improved data-access via JKQTPcolumn

added example for filled curves and data-access via JKQTPcolumn

JKQtPlotterBuildAllExamples.pro

@@ -42,6 +42,7 @@ addSimpleTest(logaxes)
 addSimpleTest(stackedbars)
 addSimpleTest(symbols_and_errors)
 addSimpleTest(symbols_and_styles)
+addSimpleTest(filledgraphs)
 addSimpleTest(speed)
 addSimpleTest(rgbimageplot_qt)
 #addSimpleTest(imageplot_nodatastore)

README.md

@@ -25,6 +25,7 @@ All test-projects are Qt-projects that use qmake to build. You can load them int
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/jkqtplotter_simpletest_errorbarstyles_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_errorbarstyles) | [Different Types of Error Indicators](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_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/jkqtplotter_simpletest_barchart_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_barchart) | [Simple Bar Charts](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_barchart) | `JKQTPbarVerticalGraph`<br/>C-style arrays of data |
 | [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/JKQTPbarVerticalGraphStacked_small.png)<br>![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/JKQTPbarHorizontalGraphStacked_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_stackedbars) | [Stacked Bar Charts](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_stackedbars) | `JKQTPbarVerticalStackableGraph`, `JKQTPbarHorizontalStackableGraph`<br/>C++-style vectors of data |
+| [![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/jkqtplotter_simpletest_filledgraphs_small.png)](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_filledgraphs) | [Filled Curve Plots](https://github.com/jkriege2/JKQtPlotter/tree/master/test/simpletest_filledgraphs) | `JKQTPbarVerticalGraph`<br/>setting/altering data in `JKQTPdatstore` directly<br/> transparent plots<br/>calculating histograms |
 
 ### Styling the Plot, Keys, Axes, ...
 

lib/jkqtplotter/jkqtpdatastorage.cpp

@@ -86,13 +86,6 @@ QVector<double> JKQTPcolumn::copyData()
     return d;
 }
 
-////////////////////////////////////////////////////////////////////////////////////////////////
-double JKQTPcolumn::getValue(size_t n) const
-{
-    if (!datastore) return 0;
-    if (!datastore->getItem(datastoreItem)) return 0;
-    return datastore->getItem(datastoreItem)->get(datastoreOffset, n);
-}
 
 ////////////////////////////////////////////////////////////////////////////////////////////////
 double *JKQTPcolumn::getPointer(size_t n) const
@@ -102,15 +95,6 @@ double *JKQTPcolumn::getPointer(size_t n) const
     return datastore->getItem(datastoreItem)->getPointer(datastoreOffset, n);
 }
 
-////////////////////////////////////////////////////////////////////////////////////////////////
-void JKQTPcolumn::setValue(size_t n, double val)
-{
-    if (!datastore) return ;
-    if (!datastore->getItem(datastoreItem)) return ;
-    datastore->getItem(datastoreItem)->set(datastoreOffset, n, val);
-}
-
-
 
 ////////////////////////////////////////////////////////////////////////////////////////////////
 void JKQTPcolumn::copy(double* data, size_t N, size_t offset) {
@@ -159,6 +143,19 @@ void JKQTPcolumn::scale(double factor)
     }
 }
 
+////////////////////////////////////////////////////////////////////////////////////////////////
+void JKQTPcolumn::setAll(double value)
+{
+    if (!datastore) return ;
+    double* data=getPointer();
+    size_t N=getRows();
+    if (data){
+        for (size_t i=0; i<N; i++) {
+            data[i]=value;
+        }
+    }
+}
+
 
 /**************************************************************************************************************************
  * JKQTPdatastoreItem

lib/jkqtplotter/jkqtpdatastorage.h

@@ -627,17 +627,30 @@ class LIB_EXPORT JKQTPcolumn {
      * This method accesses the datastore and returns the double value stored in the \a n'th row of the according
      * column.
      */
-    double getValue(size_t n) const;
+    inline double getValue(size_t n) const;
     /** \brief gets a pointer to the n-th value in the column
      */
     double* getPointer(size_t n=0) const ;
 
     /** \brief sets the \a n'th value from the column
      *
-     * This method accesses the datastore and returns the double value stored in the \a n'th row of the according
+     * This method accesses the datastore and sets the value stored in the \a n'th row of the according
      * column.
      */
-    void setValue(size_t n, double val);
+    inline void setValue(size_t n, double val);
+
+    /** \brief increment the \a n'th value from the column
+     *
+     */
+    inline void incValue(size_t n, double increment=1.0);
+
+    /** \brief decrement the \a n'th value from the column
+     *
+     */
+    inline void decValue(size_t n, double decrement=1.0) {
+        incValue(n, -1.0*decrement);
+    }
+
 
     /** \brief sets the element at (x,y) in the column, where the data is interpreted as a row-major ordered Matrix of the given width
      *
@@ -658,7 +671,7 @@ class LIB_EXPORT JKQTPcolumn {
      */
     void copy(double* data, size_t N, size_t offset=0);
 
-    /** \brief exchange everz occurence of a given \a value by a \a replace value */
+    /** \brief exchange every occurence of a given \a value by a \a replace value */
     void exchange(double value, double replace);
 
     /** \brief subtracts a given value from all members of the column */
@@ -666,6 +679,9 @@ class LIB_EXPORT JKQTPcolumn {
     /** \brief scales all members of the column with the given factor */
     void scale(double factor);
 
+    /** \brief set all values in the column to a specific \a value */
+    void setAll(double value);
+
     JKQTPGET_MACRO(size_t, datastoreItem)
     JKQTPGET_MACRO(size_t, datastoreOffset)
 };
@@ -796,4 +812,28 @@ class LIB_EXPORT JKQTPdatastoreModel: public QAbstractTableModel {
 };
 
 
+
+
+
+////////////////////////////////////////////////////////////////////////////////////////////////
+inline void JKQTPcolumn::setValue(size_t n, double val){
+    if (!datastore) return ;
+    if (!datastore->getItem(datastoreItem)) return ;
+    datastore->getItem(datastoreItem)->set(datastoreOffset, n, val);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////
+inline void JKQTPcolumn::incValue(size_t n, double increment){
+    if (!datastore) return ;
+    if (!datastore->getItem(datastoreItem)) return ;
+    datastore->getItem(datastoreItem)->set(datastoreOffset, n, datastore->getItem(datastoreItem)->get(datastoreOffset, n)+increment);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////
+inline double JKQTPcolumn::getValue(size_t n) const {
+    if (!datastore) return 0;
+    if (!datastore->getItem(datastoreItem)) return 0;
+    return datastore->getItem(datastoreItem)->get(datastoreOffset, n);
+}
+
 #endif // JKQTPDATASTORAGE_H

test/simpletest_filledgraphs/README.md

@@ -0,0 +1,79 @@
+[Back to JKQTPlotter main page](https://github.com/jkriege2/JKQtPlotter/)
+
+# JKQtPlotter
+
+## Filled Curve Plots
+This project (see `./test/simpletest_filledgraphs/`) simply creates a JKQtPlotter widget (as a new window) and adds several filled curve graphs (Histograms). Data is initialized from QVector<int> objects.
+
+The source code of the main application can be found in  [`jkqtplotter_simpletest_filledgraphs.cpp`](https://github.com/jkriege2/JKQtPlotter/blob/master/test/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs.cpp). 
+
+First the data columns for three x-y-curves are generated. One column of x-values with entries 0,1,2,...,254,255 (256 entries). 
+```c++
+    size_t columnX=ds->addLinearColumn(256, 0, 255, "x");
+```
+
+And three columns with 256 entries each, which will be filled with the R-, G- and B-histograms of an image `example.bmp`:
+```c++
+    size_t columnR=ds->addColumn(256, "historam_R");
+    size_t columnG=ds->addColumn(256, "historam_G");
+    size_t columnB=ds->addColumn(256, "historam_B");
+```
+	
+In this example we will access the data in the internal datastore directly. This access is possible through objects of type JKQTPcolumn, which is a proxy to the data in one of the columns in a `JKQTdatastore`:
+```c++
+    JKQTPcolumn cG=ds->getColumn(columnG);
+    JKQTPcolumn cR=ds->getColumn(columnR);
+    JKQTPcolumn cB=ds->getColumn(columnB);
+```c++
+
+In order to calculate the histograms, first all enries in the columns are set to 0:
+```c++
+    cR.setAll(0);
+    cG.setAll(0);
+    cB.setAll(0);
+```
+Finally the histogram is calculated:
+```c++
+    QImage image(":/example.bmp");
+    for (int y=0; y<image.height(); y++) {
+        for (int x=0; x<image.width(); x++) {
+            QRgb pix=image.pixel(x,y);
+            cR.incValue(qRed(pix), 1);
+            cG.incValue(qGreen(pix), 1);
+            cB.incValue(qBlue(pix), 1);
+        }
+    }
+    cR.scale(100.0/static_cast<double>(image.width()*image.height()));
+    cG.scale(100.0/static_cast<double>(image.width()*image.height()));
+    cB.scale(100.0/static_cast<double>(image.width()*image.height()));
+```
+
+Finally three `JKQTPfilledCurveXGraph` objects are generated and added to the plot (here we show the code for the R-channel only):
+```c++
+    JKQTPfilledCurveXGraph* graphR=new JKQTPfilledCurveXGraph(&plot);
+
+    // set graph titles
+    graphR->set_title("R-channel");
+
+    // set graph colors (lines: non-transparent, fill: semi-transparent
+    QColor col;
+    col=QColor("red"); graphR->set_color(col);
+    col.setAlphaF(0.25); graphR->set_fillColor(col);
+
+    // set data
+    graphR->set_xColumn(columnX); graphR->set_yColumn(columnR);
+
+
+    // add the graphs to the plot, so they are actually displayed
+    plot.addGraph(graphR);
+```
+
+The curves are fille with a semi-transparent color, which is achieved by setting `col.setAlphaF(0.25)` on the graph color `col`.
+
+The result looks like this:
+
+![jkqtplotter_simpletest_filledgraphs](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/jkqtplotter_simpletest_filledgraphs.png)
+
+
+
+[Back to JKQTPlotter main page](https://github.com/jkriege2/JKQtPlotter/)

test/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs.cpp

@@ -0,0 +1,98 @@
+#include <QApplication>
+#include "jkqtplotter/jkqtplotter.h"
+#include "jkqtplotter/jkqtpfilledcurveelements.h"
+
+int main(int argc, char* argv[])
+{
+    QApplication app(argc, argv);
+
+    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
+    JKQtPlotter plot;
+    JKQTPdatastore* ds=plot.getDatastore();
+
+    // 2. now we create 4 datacolumns with length 256 entries in the datastore
+    //    these will later hold the RGB-histogram and a linear x-values vector
+    //      - the x-values are directly initialized as linear vector 0..255 in 256 steps
+    //      - the other columns are generated and size_t-type indexes are stored for later
+    //        reference to these columns in the graphs-
+    size_t columnX=ds->addLinearColumn(256, 0, 255, "x");
+    size_t columnR=ds->addColumn(256, "historam_R");
+    size_t columnG=ds->addColumn(256, "historam_G");
+    size_t columnB=ds->addColumn(256, "historam_B");
+    //      - in addition JKQTPcolumn objects are generated, which can be used to access
+    //        the data in the columns
+    JKQTPcolumn cG=ds->getColumn(columnG);
+    JKQTPcolumn cR=ds->getColumn(columnR);
+    JKQTPcolumn cB=ds->getColumn(columnB);
+    //      - now all columns for RGB are initialized to 0
+    cR.setAll(0);
+    cG.setAll(0);
+    cB.setAll(0);
+
+    // 3. now we open a BMP-file and load it into a QImage
+    QImage image(":/example.bmp");
+    // ... and calculate the RGB-histograms
+    for (int y=0; y<image.height(); y++) {
+        for (int x=0; x<image.width(); x++) {
+            QRgb pix=image.pixel(x,y);
+            cR.incValue(qRed(pix), 1);
+            cG.incValue(qGreen(pix), 1);
+            cB.incValue(qBlue(pix), 1);
+        }
+    }
+    // ... and normalize histograms
+    cR.scale(100.0/static_cast<double>(image.width()*image.height()));
+    cG.scale(100.0/static_cast<double>(image.width()*image.height()));
+    cB.scale(100.0/static_cast<double>(image.width()*image.height()));
+
+
+    // 4. now we add three semi-transparent, filled curve plots, one for each histogram
+    JKQTPfilledCurveXGraph* graphR=new JKQTPfilledCurveXGraph(&plot);
+    JKQTPfilledCurveXGraph* graphG=new JKQTPfilledCurveXGraph(&plot);
+    JKQTPfilledCurveXGraph* graphB=new JKQTPfilledCurveXGraph(&plot);
+
+    // set graph titles
+    graphR->set_title("R-channel");
+    graphG->set_title("G-channel");
+    graphB->set_title("B-channel");
+
+    // set graph colors (lines: non-transparent, fill: semi-transparent) and style
+    QColor col;
+    col=QColor("red"); graphR->set_color(col);
+    col.setAlphaF(0.25); graphR->set_fillColor(col);
+    col=QColor("green"); graphG->set_color(col);
+    col.setAlphaF(0.25); graphG->set_fillColor(col);
+    col=QColor("blue"); graphB->set_color(col);
+    col.setAlphaF(0.25); graphB->set_fillColor(col);
+    graphR->set_lineWidth(1);
+    graphG->set_lineWidth(1);
+    graphB->set_lineWidth(1);
+
+    // set data
+    graphR->set_xColumn(columnX); graphR->set_yColumn(columnR);
+    graphG->set_xColumn(columnX); graphG->set_yColumn(columnG);
+    graphB->set_xColumn(columnX); graphB->set_yColumn(columnB);
+
+
+    // add the graphs to the plot, so they are actually displayed
+    plot.addGraph(graphB);
+    plot.addGraph(graphG);
+    plot.addGraph(graphR);
+
+    // 5. set axis labels
+    plot.getXAxis()->set_axisLabel("R/G/B-value");
+    plot.getYAxis()->set_axisLabel("normalized frequency [%]");
+
+
+    // 4. set the maximum size of the plot to 0..100% and 0..256
+    plot.setAbsoluteX(0,256);
+    plot.setAbsoluteY(0,100);
+    // ... and scale plot automatically
+    plot.zoomToFit();
+
+    // 5. show plotter and make it a decent size
+    plot.show();
+    plot.resize(600,400);
+
+    return app.exec();
+}

test/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs.pro

@@ -0,0 +1,24 @@
+# source code for this simple demo
+SOURCES = jkqtplotter_simpletest_filledgraphs.cpp 
+
+RESOURCES += jkqtplotter_simpletest_filledgraphs.qrc
+
+# configure Qt
+CONFIG += qt
+QT += core gui xml  svg
+greaterThan(QT_MAJOR_VERSION, 4): QT += widgets printsupport
+
+# output executable name
+TARGET = jkqtplotter_simpletest_filledgraphs
+
+
+# include JKQtPlotter source code
+DEPENDPATH += . ../../lib
+INCLUDEPATH += ../../lib
+CONFIG (debug, debug|release):LIBS += -L../../lib/debug -ljkqtplotterlib
+CONFIG (release):LIBS += -L../../lib/release -ljkqtplotterlib
+
+
+# here you can activate some debug options
+#DEFINES += SHOW_JKQTPLOTTER_DEBUG
+#DEFINES += JKQTBP_AUTOTIMER

test/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs.qrc

@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/">
+        <file>example.bmp</file>
+    </qresource>
+</RCC>

test/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs_and_lib.pro

@@ -0,0 +1,8 @@
+TEMPLATE = subdirs
+
+SUBDIRS +=  jkqtplotterlib jkqtplotter_simpletest_filledgraphs
+
+jkqtplotterlib.file = ../../lib/jkqtplotterlib.pro
+
+jkqtplotter_simpletest_filledgraphs.file=$$PWD/jkqtplotter_simpletest_filledgraphs.pro
+jkqtplotter_simpletest_filledgraphs.depends = jkqtplotterlib