diff --git a/src/barchart/barchartitem.cpp b/src/barchart/barchartitem.cpp
index 1131801..87a5627 100644
--- a/src/barchart/barchartitem.cpp
+++ b/src/barchart/barchartitem.cpp
@@ -122,7 +122,7 @@ QVector<QRectF> BarChartItem::calculateLayout()
         for (int set = 0; set < setCount; set++) {
             QBarSet* barSet = m_series->d_func()->barsetAt(set);
 
-            qreal barHeight = barSet->valueAt(category) * scale;
+            qreal barHeight = barSet->at(category) * scale;
             Bar* bar = m_bars.at(itemIndex);
 
             QRectF rect(xPos, yPos - barHeight, barWidth, barHeight);
@@ -132,8 +132,8 @@ QVector<QRectF> BarChartItem::calculateLayout()
 
             BarLabel* label = m_labels.at(itemIndex);
 
-            if (!qFuzzyIsNull(barSet->valueAt(category))) {
-                label->setText(QString::number(barSet->valueAt(category)));
+            if (!qFuzzyIsNull(barSet->at(category))) {
+                label->setText(QString::number(barSet->at(category)));
             } else {
                 label->setText(QString(""));
             }
diff --git a/src/barchart/barchartmodel.cpp b/src/barchart/barchartmodel.cpp
index d6a42a5..538c679 100644
--- a/src/barchart/barchartmodel.cpp
+++ b/src/barchart/barchartmodel.cpp
@@ -93,7 +93,7 @@ qreal BarChartModel::min() const
     for (int i = 0; i < m_dataModel.count(); i++) {
         int itemCount = m_dataModel.at(i)->count();
         for (int j = 0; j < itemCount; j++) {
-            qreal temp = m_dataModel.at(i)->valueAt(j);
+            qreal temp = m_dataModel.at(i)->at(j);
             if (temp < min)
                 min = temp;
         }
@@ -111,7 +111,7 @@ qreal BarChartModel::max() const
     for (int i = 0; i < m_dataModel.count(); i++) {
         int itemCount = m_dataModel.at(i)->count();
         for (int j = 0; j < itemCount; j++) {
-            qreal temp = m_dataModel.at(i)->valueAt(j);
+            qreal temp = m_dataModel.at(i)->at(j);
             if (temp > max)
                 max = temp;
         }
@@ -130,7 +130,7 @@ qreal BarChartModel::valueAt(int set, int category) const
         return 0;
     }
 
-    return m_dataModel.at(set)->valueAt(category);
+    return m_dataModel.at(set)->at(category);
 }
 
 qreal BarChartModel::percentageAt(int set, int category) const
@@ -143,7 +143,7 @@ qreal BarChartModel::percentageAt(int set, int category) const
         return 0;
     }
 
-    qreal value = m_dataModel.at(set)->valueAt(category);
+    qreal value = m_dataModel.at(set)->at(category);
     qreal total = categorySum(category);
     if ( qFuzzyCompare(total, 0) )
         return 0;
@@ -158,7 +158,7 @@ qreal BarChartModel::categorySum(int category) const
 
     for (int set = 0; set < count; set++) {
         if (category < m_dataModel.at(set)->count())
-            sum += m_dataModel.at(set)->valueAt(category);
+            sum += m_dataModel.at(set)->at(category);
     }
     return sum;
 }
@@ -170,7 +170,7 @@ qreal BarChartModel::absoluteCategorySum(int category) const
 
     for (int set = 0; set < count; set++) {
         if (category < m_dataModel.at(set)->count())
-            sum += qAbs(m_dataModel.at(set)->valueAt(category));
+            sum += qAbs(m_dataModel.at(set)->at(category));
     }
     return sum;
 }
diff --git a/src/barchart/percentbarchartitem.cpp b/src/barchart/percentbarchartitem.cpp
index 540adeb..3b3061c 100644
--- a/src/barchart/percentbarchartitem.cpp
+++ b/src/barchart/percentbarchartitem.cpp
@@ -55,7 +55,7 @@ QVector<QRectF> PercentBarChartItem::calculateLayout()
         qreal yPos = height + domainScale * m_domainMinY + geometry().topLeft().y();
         for (int set=0; set < m_series->barsetCount(); set++) {
             QBarSet* barSet = m_series->d_func()->barsetAt(set);
-            qreal barHeight = barSet->valueAt(category) * percentage * domainScale;
+            qreal barHeight = barSet->at(category) * percentage * domainScale;
             Bar* bar = m_bars.at(itemIndex);
             bar->setPen(barSet->pen());
             bar->setBrush(barSet->brush());
diff --git a/src/barchart/qbarseries.cpp b/src/barchart/qbarseries.cpp
index 1e9361a..f299cde 100644
--- a/src/barchart/qbarseries.cpp
+++ b/src/barchart/qbarseries.cpp
@@ -387,13 +387,13 @@ void QBarSeriesPrivate::modelUpdated(QModelIndex topLeft, QModelIndex bottomRigh
     {
         // model update is relevant to BarSeries if the change was made to the part of the model that was mapped to BarSeries
         if (topLeft.column() >= m_mapBarBottom && topLeft.column() <= m_mapBarTop)
-            barsetAt(topLeft.column() - m_mapBarBottom)->setValue(topLeft.row(), m_model->data(topLeft, Qt::DisplayRole).toDouble());
+            barsetAt(topLeft.column() - m_mapBarBottom)->replace(topLeft.row(), m_model->data(topLeft, Qt::DisplayRole).toDouble());
     }
     else
     {
         // model update is relevant to BarSeries if the change was made to the part of the model that was mapped to BarSeries
         if (topLeft.row() >= m_mapBarBottom && topLeft.row() <= m_mapBarTop)
-            barsetAt(topLeft.row() - m_mapBarBottom)->setValue(topLeft.column(), m_model->data(topLeft, Qt::DisplayRole).toDouble());
+            barsetAt(topLeft.row() - m_mapBarBottom)->replace(topLeft.column(), m_model->data(topLeft, Qt::DisplayRole).toDouble());
     }
 }
 
diff --git a/src/barchart/qbarset.cpp b/src/barchart/qbarset.cpp
index ff979fa..f90f532 100644
--- a/src/barchart/qbarset.cpp
+++ b/src/barchart/qbarset.cpp
@@ -60,7 +60,7 @@ QTCOMMERCIALCHART_BEGIN_NAMESPACE
 /*!
     Constructs QBarSet with a name of \a name and with parent of \a parent
 */
-QBarSet::QBarSet(QString name, QObject *parent)
+QBarSet::QBarSet(const QString name, QObject *parent)
     : QObject(parent)
     ,d_ptr(new QBarSetPrivate(name,this))
 {
@@ -77,7 +77,7 @@ QBarSet::~QBarSet()
 /*!
     Sets new \a name for set.
 */
-void QBarSet::setName(QString name)
+void QBarSet::setName(const QString name)
 {
     d_ptr->m_name = name;
 }
@@ -93,55 +93,71 @@ QString QBarSet::name() const
 /*!
     Appends new value \a value to the end of set.
 */
-QBarSet& QBarSet::operator << (const qreal &value)
+void QBarSet::append(const qreal value)
 {
     d_ptr->m_values.append(value);
     emit d_ptr->structureChanged();
+}
+
+/*!
+    Appends new value \a value to the end of set.
+*/
+QBarSet& QBarSet::operator << (const qreal &value)
+{
+    append(value);
     return *this;
 }
 
 /*!
-    Inserts new \a value on the \a i position.
-    The value that is currently at this postion is moved to postion i + 1
-    \sa removeValue()
+    Inserts new \a value on the \a index position.
+    The value that is currently at this postion is moved to postion index + 1
+    \sa remove()
 */
-void QBarSet::insertValue(int i, qreal value)
+void QBarSet::insert(const int index, const qreal value)
 {
-    d_ptr->m_values.insert(i, value);
+    d_ptr->m_values.insert(index, value);
 }
 
 /*!
-    Removes the value specified by \a i
-    \sa insertValue()
+    Removes the value specified by \a index
+    \sa insert()
 */
-void QBarSet::removeValue(int i)
+void QBarSet::remove(const int index)
 {
-    d_ptr->m_values.removeAt(i);
+    d_ptr->m_values.removeAt(index);
 }
 
 /*!
-    Returns count of values in set.
+    Sets a new value \a value to set, indexed by \a index
 */
-int QBarSet::count() const
+void QBarSet::replace(const int index, const qreal value)
 {
-    return d_ptr->m_values.count();
+    d_ptr->m_values.replace(index,value);
+    emit d_ptr->valueChanged();
 }
 
 /*!
     Returns value of set indexed by \a index
 */
-qreal QBarSet::valueAt(int index) const
+qreal QBarSet::at(const int index) const
 {
     return d_ptr->m_values.at(index);
 }
 
 /*!
-    Sets a new value \a value to set, indexed by \a index
+    Returns value of set indexed by \a index
 */
-void QBarSet::setValue(int index, qreal value)
+qreal QBarSet::operator [] (int index) const
 {
-    d_ptr->m_values.replace(index,value);
-    emit d_ptr->valueChanged();
+    return d_ptr->m_values.at(index);
+}
+
+/*!
+    Returns count of values in set.
+*/
+int QBarSet::count() const
+{
+    return d_ptr->m_values.count();
 }
 
 /*!
@@ -274,7 +290,7 @@ bool QBarSet::labelsVisible() const
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-QBarSetPrivate::QBarSetPrivate(QString name, QBarSet *parent) : QObject(parent),
+QBarSetPrivate::QBarSetPrivate(const QString name, QBarSet *parent) : QObject(parent),
     q_ptr(parent),
     m_name(name),
     m_labelsVisible(false)
diff --git a/src/barchart/qbarset.h b/src/barchart/qbarset.h
index fc83a8a..8aa3f25 100644
--- a/src/barchart/qbarset.h
+++ b/src/barchart/qbarset.h
@@ -34,18 +34,20 @@ class QTCOMMERCIALCHART_EXPORT QBarSet : public QObject
     Q_OBJECT
 
 public:
-    explicit QBarSet(QString name, QObject *parent = 0);
+    explicit QBarSet(const QString name, QObject *parent = 0);
     virtual ~QBarSet();
 
-    void setName(QString name);
+    void setName(const QString name);
     QString name() const;
-    QBarSet& operator << (const qreal &value);  // appends new value to set
-    void insertValue(int i, qreal value);
-    void removeValue(int i);
-    int count() const;                          // count of values in set
-    qreal valueAt(int index) const;             // for modifying individual values
-    void setValue(int index, qreal value);      // setter for individual value
-    qreal sum() const;                          // sum of all values in the set
+    void append(const qreal value);
+    QBarSet& operator << (const qreal &value);
+    void insert(const int index, const qreal value);
+    void remove(const int index);
+    void replace(const int index, const qreal value);
+    qreal at(const int index) const;
+    qreal operator [] (int index) const;
+    int count() const;
+    qreal sum() const;
 
     void setPen(const QPen &pen);
     QPen pen() const;
diff --git a/src/barchart/qbarset_p.h b/src/barchart/qbarset_p.h
index 3f051f8..36999ac 100644
--- a/src/barchart/qbarset_p.h
+++ b/src/barchart/qbarset_p.h
@@ -10,7 +10,7 @@ class QBarSetPrivate : public QObject
     Q_OBJECT
 
 public:
-    QBarSetPrivate(QString name, QBarSet *parent);
+    QBarSetPrivate(const QString name, QBarSet *parent);
     ~QBarSetPrivate();
 
 Q_SIGNALS:
diff --git a/src/barchart/stackedbarchartitem.cpp b/src/barchart/stackedbarchartitem.cpp
index 7a5a345..e4192ee 100644
--- a/src/barchart/stackedbarchartitem.cpp
+++ b/src/barchart/stackedbarchartitem.cpp
@@ -53,7 +53,7 @@ QVector<QRectF> StackedBarChartItem::calculateLayout()
         for (int set=0; set < m_series->barsetCount(); set++) {
             QBarSet* barSet = m_series->d_func()->barsetAt(set);
 
-            qreal barHeight = barSet->valueAt(category) * scale;
+            qreal barHeight = barSet->at(category) * scale;
             Bar* bar = m_bars.at(itemIndex);
             bar->setPen(barSet->pen());
             bar->setBrush(barSet->brush());
@@ -62,8 +62,8 @@ QVector<QRectF> StackedBarChartItem::calculateLayout()
 
             BarLabel* label = m_labels.at(itemIndex);
 
-            if (!qFuzzyIsNull(barSet->valueAt(category))) {
-                label->setText(QString::number(barSet->valueAt(category)));
+            if (!qFuzzyIsNull(barSet->at(category))) {
+                label->setText(QString::number(barSet->at(category)));
             } else {
                 label->setText(QString(""));
             }