diff --git a/examples/jkqtfastplotter_test/jkqtfastplotter_test_testmain.cpp b/examples/jkqtfastplotter_test/jkqtfastplotter_test_testmain.cpp
index 85a3e0cb1e..e3da432b15 100644
--- a/examples/jkqtfastplotter_test/jkqtfastplotter_test_testmain.cpp
+++ b/examples/jkqtfastplotter_test/jkqtfastplotter_test_testmain.cpp
@@ -120,8 +120,8 @@ TestMain::TestMain(QWidget *parent) :
     gl->addWidget(p21, 0, 0, 1, 3);
     for (int x=0; x<IMAGE_N; x++) {
         for (int y=0; y<IMAGE_N; y++) {
-            imageRed[y*IMAGE_N+x]=(fabs(x)+fabs(y))/2.0;
-            imageGreen[y*IMAGE_N+x]=(fabs(double(IMAGE_N)-x)+fabs(y))/2.0;
+            imageRed[y*IMAGE_N+x]=static_cast<double>(std::abs(x)+std::abs(y))/2.0;
+            imageGreen[y*IMAGE_N+x]=(fabs(double(IMAGE_N)-x)+static_cast<double>(std::abs(y)))/2.0;
             imageBlue[y*IMAGE_N+x]=sqrt(x*x+y*y);
         }
     }
diff --git a/examples/jkqtplot_test/TestWidgetBarcharts.cpp b/examples/jkqtplot_test/TestWidgetBarcharts.cpp
index 884f28628f..e7506e7d1c 100644
--- a/examples/jkqtplot_test/TestWidgetBarcharts.cpp
+++ b/examples/jkqtplot_test/TestWidgetBarcharts.cpp
@@ -112,7 +112,7 @@ TestWidgetBarcharts::TestWidgetBarcharts(QWidget *parent) :
 
     spinBarLabelAngel=new QSpinBox(this);
     spinBarLabelAngel->setPrefix(tr("rotation angel:  "));
-    spinBarLabelAngel->setSuffix(QLatin1String("°"));
+    spinBarLabelAngel->setSuffix(QLatin1String("\xB0"));
     spinBarLabelAngel->setRange(-180,180);
     spinBarLabelAngel->setValue(0);
     spinBarLabelAngel->setSingleStep(15);
@@ -121,7 +121,7 @@ TestWidgetBarcharts::TestWidgetBarcharts(QWidget *parent) :
 
     spinBarLabelAngel2=new QSpinBox(this);
     spinBarLabelAngel2->setPrefix(tr("rotation angel:  "));
-    spinBarLabelAngel2->setSuffix(QLatin1String("°"));
+    spinBarLabelAngel2->setSuffix(QLatin1String("\xB0"));
     spinBarLabelAngel2->setRange(-180,180);
     spinBarLabelAngel2->setValue(0);
     spinBarLabelAngel2->setSingleStep(15);
diff --git a/lib/jkqtcommon/jkqtpstathistogram.h b/lib/jkqtcommon/jkqtpstathistogram.h
index af6e48efca..9a0b1c1608 100644
--- a/lib/jkqtcommon/jkqtpstathistogram.h
+++ b/lib/jkqtcommon/jkqtpstathistogram.h
@@ -223,7 +223,7 @@ inline void jkqtpstatHistogram1D(InputIt first, InputIt last, BinsInputIt binsFi
         const double v=jkqtp_todouble(*it);
         if (JKQTPIsOKFloat(v)) {
             auto itb=std::lower_bound(histX.begin(), histX.end(), v);
-            size_t bin=jkqtp_bounded<size_t>(0,static_cast<size_t>(abs(std::distance(histX.begin(), itb))), histY.size()-1);
+            size_t bin=jkqtp_bounded<size_t>(0,static_cast<size_t>(std::abs(std::distance(histX.begin(), itb))), histY.size()-1);
             histY[bin]++;
         }
     }
diff --git a/lib/jkqtplotter/graphs/jkqtpboxplotstylingmixins.cpp b/lib/jkqtplotter/graphs/jkqtpboxplotstylingmixins.cpp
index 505b5926f4..cba3d240cf 100644
--- a/lib/jkqtplotter/graphs/jkqtpboxplotstylingmixins.cpp
+++ b/lib/jkqtplotter/graphs/jkqtpboxplotstylingmixins.cpp
@@ -754,7 +754,7 @@ void JKQTPGraphBoxplotStyleMixin::plotVerticalKeyMarker(JKQTBasePlotter *parent,
     const double min=rect.bottom();
     const double max=rect.top();
     const double median=max+rect.height()/2.0;
-    const double w=abs(xma-xmi);
+    const double w=fabs(xma-xmi);
     const double p25=max+0.75*rect.height();
     const double p75=max+0.25*rect.height();
 
diff --git a/lib/jkqtplotter/graphs/jkqtpcontour.cpp b/lib/jkqtplotter/graphs/jkqtpcontour.cpp
index 04b04d6776..8ff404dfaf 100644
--- a/lib/jkqtplotter/graphs/jkqtpcontour.cpp
+++ b/lib/jkqtplotter/graphs/jkqtpcontour.cpp
@@ -428,7 +428,6 @@ void JKQTPContourPlot::calcContourLines(QList<QVector<QLineF> > &ContourLines)
 JKQTPColumnContourPlot::JKQTPColumnContourPlot(JKQTBasePlotter *parent):
     JKQTPContourPlot(parent)
 {
-    this->imageColumn=imageColumn;
     this->datatype=JKQTPMathImageDataType::DoubleArray;
 }
 
diff --git a/lib/jkqtplotter/jkqtpdatastorage.h b/lib/jkqtplotter/jkqtpdatastorage.h
index 02e829ba0c..0f989fa5c6 100644
--- a/lib/jkqtplotter/jkqtpdatastorage.h
+++ b/lib/jkqtplotter/jkqtpdatastorage.h
@@ -804,7 +804,7 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPDatastore{
          */
         template <typename TIterator>
         size_t addCopiedColumn(TIterator first, TIterator last, const QString& name=QString("")) {
-            const size_t N=static_cast<size_t>(abs(std::distance(first,last)));
+            const size_t N=static_cast<size_t>(std::abs(std::distance(first,last)));
             double* d=static_cast<double*>(malloc(static_cast<size_t>(N)*sizeof(double)));
             if (N>0) {
                 size_t r=0;
@@ -1121,7 +1121,7 @@ class JKQTPLOTTER_LIB_EXPORT JKQTPDatastore{
          */
        template <typename TIterator>
         std::pair<size_t, size_t> addCopiedMap(TIterator first, TIterator last, const QString& nameKey=QString("map_key"), const QString& nameValue=QString("map_value")) {
-            const size_t N=static_cast<size_t>(abs(std::distance(first,last)));
+            const size_t N=static_cast<size_t>(std::abs(std::distance(first,last)));
             double* xvals=static_cast<double*>(malloc(N*sizeof(double)));
             double* yvals=static_cast<double*>(malloc(N*sizeof(double)));
             size_t i=0;