillBrush;
         /** \brief last fill color of the graph  */
         QColor m_fillColor;
     protected:
-        /** \brief constructs a QBrush from the graph fill styling properties */
-        QBrush getFillBrush(JKQTPEnhancedPainter &painter, JKQTBasePlotter* parent) const;
 };