From b58cfee5a1f9f895bdbb58da0e6e3ffb4d2b1ce5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Wed, 31 May 2017 12:05:59 +0200
Subject: [PATCH] [poincare] Clean matrix power

Change-Id: I7ff27b45f240e0f6c89fb5bf79f21126475265e4
---
 poincare/include/poincare/matrix.h |  1 +
 poincare/src/matrix.cpp            | 16 ++++++++++++++++
 poincare/src/power.cpp             | 18 ++----------------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/poincare/include/poincare/matrix.h b/poincare/include/poincare/matrix.h
index 3bd7d0b68..1b736aab4 100644
--- a/poincare/include/poincare/matrix.h
+++ b/poincare/include/poincare/matrix.h
@@ -33,6 +33,7 @@ public:
   float determinant(Context& context, AngleUnit angleUnit) const;
   Expression * createInverse(Context& context, AngleUnit angleUnit) const;
   Expression * createTranspose(Context& context, AngleUnit angleUnit) const;
+  static Expression * createIdentity(int dim);
 private:
   ExpressionLayout * privateCreateLayout(FloatDisplayMode floatDisplayMode, ComplexFormat complexFormat) const override;
   float privateApproximate(Context& context, AngleUnit angleUnit) const override;
diff --git a/poincare/src/matrix.cpp b/poincare/src/matrix.cpp
index 029797e19..1fee60037 100644
--- a/poincare/src/matrix.cpp
+++ b/poincare/src/matrix.cpp
@@ -318,4 +318,20 @@ Expression * Matrix::createTranspose(Context& context, AngleUnit angleUnit) cons
   return matrix;
 }
 
+Expression * Matrix::createIdentity(int dim) {
+  Expression ** operands = (Expression **)malloc(dim*dim*sizeof(Expression *));
+  for (int i = 0; i < dim; i++) {
+    for (int j = 0; j < dim; j++) {
+      if (i == j) {
+        operands[i*dim+j] = new Complex(Complex::Float(1.0f));
+      } else {
+        operands[i*dim+j] = new Complex(Complex::Float(0.0f));
+      }
+    }
+  }
+  Expression * matrix = new Matrix(new MatrixData(operands, dim*dim, dim, dim, false));
+  free(operands);
+  return matrix;
+}
+
 }
diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index f021a0715..d9bc42d28 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -78,28 +78,14 @@ Expression * Power::evaluateOnMatrixAndComplex(Matrix * m, Complex * c, Context&
   }
   if (power == 0.0f) {
     /* Build the identity matrix with the same dimensions as m */
-    Expression ** operands = (Expression **)malloc(m->numberOfOperands()*sizeof(Expression *));
-    for (int i = 0; i < m->numberOfRows(); i++) {
-      for (int j = 0; j < m->numberOfColumns(); j++) {
-        if (i == j) {
-          operands[i*m->numberOfColumns()+j] = new Complex(Complex::Float(1.0f));
-        } else {
-          operands[i*m->numberOfColumns()+j] = new Complex(Complex::Float(0.0f));
-        }
-      }
-    }
-    Expression * matrix = new Matrix(new MatrixData(operands, m->numberOfOperands(), m->numberOfColumns(), m->numberOfRows(), false));
-    free(operands);
-    return matrix;
+    return Matrix::createIdentity(m->numberOfRows());
   }
   if (power < 0.0f) {
     Expression * inverse = m->createInverse(context, angleUnit);
     Expression * operands[2];
     operands[0] = inverse;
     operands[1] = new Complex(Complex::Float(-power));;
-    Expression * power = new Power(operands, true);
-    delete operands[0];
-    delete operands[1];
+    Expression * power = new Power(operands, false);
     Expression * result = power->evaluate(context, angleUnit);
     delete power;
     return result;