diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
index 5504d9f..d423749 100644
--- a/example/CMakeLists.txt
+++ b/example/CMakeLists.txt
@@ -21,11 +21,11 @@ add_example(fft_filter_ex OFF)
 add_example(windowfunc_ex OFF)
 add_example(legendre_ex OFF)
 add_example(refellipsoid_ex OFF)
-add_example(kde_ex ON)
+add_example(kde_ex OFF)
 add_example(meshio_ex OFF)
 add_example(autodiff_ex OFF)
 add_example(multinary_ex OFF)
 add_example(text_io_ex OFF)
 add_example(getoption_ex OFF)
 add_example(process_ex OFF)
-add_example(array_ex OFF)
\ No newline at end of file
+add_example(array_ex ON)
\ No newline at end of file
diff --git a/example/array_ex.cpp b/example/array_ex.cpp
index 6e51ab6..34c84f6 100644
--- a/example/array_ex.cpp
+++ b/example/array_ex.cpp
@@ -41,6 +41,9 @@ int main(int argc, char const *argv[]) try
 	A.for_each([](double &a, size_t i){ a += 1;});
 	A.show();
 
+	A.sequence(1.0, 0.5, 3, 4, 1);
+	A.show();
+
 	// copy A to a new array
 	array<double> B = A;
 	B.normalize();
@@ -53,6 +56,10 @@ int main(int argc, char const *argv[]) try
 	S.normalize();
 	S.show();
 
+	array<point3dc> P(5);
+	P.sequence(point3dc(0, 0, 0), point3dc(2, 1, 0.5));
+	P.show(std::cout, '\n');
+
 	// create a new 2D array
 	matrix<int> C(5, 5, 1);
 	C.sequence(0, 1, 10);
diff --git a/lib/algorithm/interpolate.cpp b/lib/algorithm/interpolate.cpp
index 6b118cb..0888f47 100644
--- a/lib/algorithm/interpolate.cpp
+++ b/lib/algorithm/interpolate.cpp
@@ -129,21 +129,23 @@ double gctl::sph_linear_interpolate_deg(double CoLat1,double CoLat2,double Lon1,
 // 插值点坐标x y
 // 四个角点值
 double gctl::rect_interpolate(double x0,double y0,double dx,double dy,double x,double y,
-					double d0,double d1,double d2,double d3)
+	double d0,double d1,double d2,double d3, double p)
 {
 	double res = 0;
 	double total_dist = 0;
 	double dist[4] = {0,0,0,0};
 	double val[4];
 	val[0] = d0; val[1] = d1; val[2] = d2; val[3] = d3;
-	dist[0] = 1.0/(1e-30+(x-x0)*(x-x0)+(y-y0)*(y-y0));
-	dist[1] = 1.0/(1e-30+(x-dx-x0)*(x-dx-x0)+(y-y0)*(y-y0));
-	dist[2] = 1.0/(1e-30+(x-dx-x0)*(x-dx-x0)+(y-dy-y0)*(y-dy-y0));
-	dist[3] = 1.0/(1e-30+(x-x0)*(x-x0)+(y-dy-y0)*(y-dy-y0));
+	dist[0] = 1.0/(1e-30 + pow((x-x0)*(x-x0)+(y-y0)*(y-y0), 0.5*p));
+	dist[1] = 1.0/(1e-30 + pow((x-dx-x0)*(x-dx-x0)+(y-y0)*(y-y0), 0.5*p));
+	dist[2] = 1.0/(1e-30 + pow((x-dx-x0)*(x-dx-x0)+(y-dy-y0)*(y-dy-y0), 0.5*p));
+	dist[3] = 1.0/(1e-30 + pow((x-x0)*(x-x0)+(y-dy-y0)*(y-dy-y0), 0.5*p));
+
 	for (int i = 0; i < 4; i++)
 	{
 		total_dist += dist[i];
 	}
+
 	for (int i = 0; i < 4; i++)
 	{
 		res += val[i]*dist[i]/total_dist;
diff --git a/lib/algorithm/interpolate.h b/lib/algorithm/interpolate.h
index 6718333..ce38ca7 100644
--- a/lib/algorithm/interpolate.h
+++ b/lib/algorithm/interpolate.h
@@ -133,7 +133,7 @@ namespace gctl
 	/**
 	 * @brief      规则网络插值 长方形内数据插值
 	 * 
-	 * @note 距离平方反比
+	 * @note 默认为距离平方反比
 	 * 
 	 * y
 	 * |
@@ -157,11 +157,12 @@ namespace gctl
 	 * @param[in]  d1    d1值
 	 * @param[in]  d2    d2值
 	 * @param[in]  d3    d3值
+	 * @param[in]  p     距离次方值 默认为2
 	 *
 	 * @return     插值点值
 	 */
 	double rect_interpolate(double x0, double y0, double dx, double dy, double x, double y,
-		double d0, double d1, double d2, double d3);
+		double d0, double d1, double d2, double d3, double p = 2.0);
 
 	/**
 	 * @brief      规则网络插值 长方体内数据插值
diff --git a/lib/core/array.h b/lib/core/array.h
index ceb5998..ba00579 100644
--- a/lib/core/array.h
+++ b/lib/core/array.h
@@ -528,8 +528,12 @@ namespace gctl
 		 * 
 		 * @param st_val  Start value.
 		 * @param inc Increasement.
+		 * @param st_id Start index.
+		 * @param size Operating size.
+		 * @param space Indexing spacing.
 		 */
-		void sequence(ArrValType st_val, ArrValType inc);
+		void sequence(ArrValType st_val, ArrValType inc, size_t st_id = 0, 
+			size_t size = std::numeric_limits<size_t>::max(), size_t space = 0);
 
 		/**
 		 * @brief Assign values as a 2D sequence.
@@ -1328,14 +1332,27 @@ namespace gctl
 	}
 
 	template <typename ArrValType>
-	void array<ArrValType>::sequence(ArrValType st_val, ArrValType inc)
+	void array<ArrValType>::sequence(ArrValType st_val, ArrValType inc, 
+		size_t st_id, size_t size, size_t space)
 	{
-		//static_assert(std::is_arithmetic<ArrValType>::value, 
-		//	"gctl::array<T>::sequence(...) could only be used with an arithmetic type.");
+		if (st_id >= length_) throw std::runtime_error("[gctl::array<T>::sequence] Invalid index.");
+		size = GCTL_MIN(size, length_);
 
-		for (size_t i = 0; i < length_; i++)
+		if (size > 0)
 		{
-			val_[i] = st_val + i*inc;
+			val_[st_id] = st_val;
+			size--;
+
+			size_t id = st_id;
+			size_t id2 = st_id + space + 1;
+			while (id2 < length_ && size > 0)
+			{
+				val_[id2] = val_[id] + inc;
+
+				id = id2;
+				id2 += space + 1;
+				size--;
+			}
 		}
 		return;
 	}
@@ -1344,9 +1361,6 @@ namespace gctl
 	void array<ArrValType>::sequence2d(ArrValType rs, ArrValType rinc, 
 		ArrValType cs, ArrValType cinc, size_t rn, size_t cn)
 	{
-		//static_assert(std::is_arithmetic<ArrValType>::value, 
-		//	"gctl::array<T>::sequence2d(...) could only be used with an arithmetic type.");
-
 		if (rn*cn != length_)
 		{
 			throw invalid_argument("[gctl::array<T>::sequence2d] Invalid sequence sizes.");
@@ -1371,9 +1385,6 @@ namespace gctl
 		ArrValType rs, ArrValType rinc, ArrValType cs, ArrValType cinc, 
 		size_t ln, size_t rn, size_t cn)
 	{
-		//static_assert(std::is_arithmetic<ArrValType>::value, 
-		//	"gctl::array<T>::sequence3d(...) could only be used with an arithmetic type.");
-
 		if (ln*rn*cn != length_)
 		{
 			throw invalid_argument("[gctl::array<T>::sequence3d] Invalid sequence sizes.");