From 1410b5d85a34986522ef09bd41c78a166da3143f Mon Sep 17 00:00:00 2001
From: Markus Neumann <markus.neumann@uzh.ch>
Date: Tue, 18 Apr 2017 11:49:58 +0200
Subject: [PATCH] add minus, unary minus and tests for both. changed version to
 0.2

---
 HierMat/hmat.py    | 28 +++++++++++++++++++++++++---
 setup.py           |  2 +-
 tests/test_hmat.py | 24 ++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/HierMat/hmat.py b/HierMat/hmat.py
index 5ab4cc8..b32213b 100644
--- a/HierMat/hmat.py
+++ b/HierMat/hmat.py
@@ -26,14 +26,16 @@ class HMat(object):
         
         * ``*`` (formatted multiplication)
         
+        * ``-a`` (unary minus)
+        
+        * ``-`` (formatted subtraction)
+        
         * ``==`` (equal)
         
         * ``!=`` (not equal)
     
     .. todo::
     
-        * implement ``-``
-        
         * implement ``norm`` and ``__abs__``
         
         * implement ``inv``
@@ -182,7 +184,9 @@ def _add_matrix(self, other):
             for block in self.blocks:
                 start_x = block.root_index[0] - self.root_index[0]
                 start_y = block.root_index[1] - self.root_index[1]
-                out.blocks.append(block + other[start_x: start_x + block.shape[0], start_y: start_y + block.shape[1]])
+                end_x = start_x + block.shape[0]
+                end_y = start_y + block.shape[1]
+                out.blocks.append(block + other[start_x: end_x, start_y: end_y])
         else:
             out.content = self.content + other
         return out
@@ -191,6 +195,24 @@ def __radd__(self, other):
         """Should be commutative so just switch"""
         return self + other
 
+    def __neg__(self):
+        """Unary minus"""
+        out = HMat(shape=self.shape, root_index=self.root_index)
+        if self.content is not None:
+            out.content = -self.content
+        else:
+            out.blocks = []
+            for block in self.blocks:
+                out.blocks.append(-block)
+        return out
+
+    def __sub__(self, other):
+        """Subtract other
+        
+        :type other: HMat
+        """
+        return self + (-other)
+
     def __mul__(self, other):
         """multiplication with several types"""
         if isinstance(other, numpy.matrix):  # order is important here!
diff --git a/setup.py b/setup.py
index b17b259..0711969 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 
 setup(
     name='HierMat',
-    version='0.1',
+    version='0.2',
     packages=['HierMat'],
     url='http://hierarchicalmatrices.readthedocs.io/en/latest/index.html',
     download_url='https://github.com/maekke97/HierarchicalMatrices',
diff --git a/tests/test_hmat.py b/tests/test_hmat.py
index 487ef25..ca91599 100644
--- a/tests/test_hmat.py
+++ b/tests/test_hmat.py
@@ -163,6 +163,30 @@ def test_radd(self):
         res = addend_hmat.__radd__(mat)
         self.assertEqual(addend_hmat, res)
 
+    def test_neg(self):
+        negcmat1 = HMat(content=-self.cblock1, shape=(3, 2), root_index=(0, 0))
+        negcmat2 = HMat(content=-self.cblock2, shape=(3, 1), root_index=(0, 2))
+        negcmat3 = HMat(content=-self.cblock3, shape=(3, 3), root_index=(0, 3))
+        negcmat4 = HMat(content=-self.cblock4, shape=(2, 2), root_index=(3, 0))
+        negcmat5 = HMat(content=-self.cblock5, shape=(2, 1), root_index=(3, 2))
+        negcmat6 = HMat(content=-self.cblock6, shape=(2, 3), root_index=(3, 3))
+        negconsistent1 = HMat(blocks=[negcmat1, negcmat2, negcmat3, negcmat4, negcmat5, negcmat6],
+                              shape=(5, 6), root_index=(0, 0))
+        self.assertEqual(-self.cmat1, negcmat1)
+        self.assertEqual(-self.consistent1, negconsistent1)
+
+    def test_minus(self):
+        zercmat1 = HMat(content=numpy.matrix(numpy.zeros((3, 2))), shape=(3, 2), root_index=(0, 0))
+        zercmat2 = HMat(content=numpy.matrix(numpy.zeros((3, 1))), shape=(3, 1), root_index=(0, 2))
+        zercmat3 = HMat(content=numpy.matrix(numpy.zeros((3, 3))), shape=(3, 3), root_index=(0, 3))
+        zercmat4 = HMat(content=numpy.matrix(numpy.zeros((2, 2))), shape=(2, 2), root_index=(3, 0))
+        zercmat5 = HMat(content=numpy.matrix(numpy.zeros((2, 1))), shape=(2, 1), root_index=(3, 2))
+        zercmat6 = HMat(content=numpy.matrix(numpy.zeros((2, 3))), shape=(2, 3), root_index=(3, 3))
+        zerconsistent1 = HMat(blocks=[zercmat1, zercmat2, zercmat3, zercmat4, zercmat5, zercmat6],
+                              shape=(5, 6), root_index=(0, 0))
+        self.assertEqual(self.cmat1 - self.cmat1, zercmat1)
+        self.assertEqual(self.consistent1 - self.consistent1, zerconsistent1)
+
     def test_repr(self):
         check = '<HMat with {content}>'.format(content=self.hmat_lvl2.blocks)
         self.assertEqual(self.hmat_lvl2.__repr__(), check)