Added access tests and added full bounds checking to At and Set

facugaich · Mar 17, 2014 · d46424e · d46424e
1 parent 4ecb412
commit d46424e
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Showing 2 changed files with 45 additions and 4 deletions.
diff --git a/mat64/dense.go b/mat64/dense.go
@@ -97,15 +97,21 @@ func (m *Dense) isZero() bool {
 }
 
 func (m *Dense) At(r, c int) float64 {
-	if c >= m.mat.Cols {
-		panic("dense access out of bounds")
+	if r >= m.mat.Rows || r < 0 {
+		panic("index error: row access out of bounds")
+	}
+	if c >= m.mat.Cols || c < 0 {
+		panic("index error: column access out of bounds")
 	}
 	return m.mat.Data[r*m.mat.Stride+c]
 }
 
 func (m *Dense) Set(r, c int, v float64) {
-	if c >= m.mat.Cols {
-		panic("dense access out of bounds")
+	if r >= m.mat.Rows || r < 0 {
+		panic("index error: row access out of bounds")
+	}
+	if c >= m.mat.Cols || c < 0 {
+		panic("index error: column access out of bounds")
 	}
 	m.mat.Data[r*m.mat.Stride+c] = v
 }

diff --git a/mat64/dense_test.go b/mat64/dense_test.go
@@ -126,6 +126,41 @@ func (s *S) TestNewDense(c *check.C) {
 	}
 }
 
+func (s *S) TestAtSet(c *check.C) {
+	for test, af := range [][][]float64{
+		{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, // even
+		{{1, 2}, {4, 5}, {7, 8}},          // wide
+		{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, //skinny
+	} {
+		m := NewDense(flatten(af))
+		rows, cols := m.Dims()
+		for i := 0; i < rows; i++ {
+			for j := 0; j < cols; j++ {
+				c.Check(m.At(i, j), check.Equals, af[i][j], check.Commentf("At test %d", test))
+
+				v := float64(i * j)
+				m.Set(i, j, v)
+				c.Check(m.At(i, j), check.Equals, v, check.Commentf("Set test %d", test))
+			}
+		}
+		// Check access out of bounds fails
+		c.Check(func() { m.At(rows, 0) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.At(rows+1, 0) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.At(0, cols) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.At(0, cols+1) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.At(-1, 0) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.At(0, -1) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+
+		// Check access out of bounds fails
+		c.Check(func() { m.Set(rows, 0, 1.2) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.Set(rows+1, 0, 1.2) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.Set(0, cols, 1.2) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.Set(0, cols+1, 1.2) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.Set(-1, 0, 1.2) }, check.PanicMatches, "index error: row access out of bounds", check.Commentf("Test %d", test))
+		c.Check(func() { m.Set(0, -1, 1.2) }, check.PanicMatches, "index error: column access out of bounds", check.Commentf("Test %d", test))
+	}
+}
+
 func (s *S) TestRowCol(c *check.C) {
 	for i, af := range [][][]float64{
 		{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}},