diff --git a/README.md b/README.md
index cec9831..3690c01 100644
--- a/README.md
+++ b/README.md
@@ -49,22 +49,25 @@ Please also note that the basic data structures in OpenCV (e.g., `cv::Mat`, `cv:
 ```go
 package main
 
-import "github.com/lazywei/go-opencv/gocv"
+import . "github.com/lazywei/go-opencv/gocv"
+import "github.com/gonum/matrix/mat64"
 
 func main() {
-	objPts := gocv.NewGcvPoint3fVector(int64(4))
-	objPts.Set(0, gocv.NewGcvPoint3f(0, 25, 0))
-	objPts.Set(1, gocv.NewGcvPoint3f(0, -25, 0))
-	objPts.Set(2, gocv.NewGcvPoint3f(-47, 25, 0))
-	objPts.Set(3, gocv.NewGcvPoint3f(-47, -25, 0))
 
-	imgPts := gocv.NewGcvPoint2fVector(int64(4))
-	imgPts.Set(0, gocv.NewGcvPoint2f(1136.4140625, 1041.89208984))
-	imgPts.Set(1, gocv.NewGcvPoint2f(1845.33190918, 671.39581299))
-	imgPts.Set(2, gocv.NewGcvPoint2f(302.73373413, 634.79998779))
-	imgPts.Set(3, gocv.NewGcvPoint2f(1051.46154785, 352.76107788))
+	objPts := mat64.NewDense(4, 3, []float64{
+		0, 25, 0,
+		0, -25, 0,
+		-47, 25, 0,
+		-47, -25, 0})
 
-	gocv.GcvInitCameraMatrix2D(objPts, imgPts)
+	imgPts := mat64.NewDense(4, 2, []float64{
+		1136.4140625, 1041.89208984,
+		1845.33190918, 671.39581299,
+		302.73373413, 634.79998779,
+		1051.46154785, 352.76107788})
+
+	camMat := GcvInitCameraMatrix2D(objPts, imgPts)
+	fmt.Println(camMat)
 }
 ```
 
diff --git a/gocv/gocv_calib3d_test.go b/gocv/gocv_calib3d_test.go
new file mode 100644
index 0000000..72115ef
--- /dev/null
+++ b/gocv/gocv_calib3d_test.go
@@ -0,0 +1,55 @@
+package gocv
+
+import (
+	"testing"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/gonum/matrix/mat64"
+)
+
+func TestGcvInitCameraMatrix2D(t *testing.T) {
+	objPts := mat64.NewDense(4, 3, []float64{
+		0, 25, 0,
+		0, -25, 0,
+		-47, 25, 0,
+		-47, -25, 0})
+
+	imgPts := mat64.NewDense(4, 2, []float64{
+		1136.4140625, 1041.89208984,
+		1845.33190918, 671.39581299,
+		302.73373413, 634.79998779,
+		1051.46154785, 352.76107788})
+
+	camMat := GcvInitCameraMatrix2D(objPts, imgPts)
+	spew.Dump(camMat)
+}
+
+// func TestGcvCalibrateCamera(t *testing.T) {
+// 	objPts := NewGcvPoint3fVector(int64(4))
+// 	objPts.Set(0, NewGcvPoint3f(0, 25, 0))
+// 	objPts.Set(1, NewGcvPoint3f(0, -25, 0))
+// 	objPts.Set(2, NewGcvPoint3f(-47, 25, 0))
+// 	objPts.Set(3, NewGcvPoint3f(-47, -25, 0))
+
+// 	imgPts := NewGcvPoint2fVector(int64(4))
+// 	imgPts.Set(0, NewGcvPoint2f(1136.4140625, 1041.89208984))
+// 	imgPts.Set(1, NewGcvPoint2f(1845.33190918, 671.39581299))
+// 	imgPts.Set(2, NewGcvPoint2f(302.73373413, 634.79998779))
+// 	imgPts.Set(3, NewGcvPoint2f(1051.46154785, 352.76107788))
+
+// 	imgSize := NewGcvSize2i(1920, 1080)
+
+// 	camMat := GcvInitCameraMatrix2D(objPts, imgPts)
+// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(0, 0)))
+// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(0, 1)))
+// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(1, 1)))
+// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(1, 2)))
+// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(2, 2)))
+
+// 	rvec := NewMat()
+// 	tvec := NewMat()
+
+// 	GcvCalibrateCamera(objPts, imgPts, imgSize, camMat, rvec, tvec)
+
+// 	MatToMat64(camMat)
+// }
diff --git a/gocv/gocv_test.go b/gocv/gocv_test.go
index dae57c7..228cba8 100644
--- a/gocv/gocv_test.go
+++ b/gocv/gocv_test.go
@@ -4,7 +4,6 @@ import (
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
-	"github.com/gonum/matrix/mat64"
 )
 
 func TestNewGcvPoint3f32(t *testing.T) {
@@ -27,50 +26,3 @@ func TestMat(t *testing.T) {
 	mat2 := NewMat(mat)
 	spew.Dump(mat2)
 }
-
-func TestGcvInitCameraMatrix2D(t *testing.T) {
-	objPts := mat64.NewDense(4, 3, []float64{
-		0, 25, 0,
-		0, -25, 0,
-		-47, 25, 0,
-		-47, -25, 0})
-
-	imgPts := mat64.NewDense(4, 2, []float64{
-		1136.4140625, 1041.89208984,
-		1845.33190918, 671.39581299,
-		302.73373413, 634.79998779,
-		1051.46154785, 352.76107788})
-
-	camMat := GcvInitCameraMatrix2D(objPts, imgPts)
-	spew.Dump(camMat)
-}
-
-// func TestGcvCalibrateCamera(t *testing.T) {
-// 	objPts := NewGcvPoint3fVector(int64(4))
-// 	objPts.Set(0, NewGcvPoint3f(0, 25, 0))
-// 	objPts.Set(1, NewGcvPoint3f(0, -25, 0))
-// 	objPts.Set(2, NewGcvPoint3f(-47, 25, 0))
-// 	objPts.Set(3, NewGcvPoint3f(-47, -25, 0))
-
-// 	imgPts := NewGcvPoint2fVector(int64(4))
-// 	imgPts.Set(0, NewGcvPoint2f(1136.4140625, 1041.89208984))
-// 	imgPts.Set(1, NewGcvPoint2f(1845.33190918, 671.39581299))
-// 	imgPts.Set(2, NewGcvPoint2f(302.73373413, 634.79998779))
-// 	imgPts.Set(3, NewGcvPoint2f(1051.46154785, 352.76107788))
-
-// 	imgSize := NewGcvSize2i(1920, 1080)
-
-// 	camMat := GcvInitCameraMatrix2D(objPts, imgPts)
-// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(0, 0)))
-// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(0, 1)))
-// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(1, 1)))
-// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(1, 2)))
-// 	spew.Dump(camMat.GcvAtd(NewGcvSize2i(2, 2)))
-
-// 	rvec := NewMat()
-// 	tvec := NewMat()
-
-// 	GcvCalibrateCamera(objPts, imgPts, imgSize, camMat, rvec, tvec)
-
-// 	MatToMat64(camMat)
-// }