diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
index 713d264..fb39569 100644
--- a/example/CMakeLists.txt
+++ b/example/CMakeLists.txt
@@ -10,13 +10,14 @@ macro(add_example name switch)
endif()
endmacro()
-add_example(ex1 ON)
-add_example(ex2 ON)
-add_example(ex3 ON)
-add_example(ex4 ON)
-add_example(ex5 ON)
-add_example(ex6 ON)
-add_example(ex7 ON)
-add_example(ex8 ON)
-add_example(ex9 ON)
-add_example(ex10 ON)
\ No newline at end of file
+add_example(ex1 OFF)
+add_example(ex2 OFF)
+add_example(ex3 OFF)
+add_example(ex4 OFF)
+add_example(ex5 OFF)
+add_example(ex6 OFF)
+add_example(ex7 OFF)
+add_example(ex8 OFF)
+add_example(ex9 OFF)
+add_example(ex10 OFF)
+add_example(cfg_ex ON)
\ No newline at end of file
diff --git a/example/cfg_ex.cpp b/example/cfg_ex.cpp
new file mode 100644
index 0000000..1e5192d
--- /dev/null
+++ b/example/cfg_ex.cpp
@@ -0,0 +1,46 @@
+/********************************************************
+ * ██████╗ ███████╗████████╗██╗
+ * ██╔════╝ ██╔════╝╚══██╔══╝██║
+ * ██║ ███╗███████╗ ██║ ██║
+ * ██║ ██║╚════██║ ██║ ██║
+ * ╚██████╔╝███████║ ██║ ███████╗
+ * ╚═════╝ ╚══════╝ ╚═╝ ╚══════╝
+ * Generic Scientific Template Library
+ *
+ * Copyright (c) 2022 Yi Zhang (yizhang-geo@zju.edu.cn)
+ *
+ * The GSTL is distributed under a dual licensing scheme. You can redistribute
+ * it and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either version 2
+ * of the License, or (at your option) any later version. You should have
+ * received a copy of the GNU Lesser General Public License (LGPL) along with
+ * this program. If not, see .
+ *
+ * If the terms and conditions of the LGPL v.2. would prevent you from using
+ * the GSTL, please consider the option to obtain a commercial license for a
+ * fee. These licenses are offered by the GSTL's original author. As a rule,
+ * licenses are provided "as-is", unlimited in time for a one time fee. Please
+ * send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
+ * to include some description of your company and the realm of its activities.
+ * Also add information on how to contact you by electronic and paper mail.
+ ******************************************************/
+
+#include "../lib/optimization/cmn_grad.h"
+
+using namespace gctl;
+
+int main(int argc, char *argv[]) try
+{
+ common_gradient cmg;
+ cmg.init(2, 2);
+ cmg.fill_model_gradient(0, _1d_array({1.0, 0.5}));
+ cmg.fill_model_gradient(1, _1d_array({-0.6, 1.0}));
+
+ _1d_array x = cmg.get_common_gradient(false);
+ std::cout << "x = (" << x[0] << ", " << x[1] << ")\n";
+ return 0;
+}
+catch (const std::exception& e)
+{
+ GCTL_ShowWhatError(e.what(), GCTL_ERROR_ERROR, 0, 0, 0);
+}
\ No newline at end of file
diff --git a/lib/optimization.h b/lib/optimization.h
index 6d8f3a1..1ede1f8 100644
--- a/lib/optimization.h
+++ b/lib/optimization.h
@@ -39,5 +39,6 @@
#include "optimization/sgd.h"
#include "optimization/gradnorm.h"
#include "optimization/dwa.h"
+#include "optimization/cmn_grad.h"
#endif // _GCTL_OPTIMIZATION_H
\ No newline at end of file
diff --git a/lib/optimization/clcg.h b/lib/optimization/clcg.h
index dabb5ff..8856ab7 100644
--- a/lib/optimization/clcg.h
+++ b/lib/optimization/clcg.h
@@ -28,6 +28,7 @@
#ifndef _GCTL_CLCG_H
#define _GCTL_CLCG_H
+#include "gctl/utility.h"
#include "gctl/core.h"
#include "gctl/maths.h"
#include "gctl/algorithms.h"
diff --git a/lib/optimization/cmn_grad.cpp b/lib/optimization/cmn_grad.cpp
new file mode 100644
index 0000000..3404c6e
--- /dev/null
+++ b/lib/optimization/cmn_grad.cpp
@@ -0,0 +1,110 @@
+/********************************************************
+ * ██████╗ ██████╗████████╗██╗
+ * ██╔════╝ ██╔════╝╚══██╔══╝██║
+ * ██║ ███╗██║ ██║ ██║
+ * ██║ ██║██║ ██║ ██║
+ * ╚██████╔╝╚██████╗ ██║ ███████╗
+ * ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
+ * Geophysical Computational Tools & Library (GCTL)
+ *
+ * Copyright (c) 2023 Yi Zhang (yizhang-geo@zju.edu.cn)
+ *
+ * GCTL is distributed under a dual licensing scheme. You can redistribute
+ * it and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either version 2
+ * of the License, or (at your option) any later version. You should have
+ * received a copy of the GNU Lesser General Public License along with this
+ * program. If not, see .
+ *
+ * If the terms and conditions of the LGPL v.2. would prevent you from using
+ * the GCTL, please consider the option to obtain a commercial license for a
+ * fee. These licenses are offered by the GCTL's original author. As a rule,
+ * licenses are provided "as-is", unlimited in time for a one time fee. Please
+ * send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
+ * to include some description of your company and the realm of its activities.
+ * Also add information on how to contact you by electronic and paper mail.
+ ******************************************************/
+
+#include "cmn_grad.h"
+
+gctl::common_gradient::common_gradient()
+{
+ set_lcg_message(LCG_THROW);
+}
+
+gctl::common_gradient::common_gradient(size_t Ln, size_t Mn)
+{
+ init(Ln, Mn);
+}
+
+gctl::common_gradient::~common_gradient(){}
+
+void gctl::common_gradient::LCG_Ax(const array &x, array &ax)
+{
+ matvec(t_, G_, x, NoTrans);
+ matvec(ax, G_, t_, Trans);
+ return;
+}
+
+void gctl::common_gradient::set_solver(const lcg_para ¶)
+{
+ set_lcg_para(para);
+ return;
+}
+
+void gctl::common_gradient::init(size_t Ln, size_t Mn)
+{
+ Ln_ = Ln;
+ Mn_ = Mn;
+ g_.resize(Mn_);
+ B_.resize(Mn_);
+ G_.resize(Ln_, Mn_);
+ t_.resize(Ln_);
+ gm_.resize(Ln_);
+ x_.resize(Ln_, 1.0);
+ filled_.resize(Ln_, false);
+ return;
+}
+
+void gctl::common_gradient::fill_model_gradient(size_t id, const _1d_array &g)
+{
+ if (id >= Ln_) throw std::runtime_error("[gctl::common_gradient] Invalid index.");
+ if (g.size() != Mn_) throw std::runtime_error("[gctl::common_gradient] Invalid array size.");
+
+ G_.fill_row(id, g);
+ filled_[id] = true;
+ gm_[id] = g.module();
+ return;
+}
+
+const gctl::_1d_array &gctl::common_gradient::get_common_gradient(bool normalized)
+{
+ for (size_t i = 0; i < Ln_; i++)
+ {
+ if (!filled_[i]) throw std::runtime_error("[gctl::common_gradient] Unfilled model gradient.");
+ }
+ filled_.assign(false);
+
+ G_.normalize(RowMajor);
+ matvec(B_, G_, x_, Trans);
+
+ g_.random_float(-1.0, 1.0, RdUniform);
+ g_.normalize();
+ LCG_Minimize(g_, B_, LCG_CG);
+
+ if (normalized) g_.normalize();
+ else
+ {
+ g_.normalize();
+ matvec(t_, G_, g_, NoTrans);
+
+ double tmod = t_.module(L1);
+ double gmod = 0.0;
+ for (size_t i = 0; i < Ln_; i++)
+ {
+ gmod += gm_[i]*abs(t_[i])/tmod;
+ }
+ g_.scale(gmod);
+ }
+ return g_;
+}
\ No newline at end of file
diff --git a/lib/optimization/cmn_grad.h b/lib/optimization/cmn_grad.h
new file mode 100644
index 0000000..5fcb21e
--- /dev/null
+++ b/lib/optimization/cmn_grad.h
@@ -0,0 +1,92 @@
+/********************************************************
+ * ██████╗ ██████╗████████╗██╗
+ * ██╔════╝ ██╔════╝╚══██╔══╝██║
+ * ██║ ███╗██║ ██║ ██║
+ * ██║ ██║██║ ██║ ██║
+ * ╚██████╔╝╚██████╗ ██║ ███████╗
+ * ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
+ * Geophysical Computational Tools & Library (GCTL)
+ *
+ * Copyright (c) 2023 Yi Zhang (yizhang-geo@zju.edu.cn)
+ *
+ * GCTL is distributed under a dual licensing scheme. You can redistribute
+ * it and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either version 2
+ * of the License, or (at your option) any later version. You should have
+ * received a copy of the GNU Lesser General Public License along with this
+ * program. If not, see .
+ *
+ * If the terms and conditions of the LGPL v.2. would prevent you from using
+ * the GCTL, please consider the option to obtain a commercial license for a
+ * fee. These licenses are offered by the GCTL's original author. As a rule,
+ * licenses are provided "as-is", unlimited in time for a one time fee. Please
+ * send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
+ * to include some description of your company and the realm of its activities.
+ * Also add information on how to contact you by electronic and paper mail.
+ ******************************************************/
+
+#ifndef _GCTL_COMMON_GRADIENT_H
+#define _GCTL_COMMON_GRADIENT_H
+
+#include "lcg.h"
+
+namespace gctl
+{
+ class common_gradient : public lcg_solver
+ {
+ public:
+ common_gradient(); ///< 构造函数
+
+ /**
+ * @brief Construct a new common_gradient object
+ *
+ * @param Ln Number of loss functions
+ * @param Mn Number of model parameters
+ */
+ common_gradient(size_t Ln, size_t Mn);
+
+ virtual ~common_gradient(); ///< 析构函数
+
+ virtual void LCG_Ax(const array &x, array &ax); ///< 计算Ax
+
+ /**
+ * @brief Configure the solver's setups
+ *
+ * @param para LCG solver parameters
+ */
+ void set_solver(const lcg_para ¶);
+
+ /**
+ * @brief Initialize the common_gradient object
+ *
+ * @param Ln Number of loss functions
+ * @param Mn Number of model parameters
+ */
+ void init(size_t Ln, size_t Mn);
+
+ /**
+ * @brief Fill the model gradient
+ *
+ * @param id Loss function index
+ * @param g Model gradient
+ */
+ void fill_model_gradient(size_t id, const _1d_array &g);
+
+ /**
+ * @brief Get the conflict free gradient
+ *
+ * @param normalized Normalize the output gradient
+ * @return Calculated model gradient
+ */
+ const _1d_array &get_common_gradient(bool normalized = true);
+
+ private:
+ size_t Ln_, Mn_; // Ln_: loss_func number，Mn_: model number
+ _2d_matrix G_;
+ _1d_array B_, g_, t_, x_;
+ _1d_array gm_;
+ array filled_;
+ };
+};
+
+#endif // _GCTL_COMMON_GRADIENT_H
\ No newline at end of file
diff --git a/lib/optimization/lbfgs.h b/lib/optimization/lbfgs.h
index 7b35850..7afb183 100644
--- a/lib/optimization/lbfgs.h
+++ b/lib/optimization/lbfgs.h
@@ -28,6 +28,7 @@
#ifndef _GCTL_LBFGS_H
#define _GCTL_LBFGS_H
+#include "gctl/utility.h"
#include "gctl/core.h"
#include "gctl/maths.h"
#include "gctl/algorithms.h"
diff --git a/lib/optimization/sgd.h b/lib/optimization/sgd.h
index 0fd2607..cae9e91 100644
--- a/lib/optimization/sgd.h
+++ b/lib/optimization/sgd.h
@@ -28,6 +28,7 @@
#ifndef _GCTL_SGD_H
#define _GCTL_SGD_H
+#include "gctl/utility.h"
#include "gctl/core.h"
#include "gctl/algorithms.h"