From a8d8e72fb48ff6d20d2aaaab75445d0eeb33f463 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Thu, 4 Jul 2019 09:41:24 +0200
Subject: [PATCH] [poincare] Fix MatrixTrace::shallowReduce

---
 poincare/include/poincare/matrix_trace.h |  2 +-
 poincare/src/matrix_trace.cpp            | 36 ++++++++++--------------
 poincare/test/matrix.cpp                 |  6 ++--
 3 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/poincare/include/poincare/matrix_trace.h b/poincare/include/poincare/matrix_trace.h
index cf130c12a..29e7609d3 100644
--- a/poincare/include/poincare/matrix_trace.h
+++ b/poincare/include/poincare/matrix_trace.h
@@ -38,7 +38,7 @@ public:
 
   static constexpr Expression::FunctionHelper s_functionHelper = Expression::FunctionHelper("trace", 1, &UntypedBuilderOneChild<MatrixTrace>);
 
-  Expression shallowReduce();
+  Expression shallowReduce(ExpressionNode::ReductionContext reductionContext);
 };
 
 }
diff --git a/poincare/src/matrix_trace.cpp b/poincare/src/matrix_trace.cpp
index f4dcf03a7..734875692 100644
--- a/poincare/src/matrix_trace.cpp
+++ b/poincare/src/matrix_trace.cpp
@@ -14,7 +14,7 @@ constexpr Expression::FunctionHelper MatrixTrace::s_functionHelper;
 int MatrixTraceNode::numberOfChildren() const { return MatrixTrace::s_functionHelper.numberOfChildren(); }
 
 Expression MatrixTraceNode::shallowReduce(ReductionContext reductionContext) {
-  return MatrixTrace(this).shallowReduce();
+  return MatrixTrace(this).shallowReduce(reductionContext);
 }
 
 Layout MatrixTraceNode::createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
@@ -33,7 +33,7 @@ Evaluation<T> MatrixTraceNode::templatedApproximate(Context * context, Preferenc
 }
 
 
-Expression MatrixTrace::shallowReduce() {
+Expression MatrixTrace::shallowReduce(ExpressionNode::ReductionContext reductionContext) {
   {
     Expression e = Expression::defaultShallowReduce();
     if (e.isUndefined()) {
@@ -41,32 +41,26 @@ Expression MatrixTrace::shallowReduce() {
     }
   }
   Expression c = childAtIndex(0);
-#if MATRIX_EXACT_REDUCING
-#if 0
   if (c.type() == ExpressionNode::Type::Matrix) {
-    Matrix m = static_cast<Matrix&>(c);
-    if (m.numberOfRows() != m.numberOfColumns()) {
-      return Undefined::Builder();
+    Matrix matrixChild = static_cast<Matrix&>(c);
+    if (matrixChild.numberOfRows() != matrixChild.numberOfColumns()) {
+      return replaceWithUndefinedInPlace();
     }
-    int n = m.numberOfRows();
+    int n = matrixChild.numberOfRows();
     Addition a = Addition::Builder();
     for (int i = 0; i < n; i++) {
-      a.addChildAtIndexInPlace(m.childAtIndex(i+n*i), i, a.numberOfChildren());
+      a.addChildAtIndexInPlace(matrixChild.matrixChild(i,i), i, i);
     }
-    return a.shallowReduce(context, complexFormat, angleUnit);
+    replaceWithInPlace(a);
+    return a.shallowReduce(reductionContext);
   }
-  if (!c.recursivelyMatches(Expression::IsMatrix)) {
-    return c;
+  /* TODO LEA
+  if (c.recursivelyMatches(Expression::IsMatrix)) {
+    return *this;
   }
-  return *this;
-#endif
-#else
-  if (c.type() != ExpressionNode::Type::Matrix) {
-    replaceWithInPlace(c);
-    return c;
-  }
-  return *this;
-#endif
+  */
+  replaceWithInPlace(c);
+  return c;
 }
 
 }
diff --git a/poincare/test/matrix.cpp b/poincare/test/matrix.cpp
index eee007696..cd954401a 100644
--- a/poincare/test/matrix.cpp
+++ b/poincare/test/matrix.cpp
@@ -84,10 +84,10 @@ QUIZ_CASE(poincare_matrix_simplify) {
   assert_parsed_expression_simplify_to("dim([[1/√(2),1/2,3][2,1,-3]])", "[[2,3]]");
   assert_parsed_expression_simplify_to("inverse([[1/√(2),1/2,3][2,1,-3]])", Undefined::Name());
   assert_parsed_expression_simplify_to("inverse([[1,2][3,4]])", "inverse([[1,2][3,4]])"); // TODO: implement matrix inverse if dim < 3
-  assert_parsed_expression_simplify_to("trace([[1/√(2),1/2,3][2,1,-3]])", Undefined::Name());
-  assert_parsed_expression_simplify_to("trace([[√(2),2][4,3+log(3)]])", "√(2)+3+log(3)");
-  assert_parsed_expression_simplify_to("trace(√(2)+log(3))", "√(2)+log(3)");
 #endif
+  assert_parsed_expression_simplify_to("trace([[1/√(2),1/2,3][2,1,-3]])", Undefined::Name());
+  assert_parsed_expression_simplify_to("trace([[√(2),2][4,3+log(3)]])", "log(3)+√(2)+3");
+  assert_parsed_expression_simplify_to("trace(√(2)+log(3))", "log(3)+√(2)");
   assert_parsed_expression_simplify_to("transpose([[1/√(2),1/2,3][2,1,-3]])", "[[√(2)/2,2][1/2,1][3,-3]]");
   assert_parsed_expression_simplify_to("transpose(√(4))", "2");
 #if MATRIX_EXACT_REDUCING