diff --git a/apps/calculation/additional_outputs/complex_graph_cell.cpp b/apps/calculation/additional_outputs/complex_graph_cell.cpp
index f00b0ed12..8538b2fe6 100644
--- a/apps/calculation/additional_outputs/complex_graph_cell.cpp
+++ b/apps/calculation/additional_outputs/complex_graph_cell.cpp
@@ -13,14 +13,16 @@ ComplexGraphView::ComplexGraphView(ComplexModel * complexModel) :
 
 void ComplexGraphView::drawRect(KDContext * ctx, KDRect rect) const {
   ctx->fillRect(rect, KDColorWhite);
+
+  // Draw grid, axes and graduations
   drawGrid(ctx, rect);
   drawAxes(ctx, rect);
-  // Draw graduations
   drawLabelsAndGraduations(ctx, rect, Axis::Vertical, true);
   drawLabelsAndGraduations(ctx, rect, Axis::Horizontal, true);
 
   float real = m_complex->real();
   float imag = m_complex->imag();
+
   /* Draw the segment from the origin to the dot (real, imag) of equation
    * x(t) = t*real and y(t) = t*imag with t in [0,1] */
   drawCurve(ctx, rect, 0.0f, 1.0f, 0.01f,
@@ -28,6 +30,7 @@ void ComplexGraphView::drawRect(KDContext * ctx, KDRect rect) const {
         ComplexModel * complexModel = (ComplexModel *)model;
         return Poincare::Coordinate2D<float>(complexModel->real()*t, complexModel->imag()*t);
       }, m_complex, nullptr, false, Palette::GreyDark, false);
+
   /* Draw the partial ellipse indicating the angle θ
    * - the ellipse parameters are a = |real|/5 and b = |imag|/5,
    * - the parametric ellipse equation is x(t) = a*cos(th*t) and y(t) = b*sin(th*t)
@@ -42,29 +45,34 @@ void ComplexGraphView::drawRect(KDContext * ctx, KDRect rect) const {
   assert(imag != 0.0f); // ComplexGraphView is not displayed for pure real
   float th = std::atan(std::fabs(real/imag)*std::tan(std::arg(*m_complex)));
   if (real < 0.0f) {
-    th += imag < 0.0f ? -M_PI : M_PI;
+    th += imag < 0.0f ? -M_PI : M_PI; // atan returns value in [-π/2,π/2]
   }
-  // Avoid flat ellipsis for edge cases (real = 0)
+  // Compute ellipsis parameters a and b
+  float factor = 5.0f;
+  float a = std::fabs(real)/factor;
+  float b = std::fabs(imag)/factor;
+  // Avoid flat ellipsis for edge cases (for real = 0, the case imag = 0 is excluded)
   if (real == 0.0f) {
+    a = 1.0f/factor;
     th = imag < 0.0f ? -M_PI/2.0f : M_PI/2.0f;
   }
+  std::complex<float> parameters(a,b);
   drawCurve(ctx, rect, 0.0f, 1.0f, 0.01f,
       [](float t, void * model, void * context) {
-        ComplexModel * complexModel = (ComplexModel *)model;
+      std::complex<float> parameters = *(std::complex<float> *)model;
         float th = *(float *)context;
-        float factor = 5.0f;
-        float a = std::fabs(complexModel->real())/factor;
-        float b = std::fabs(complexModel->imag())/factor;
-        // Avoid flat ellipsis in edge cases (i or -i)
-        assert(b != 0.0f);
-        a = a == 0.0f ? 1.0f/factor : a;
+        float a = parameters.real();
+        float b = parameters.imag();
         return Poincare::Coordinate2D<float>(a*std::cos(t*th), b*std::sin(t*th));
-    }, m_complex, &th, false, Palette::GreyDark, false);
+    }, &parameters, &th, false, Palette::GreyDark, false);
+
   // Draw dashed segment to indicate real and imaginary
   drawSegment(ctx, rect, Axis::Vertical, real, 0.0f, imag, Palette::Red, 1, 3);
   drawSegment(ctx, rect, Axis::Horizontal, imag, 0.0f, real, Palette::Red, 1, 3);
+
   // Draw complex position on the plan
   drawDot(ctx, rect, real, imag, Palette::Red, true);
+
   // Draw labels
   // 're(z)' label
   drawLabel(ctx, rect, real, 0.0f, "re(z)", Palette::Red, CurveView::RelativePosition::None, imag >= 0.0f ? CurveView::RelativePosition::Before : CurveView::RelativePosition::After);
@@ -80,16 +88,12 @@ void ComplexGraphView::drawRect(KDContext * ctx, KDRect rect) const {
   // 'arg(z)' label, the absolute and relative horizontal/vertical positions of this label depends on the quadrant
   CurveView::RelativePosition horizontalPosition = real >= 0.0f ? CurveView::RelativePosition::After : CurveView::RelativePosition::None;
   verticalPosition = imag >= 0.0f ? CurveView::RelativePosition::After : CurveView::RelativePosition::Before;
-  /* factor is the ratio of the angle where we position the label
+  /* anglePositionRatio is the ratio of the angle where we position the label
    * For the right half plan, we position the label close to the abscissa axis
    * and for the left half plan, we position the label at the half angle. The
    * relative position is chosen accordingly. */
-  float factor = real >= 0.0f ? 0.0f : 0.5f;
-  // The angle represented by flat ellipsis have been avoided previously, so
-  // we positioned its label consistently
-  assert(imag != 0.0f);
-  real = real == 0.0f ? 1.0f : real;
-  drawLabel(ctx, rect, std::fabs(real)/5.0f*std::cos(factor*th), std::fabs(imag)/5.0f*std::sin(factor*th), "arg(z)", Palette::Red, horizontalPosition, verticalPosition);
+  float anglePositionRatio = real >= 0.0f ? 0.0f : 0.5f;
+  drawLabel(ctx, rect, a*std::cos(anglePositionRatio*th), b*std::sin(anglePositionRatio*th), "arg(z)", Palette::Red, horizontalPosition, verticalPosition);
 }
 
 }