gctl/lib/math/gmath.cpp
2025-04-23 13:43:40 +08:00

1207 lines
35 KiB
C++

/********************************************************
* ██████╗ ██████╗████████╗██╗
* ██╔════╝ ██╔════╝╚══██╔══╝██║
* ██║ ███╗██║ ██║ ██║
* ██║ ██║██║ ██║ ██║
* ╚██████╔╝╚██████╗ ██║ ███████╗
* ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
* 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 <http://www.gnu.org/licenses/>.
*
* 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 "gmath.h"
int gctl::random(int low, int hig)
{
return rand()%(hig - low + 1) + low;
}
double gctl::random(double low, double hig)
{
double f = (double) rand()/RAND_MAX;
return f*(hig-low) + low;
}
std::complex<double> gctl::random(std::complex<double> low, std::complex<double> hig)
{
std::complex<double> c;
double r = (double) rand()/RAND_MAX;
double i = (double) rand()/RAND_MAX;
double rh = std::max(hig.real(), low.real());
double rl = std::min(hig.real(), low.real());
double ih = std::max(hig.imag(), low.imag());
double il = std::min(hig.imag(), low.imag());
c.real(r*(rh - rl) + rl);
c.imag(i*(ih - il) + il);
return c;
}
bool gctl::isequal(double f, double v, double eps)
{
return fabs(f - v) < eps;
}
double gctl::sign(double a)
{
if (a > GCTL_ZERO) return 1.0;
if (a < -1.0*GCTL_ZERO) return -1.0;
return 0.0;
}
//利用二分法求一个正数的n次方根 注意输入值小于1的情况
double gctl::sqrtn(double d,int n,double eps)
{
double xmin,xmax,halfx;
if (d == 1)
{
return d;
}
else if (d > 1)
{
xmin = 1;
xmax = d;
halfx = 0.5*(xmin+xmax);
while (fabs(d - pow(halfx,n)) > eps)
{
if (pow(halfx,n) > d)
{
xmax = halfx;
halfx = 0.5*(xmin+xmax);
}
else
{
xmin = halfx;
halfx = 0.5*(xmin+xmax);
}
}
}
else
{
xmin = 0;
xmax = 1;
halfx = 0.5*(xmin+xmax);
while (fabs(d - pow(halfx,n)) > eps)
{
if (pow(halfx,n) > d)
{
xmax = halfx;
halfx = 0.5*(xmin+xmax);
}
else
{
xmin = halfx;
halfx = 0.5*(xmin+xmax);
}
}
}
return halfx;
}
double gctl::geographic_area(double lon1, double lon2, double lat1, double lat2, double R)
{
return fabs(R*R*(arc(lon2) - arc(lon1))*(sind(lat2) - sind(lat1)));
}
double gctl::geographic_distance(double lon1, double lon2, double lat1, double lat2, double R)
{
double n1 = arc(lon1), n2 = arc(lon2), t1 = arc(lat1), t2 = arc(lat2);
double a = sin(0.5*(t2 - t1)), b = sin(0.5*(n2 - n1));
return 2*R*asin(sqrt(a*a + cos(t1)*cos(t2)*b*b));
}
double gctl::ellipse_radius_2d(double x_len, double y_len, double arc, double x_arc)
{
if (fabs(x_len - y_len) < 1e-16) // 就是个圆 直接加
{
return 0.5*(x_len + y_len);
}
return sqrt(power2(x_len*cos(arc - x_arc)) + power2(y_len*sin(arc - x_arc)));
}
void gctl::ellipse_plus_elevation_2d(double x_len, double y_len, double arc, double elev,
double &out_arc, double &out_rad, double x_arc)
{
if (fabs(x_len - y_len) < 1e-8) // 就是个圆 直接加
{
out_arc = arc;
out_rad = 0.5*(x_len + y_len) + elev;
return;
}
if (fabs(arc) < 1e-8) // 弧度太小 直接加和
{
out_arc = arc;
out_rad = x_len + elev;
return;
}
if (fabs(fabs(arc) - 0.5*GCTL_Pi) < 1e-8) // 到了弧顶 直接加和
{
out_arc = arc;
out_rad = y_len + elev;
return;
}
double ellip_rad = ellipse_radius_2d(x_len, y_len, arc, x_arc);
double alpha = atan(x_len*x_len*sin(arc)/(y_len*y_len*cos(arc)));
double sin_alpha = sin(alpha);
double lx = ellip_rad * sin(alpha - arc)/sin_alpha;
double lr = ellip_rad * sin(arc)/sin_alpha + elev;
out_rad = sqrt(lx*lx + lr*lr - 2.0*lx*lr*cos(GCTL_Pi - alpha));
out_arc = acos((lx*lx + out_rad*out_rad - lr*lr)/(2.0*out_rad*lx));
if (arc < 0.0) out_arc *= -1.0;
return;
}
double gctl::ellipsoid_radius(double x_len, double y_len, double z_len, double phi, double theta)
{
return x_len*y_len*z_len/sqrt(pow(y_len*z_len*sin(theta)*cos(phi),2) +
pow(x_len*z_len*sin(theta)*sin(phi),2) + pow(x_len*y_len*cos(theta),2));
}
// 使用牛顿迭代法计算一个矩阵的近似逆
double gctl::newton_inverse(const _2d_matrix &in_mat, _2d_matrix &inverse_mat,
double epsilon, int iter_times, bool initiate)
{
if (in_mat.empty())
throw runtime_error("The input matrix is empty. Thrown by gctl::newton_inverse(...)");
if (in_mat.row_size() != in_mat.col_size())
throw logic_error("The input matrix is square. Thrown by gctl::newton_inverse(...)");
if (iter_times < 0)
throw invalid_argument("Invalid iteration times. Thrown by gctl::newton_inverse(...)");
int m_size = in_mat.row_size();
if (initiate)
{
// 初始化逆矩阵 使用输入矩阵的对角元素构建初始矩阵
if (!inverse_mat.empty()) inverse_mat.clear();
inverse_mat.resize(m_size, m_size, 0.0);
for (int i = 0; i < m_size; i++)
{
inverse_mat[i][i] = 1.0/in_mat[i][i];
}
}
if (inverse_mat.row_size() != m_size || inverse_mat.col_size() != m_size)
throw logic_error("Invalid output matrix size. From gctl::newton_inverse(...)");
// 迭代的收敛条件 || E - in_mat*inverse_mat ||_inf < 1
// 计算矩阵的无穷大范数
double maxi_mod = 0.0, mod, ele;
for (int i = 0; i < m_size; i++)
{
mod = 0.0;
for (int j = 0; j < m_size; j++)
{
ele = 0.0;
for (int k = 0; k < m_size; k++)
{
ele += in_mat[i][k] * inverse_mat[k][j];
}
if (i == j)
{
mod += GCTL_FABS(1.0 - ele);
}
else
{
mod += GCTL_FABS(ele);
}
}
maxi_mod = GCTL_MAX(maxi_mod, mod);
}
if (maxi_mod >= 1.0)
{
GCTL_ShowWhatError("The iteration may not converge. From gctl::newton_inverse(...)",
GCTL_WARNING_ERROR, 0, 0, 0);
}
array<double> col_ax(m_size, 0.0); // A*X 的列向量
_2d_matrix tmp_mat(m_size, m_size, 0.0);
for (int t = 0; t < iter_times; t++)
{
if (maxi_mod <= epsilon)
break;
for (int i = 0; i < m_size; i++)
{
for (int j = 0; j < m_size; j++)
{
tmp_mat[i][j] = inverse_mat[i][j];
}
}
for (int n = 0; n < m_size; n++)
{
for (int i = 0; i < m_size; i++)
{
for (int j = 0; j < m_size; j++)
{
col_ax[j] = 0.0;
for (int k = 0; k < m_size; k++)
{
col_ax[j] += in_mat[j][k] * tmp_mat[k][i];
}
col_ax[j] *= -1.0;
}
col_ax[i] += 2.0;
ele = 0.0;
for (int j = 0; j < m_size; j++)
{
ele += tmp_mat[n][j] * col_ax[j];
}
inverse_mat[n][i] = ele;
}
}
maxi_mod = 0.0;
for (int i = 0; i < m_size; i++)
{
mod = 0.0;
for (int j = 0; j < m_size; j++)
{
ele = 0.0;
for (int k = 0; k < m_size; k++)
{
ele += in_mat[i][k] * inverse_mat[k][j];
}
if (i == j)
{
mod += GCTL_FABS(1.0 - ele);
}
else
{
mod += GCTL_FABS(ele);
}
}
maxi_mod = GCTL_MAX(maxi_mod, mod);
}
}
return maxi_mod;
}
// 使用牛顿迭代法计算一个矩阵的近似逆
double gctl::newton_inverse(const spmat<double> &in_mat, _2d_matrix &inverse_mat,
double epsilon, int iter_times, bool initiate)
{
if (in_mat.empty())
throw runtime_error("The input matrix is empty. Thrown by gctl::newton_inverse(...)");
if (in_mat.row_size() != in_mat.col_size())
throw logic_error("The input matrix is square. Thrown by gctl::newton_inverse(...)");
if (iter_times < 0)
throw invalid_argument("Invalid iteration times. Thrown by gctl::newton_inverse(...)");
int m_size = in_mat.row_size();
if (initiate)
{
// 初始化逆矩阵 使用输入矩阵的对角元素构建初始矩阵
if (!inverse_mat.empty()) inverse_mat.clear();
inverse_mat.resize(m_size, m_size, 0.0);
for (int i = 0; i < m_size; i++)
{
inverse_mat[i][i] = 1.0/in_mat.at(i, i);
}
}
if (inverse_mat.row_size() != m_size || inverse_mat.col_size() != m_size)
throw logic_error("Invalid output matrix size. From gctl::newton_inverse(...)");
// 迭代的收敛条件 || E - in_mat*inverse_mat ||_inf < 1
// 计算矩阵的无穷大范数
double maxi_mod = 0.0, mod, ele;
array<double> tmp_arr(m_size, 0.0); // A*X 的列向量
for (int i = 0; i < m_size; i++)
{
mod = 0.0;
for (int j = 0; j < m_size; j++)
{
for (int k = 0; k < m_size; k++)
{
tmp_arr[k] = inverse_mat[k][j];
}
ele = in_mat.multiply_vector(tmp_arr, i);
if (i == j)
{
mod += GCTL_FABS(1.0 - ele);
}
else
{
mod += GCTL_FABS(ele);
}
}
maxi_mod = GCTL_MAX(maxi_mod, mod);
}
if (maxi_mod >= 1.0)
{
GCTL_ShowWhatError("The iteration may not converge. From gctl::newton_inverse(...)",
GCTL_WARNING_ERROR, 0, 0, 0);
}
array<double> col_ax(m_size, 0.0);
_2d_matrix tmp_mat(m_size, m_size, 0.0);
for (int t = 0; t < iter_times; t++)
{
if (maxi_mod <= epsilon)
break;
//else std::cout << "epsilon = " << maxi_mod << std::endl;
for (int i = 0; i < m_size; i++)
{
for (int j = 0; j < m_size; j++)
{
tmp_mat[i][j] = inverse_mat[i][j];
}
}
for (int n = 0; n < m_size; n++)
{
for (int i = 0; i < m_size; i++)
{
for (int j = 0; j < m_size; j++)
{
for (int k = 0; k < m_size; k++)
{
tmp_arr[k] = tmp_mat[k][i];
}
col_ax[j] = in_mat.multiply_vector(tmp_arr, j);
col_ax[j] *= -1.0;
}
col_ax[i] += 2.0;
ele = 0.0;
for (int j = 0; j < m_size; j++)
{
ele += tmp_mat[n][j] * col_ax[j];
}
inverse_mat[n][i] = ele;
}
}
maxi_mod = 0.0;
for (int i = 0; i < m_size; i++)
{
mod = 0.0;
for (int j = 0; j < m_size; j++)
{
for (int k = 0; k < m_size; k++)
{
tmp_arr[k] = inverse_mat[k][j];
}
ele = in_mat.multiply_vector(tmp_arr, i);
if (i == j)
{
mod += GCTL_FABS(1.0 - ele);
}
else
{
mod += GCTL_FABS(ele);
}
}
maxi_mod = GCTL_MAX(maxi_mod, mod);
}
}
return maxi_mod;
}
void gctl::schmidt_orthogonal(const array<double> &a, array<double> &e, int a_s)
{
if (a.empty())
throw runtime_error("The input array is empty. Thrown by gctl::schmidt_orthogonal(...)");
if (a_s <= 1) // a_s >= 2
throw invalid_argument("vector size must be bigger than one. Thrown by gctl::schmidt_orthogonal(...)");
int t_s = a.size();
if (t_s%a_s != 0 || t_s <= 3) // t_s >= 4
throw invalid_argument("incompatible total array size. Thrown by gctl::schmidt_orthogonal(...)");
int len = t_s/a_s;
if (len < a_s)
throw invalid_argument("the vectors are over-determined. Thrown by gctl::schmidt_orthogonal(...)");
e.resize(t_s, 0.0);
double ae, ee;
for (int i = 0; i < a_s; i++)
{
for (int l = 0; l < len; l++)
{
e[l + i*len] = a[l + i*len];
}
for (int m = 0; m < i; m++)
{
ae = ee = 0.0;
for (int n = 0; n < len; n++)
{
ae += a[n + i*len] * e[n + m*len];
ee += e[n + m*len] * e[n + m*len];
}
for (int n = 0; n < len; n++)
{
e[n + i*len] -= e[n + m*len] * ae/ee;
}
}
}
for (int i = 0; i < a_s; i++)
{
ee = 0.0;
for (int l = 0; l < len; l++)
{
ee += e[l + i*len] * e[l + i*len];
}
ee = sqrt(ee);
for (int l = 0; l < len; l++)
{
e[l + i*len] /= ee;
}
}
return;
}
double gctl::dist_inverse_weight(std::vector<double> *dis_vec, std::vector<double> *val_vec, int order)
{
if (dis_vec->size() != val_vec->size())
throw runtime_error("The arrays have different sizes. Thrown by gctl::dist_inverse_weight(...)");
double total_dist = 0;
for (int i = 0; i < dis_vec->size(); i++)
{
dis_vec->at(i) = 1.0/(GCTL_ZERO + pow(dis_vec->at(i),order));
total_dist += dis_vec->at(i);
}
double ret = 0.0;
for (int i = 0; i < dis_vec->size(); i++)
{
ret += val_vec->at(i)*dis_vec->at(i)/total_dist;
}
return ret;
}
int gctl::find_index(const double *in_array, int array_size, double in_val, int &index)
{
if (array_size <= 0)
{
index = -1;
return -1;
}
else if (array_size == 1)
{
index = -1;
return -1;
}
else if (in_val < in_array[0] || in_val > in_array[array_size-1])
{
index = -1;
return -1;
}
else if (array_size == 2)
{
index = 0;
return 0;
}
else
{
int low_range = 0;
int high_range = array_size - 1;
int test_index;
bool found = false;
while (high_range - low_range >= 1)
{
test_index = floor(0.5*(low_range + high_range));
if (in_val >= in_array[test_index] && in_val <= in_array[test_index+1])
{
index = test_index;
found = true;
break;
}
else if (in_val < in_array[test_index])
{
high_range = test_index;
}
else if (in_val > in_array[test_index+1])
{
low_range = test_index+1;
}
}
if (found) return 0;
else return -1;
}
}
int gctl::find_index(array<double> *in_array, double in_val, int &index)
{
return find_index(in_array->get(), in_array->size(), in_val, index);
}
void gctl::fractal_model_1d(array<double> &out_arr, int out_size, double l_val,
double r_val, double maxi_range, double smoothness)
{
if (out_size <= 0)
throw invalid_argument("Negative output size. Thrown by gctl::fractal_model_1d(...)");
if (maxi_range <= 0)
throw invalid_argument("Negative maximal range. Thrown by gctl::fractal_model_1d(...)");
if (smoothness <= 0)
throw invalid_argument("Negative smoothness. Thrown by gctl::fractal_model_1d(...)");
out_arr.resize(out_size);
int bigger_num = (int) pow(2, ceil(log(out_arr.size()-1)/log(2))) + 1;
array<double> tmp_arr(bigger_num); // 计算的长度必须为2的次方数
int step_size = (int) (bigger_num-1)/2;
tmp_arr[0] = l_val;
tmp_arr[bigger_num-1] = r_val;
srand(time(0));
while (step_size >= 1)
{
for (int i = step_size; i < bigger_num; i += 2*step_size)
{
tmp_arr[i] = random(-1.0*maxi_range, maxi_range) +
0.5*(tmp_arr[i-step_size] + tmp_arr[i+step_size]);
}
maxi_range = pow(2.0, -1.0*smoothness)*maxi_range;
step_size /= 2;
}
for (int i = 0; i < out_arr.size(); i++)
{
out_arr[i] = tmp_arr[i];
}
return;
}
void gctl::fractal_model_2d(_2d_matrix &out_arr, int r_size, int c_size, double dl_val,
double dr_val, double ul_val, double ur_val, double maxi_range, double smoothness,
unsigned int seed)
{
if (r_size <= 0 || c_size <= 0)
throw invalid_argument("Negative output size. Thrown by gctl::fractal_model_2d(...)");
if (maxi_range <= 0)
throw invalid_argument("Negative maximal range. Thrown by gctl::fractal_model_2d(...)");
if (smoothness <= 0)
throw invalid_argument("Negative smoothness. Thrown by gctl::fractal_model_2d(...)");
int i, j, m, n, R, jmax;
double random_d;
out_arr.resize(r_size, c_size);
int xnum = out_arr.col_size();
int ynum = out_arr.row_size();
int order_x = ceil(log(xnum-1)/log(2));
int order_y = ceil(log(ynum-1)/log(2));
int imax = GCTL_MAX(order_x,order_y);
int ntotal = (int) pow(2.0, imax) + 1; //总数据点数为2的imax次方加1
_2d_matrix topo(ntotal, ntotal, 0.0);
for (i=0; i<ntotal; i++)//设定地形数据初始值,角点数据必须给出
{
for (j=0; j<ntotal; j++)
{
if (i == 0 && j == 0)
{
topo[i][j] = ul_val; //角点初始值;
}
else if (i == ntotal-1 && j==0)
{
topo[i][j] = dl_val; //角点初始值;
}
else if (i==0 && j==ntotal-1)
{
topo[i][j] = ur_val; //角点初始值;
}
else if (i==ntotal-1 && j==ntotal-1)
{
topo[i][j] = dr_val; //角点初始值;
}
else
{
topo[i][j] = GCTL_BDL_MAX;
}
}
}
if (seed == 0) srand(time(0));
else srand(seed);
for (i = 1; i <= imax; i++)//开始迭代,生成正方形区域随机地形
{
R = int(double(ntotal-1)/pow(2.0,i));
jmax=int(pow(4.0,i-1));
for (j=1; j<=jmax; j++)
{
random_d = random(-1.0*maxi_range, maxi_range);
m=2*R*(j-(ceil((double)j/pow(2.0,i-1))-1) * pow(2.0,i-1))-R;
n=2*R*(ceil((double)j/pow(2.0,i-1)))-R;
topo[m][n]=(topo[m-R][n-R]+topo[m+R][n-R]+topo[m-R][n+R]+topo[m+R][n+R])/4+random_d;
}
for (j=1; j<=jmax; j++)
{
m=2*R*(j-(ceil((double)j/pow(2.0,i-1))-1)* pow(2.0,i-1))-R;
n=2*R*(ceil((double)j/pow(2.0,i-1)))-R;
if (topo[m][n-R] == GCTL_BDL_MAX)
{
random_d = random(-1.0*maxi_range, maxi_range);
if ((n-R)!=0)
{
topo[m][n-R]=(topo[m][n-2*R]+topo[m-R][n-R]+topo[m+R][n-R]+topo[m][n])/4+random_d;
}
else
{
topo[m][n-R]=(topo[m-R][n-R]+topo[m+R][n-R]+topo[m][n])/3+random_d;
}
}
if (topo[m-R][n] == GCTL_BDL_MAX)
{
random_d = random(-1.0*maxi_range, maxi_range);
if ((m-R)!=0)
{
topo[m-R][n]=(topo[m-R][n-R]+topo[m-2*R][n]+topo[m][n]+topo[m-R][n+R])/4+random_d;
}
else
{
topo[m-R][n]=(topo[m-R][n-R]+topo[m][n]+topo[m-R][n+R])/3+random_d;
}
}
if (topo[m+R][n] == GCTL_BDL_MAX)
{
random_d = random(-1.0*maxi_range, maxi_range);
if ((m+R)!=(ntotal-1))
{
topo[m+R][n]=(topo[m+R][n-R]+topo[m][n]+topo[m+2*R][n]+topo[m+R][n+R])/4+random_d;
}
else
{
topo[m+R][n]=(topo[m+R][n-R]+topo[m][n]+topo[m+R][n+R])/3+random_d;
}
}
if (topo[m][n+R] == GCTL_BDL_MAX)
{
random_d = random(-1.0*maxi_range, maxi_range);
if ((n+R)!=(ntotal-1))
{
topo[m][n+R]=(topo[m][n]+topo[m-R][n+R]+topo[m+R][n+R]+topo[m][n+2*R])/4+random_d;
}
else
{
topo[m][n+R]=(topo[m][n]+topo[m-R][n+R]+topo[m+R][n+R])/3+random_d;
}
}
}
maxi_range = pow(2.0, -1.0*smoothness)*maxi_range;
}
for (int j = 0; j < ynum; j++)//按预设区域剪裁数组
{
for (int i=0; i < xnum; i++)
{
out_arr[i][j] = topo[i][j];
}
}
return;
}
void gctl::difference_1d(const array<double> &in, array<double> &diff, double spacing, int order)
{
if (order < 1 || order > 4)
throw invalid_argument("The input order can only be 1 to 4. Thrown by gctl::difference_1d(...)");
if (spacing <= 0.0)
throw invalid_argument("The input spacing can't be negative or zero. Thrown by void gctl::difference_1d(...)");
if (order == 1 && in.size() < 3)
throw runtime_error("The input array size must be equal to or bigger than three for the first order derivative. Thrown by gctl::difference_1d(...)");
if (order == 2 && in.size() < 4)
throw runtime_error("The input array size must be equal to or bigger than four for the second order derivative. Thrown by gctl::difference_1d(...)");
if (order == 3 && in.size() < 6)
throw runtime_error("The input array size must be equal to or bigger than six for the third order derivative. Thrown by gctl::difference_1d(...)");
if (order == 4 && in.size() < 7)
throw runtime_error("The input array size must be equal to or bigger than seven for the fourth order derivative. Thrown by gctl::difference_1d(...)");
int t_size = in.size();
diff.resize(t_size);
// 利用向前或向后差分计算边缘元素的导数
if (order == 1)
{
diff[0] = (-3.0*in[0]+4.0*in[1]-in[2])/(2.0*spacing);
diff[t_size-1] = (3.0*in[t_size-1]-4.0*in[t_size-2]+in[t_size-3])/(2.0*spacing);
for (int i = 1; i < t_size-1; i++)
{
diff[i] = (in[i+1] - in[i-1])/(2.0*spacing);
}
}
else if (order == 2)
{
diff[0] = (2.0*in[0]-5.0*in[1]+4.0*in[2]-in[3])/(spacing*spacing);
diff[t_size-1] = (2.0*in[t_size-1]-5.0*in[t_size-2]+4.0*in[t_size-3]-in[t_size-4])/(spacing*spacing);
for (int i = 1; i < t_size-1; i++)
{
diff[i] = (in[i-1]-2.0*in[i]+in[i+1])/(spacing*spacing);
}
}
else if (order == 3)
{
diff[0] = (-5.0*in[0]+18.0*in[1]-24.0*in[2]+14.0*in[3]-3.0*in[4])/(2.0*spacing*spacing*spacing);
diff[1] = (-5.0*in[1]+18.0*in[2]-24.0*in[3]+14.0*in[4]-3.0*in[5])/(2.0*spacing*spacing*spacing);
diff[t_size-1] = (5.0*in[t_size-1]-18.0*in[t_size-2]+24.0*in[t_size-3]-14.0*in[t_size-4]+3.0*in[t_size-5])/(2.0*spacing*spacing*spacing);
diff[t_size-2] = (5.0*in[t_size-2]-18.0*in[t_size-3]+24.0*in[t_size-4]-14.0*in[t_size-5]+3.0*in[t_size-6])/(2.0*spacing*spacing*spacing);
for (int i = 2; i < t_size-2; i++)
{
diff[i] = (-1.0*in[i-2]+2.0*in[i-1]-2.0*in[i+1]+in[i+2])/(2.0*spacing*spacing*spacing);
}
}
else
{
diff[0] = (3.0*in[0]-14.0*in[1]+26.0*in[2]-24.0*in[3]+11.0*in[4]-2.0*in[5])/(spacing*spacing*spacing*spacing);
diff[1] = (3.0*in[1]-14.0*in[2]+26.0*in[3]-24.0*in[4]+11.0*in[5]-2.0*in[6])/(spacing*spacing*spacing*spacing);
diff[t_size-1] = (3.0*in[t_size-1]-14.0*in[t_size-2]+26.0*in[t_size-3]-24.0*in[t_size-4]+11.0*in[t_size-5]-2.0*in[t_size-6])/(spacing*spacing*spacing*spacing);
diff[t_size-2] = (3.0*in[t_size-2]-14.0*in[t_size-3]+26.0*in[t_size-4]-24.0*in[t_size-5]+11.0*in[t_size-6]-2.0*in[t_size-7])/(spacing*spacing*spacing*spacing);
for (int i = 2; i < t_size-2; i++)
{
diff[i] = (in[i-2]-4.0*in[i-1]+6.0*in[i]-4.0*in[i+1]+in[i+2])/(spacing*spacing*spacing*spacing);
}
}
return;
}
void gctl::difference_2d(const _2d_matrix &in, _2d_matrix &diff, double spacing, gradient_type_e d_type, int order)
{
std::string err_str;
if (order < 1 || order > 4)
throw invalid_argument("The input order can only be 1 to 4. Thrown by void gctl::difference_2d(...)");
if (spacing <= 0.0)
throw invalid_argument("The input spacing can't be negative or zero. Thrown by void gctl::difference_2d(...)");
int t_size;
if (d_type == Dx)
{
t_size = in.col_size();
}
else if (d_type == Dy)
{
t_size = in.row_size();
}
else
{
throw logic_error("The calculation type must be Dx or Dy. Thrown by gctl::difference_2d(...)");
}
if (order == 1 && t_size < 3)
throw runtime_error("The input array size must be equal to or bigger than 3x3 for the first order derivative. Thrown by void gctl::difference_2d(...)");
if (order == 2 && t_size < 4)
throw runtime_error("The input array size must be equal to or bigger than 4x4 for the second order derivative. Thrown by gctl::difference_2d(...)");
if (order == 3 && t_size < 6)
throw runtime_error("The input array size must be equal to or bigger than 6x6 for the third order derivative. Thrown by gctl::difference_2d(...)");
if (order == 4 && t_size < 7)
throw runtime_error("The input array size must be equal to or bigger than 7x7 for the fourth order derivative. Thrown by void gctl::difference_2d(...)");
int tr_size = in.row_size(), tl_size = in.col_size();
diff.resize(tr_size, tl_size);
if (d_type == Dx)
{
if (order == 1)
{
for (int i = 0; i < tr_size; i++)
{
diff[i][0] = (-3.0*in[i][0]+4.0*in[i][1]-in[i][2])/(2.0*spacing);
diff[i][tl_size-1] = (3.0*in[i][tl_size-1]-4.0*in[i][tl_size-2]+in[i][tl_size-3])/(2.0*spacing);
for (int j = 1; j < tl_size-1; j++)
{
diff[i][j] = (in[i][j+1] - in[i][j-1])/(2.0*spacing);
}
}
}
else if (order == 2)
{
for (int i = 0; i < tr_size; i++)
{
diff[i][0] = (2.0*in[i][0]-5.0*in[i][1]+4.0*in[i][2]-in[i][3])/(spacing*spacing);
diff[i][tl_size-1] = (2.0*in[i][tl_size-1]-5.0*in[i][tl_size-2]+4.0*in[i][tl_size-3]-in[i][tl_size-4])/(spacing*spacing);
for (int j = 1; j < tl_size-1; j++)
{
diff[i][j] = (in[i][j-1]-2.0*in[i][j]+in[i][j+1])/(spacing*spacing);
}
}
}
else if (order == 3)
{
for (int i = 0; i < tr_size; i++)
{
diff[i][0] = (-5.0*in[i][0]+18.0*in[i][1]-24.0*in[i][2]+14.0*in[i][3]-3.0*in[i][4])/(2.0*spacing*spacing*spacing);
diff[i][1] = (-5.0*in[i][1]+18.0*in[i][2]-24.0*in[i][3]+14.0*in[i][4]-3.0*in[i][5])/(2.0*spacing*spacing*spacing);
diff[i][tl_size-1] = (5.0*in[i][tl_size-1]-18.0*in[i][tl_size-2]+24.0*in[i][tl_size-3]-14.0*in[i][tl_size-4]+3.0*in[i][tl_size-5])/(2.0*spacing*spacing*spacing);
diff[i][tl_size-2] = (5.0*in[i][tl_size-2]-18.0*in[i][tl_size-3]+24.0*in[i][tl_size-4]-14.0*in[i][tl_size-5]+3.0*in[i][tl_size-6])/(2.0*spacing*spacing*spacing);
for (int j = 2; j < tl_size-2; j++)
{
diff[i][j] = (-1.0*in[i][j-2]+2.0*in[i][j-1]-2.0*in[i][j+1]+in[i][j+2])/(2.0*spacing*spacing*spacing);
}
}
}
else
{
for (int i = 0; i < tr_size; i++)
{
diff[i][0] = (3.0*in[i][0]-14.0*in[i][1]+26.0*in[i][2]-24.0*in[i][3]+11.0*in[i][4]-2.0*in[i][5])/(spacing*spacing*spacing*spacing);
diff[i][1] = (3.0*in[i][1]-14.0*in[i][2]+26.0*in[i][3]-24.0*in[i][4]+11.0*in[i][5]-2.0*in[i][6])/(spacing*spacing*spacing*spacing);
diff[i][tl_size-1] = (3.0*in[i][tl_size-1]-14.0*in[i][tl_size-2]+26.0*in[i][tl_size-3]-24.0*in[i][tl_size-4]+11.0*in[i][tl_size-5]-2.0*in[i][tl_size-6])/(spacing*spacing*spacing*spacing);
diff[i][tl_size-2] = (3.0*in[i][tl_size-2]-14.0*in[i][tl_size-3]+26.0*in[i][tl_size-4]-24.0*in[i][tl_size-5]+11.0*in[i][tl_size-6]-2.0*in[i][tl_size-7])/(spacing*spacing*spacing*spacing);
for (int j = 2; j < tl_size-2; j++)
{
diff[i][j] = (in[i][j-2]-4.0*in[i][j-1]+6.0*in[i][j]-4.0*in[i][j+1]+in[i][j+2])/(spacing*spacing*spacing*spacing);
}
}
}
}
else
{
if (order == 1)
{
for (int j = 0; j < tl_size; j++)
{
diff[0][j] = (-3.0*in[0][j]+4.0*in[1][j]-in[2][j])/(2.0*spacing);
diff[tr_size-1][j] = (3.0*in[tr_size-1][j]-4.0*in[tr_size-2][j]+in[tr_size-3][j])/(2.0*spacing);
for (int i = 1; i < tr_size-1; i++)
{
diff[i][j] = (in[i+1][j] - in[i-1][j])/(2.0*spacing);
}
}
}
else if (order == 2)
{
for (int j = 0; j < tl_size; j++)
{
diff[0][j] = (2.0*in[0][j]-5.0*in[1][j]+4.0*in[2][j]-in[3][j])/(spacing*spacing);
diff[tr_size-1][j] = (2.0*in[tr_size-1][j]-5.0*in[tr_size-2][j]+4.0*in[tr_size-3][j]-in[tr_size-4][j])/(spacing*spacing);
for (int i = 1; i < tr_size-1; i++)
{
diff[i][j] = (in[i-1][j]-2.0*in[i][j]+in[i+1][j])/(spacing*spacing);
}
}
}
else if (order == 3)
{
for (int j = 0; j < tl_size; j++)
{
diff[0][j] = (-5.0*in[0][j]+18.0*in[1][j]-24.0*in[2][j]+14.0*in[3][j]-3.0*in[4][j])/(2.0*spacing*spacing*spacing);
diff[1][j] = (-5.0*in[1][j]+18.0*in[2][j]-24.0*in[3][j]+14.0*in[4][j]-3.0*in[5][j])/(2.0*spacing*spacing*spacing);
diff[tr_size-1][j] = (5.0*in[tr_size-1][j]-18.0*in[tr_size-2][j]+24.0*in[tr_size-3][j]-14.0*in[tr_size-4][j]+3.0*in[tr_size-5][j])/(2.0*spacing*spacing*spacing);
diff[tr_size-2][j] = (5.0*in[tr_size-2][j]-18.0*in[tr_size-3][j]+24.0*in[tr_size-4][j]-14.0*in[tr_size-5][j]+3.0*in[tr_size-6][j])/(2.0*spacing*spacing*spacing);
for (int i = 2; i < tr_size-2; i++)
{
diff[i][j] = (-1.0*in[i-2][j]+2.0*in[i-1][j]-2.0*in[i+1][j]+in[i+2][j])/(2.0*spacing*spacing*spacing);
}
}
}
else
{
for (int j = 0; j < tl_size; j++)
{
diff[0][j] = (3.0*in[0][j]-14.0*in[1][j]+26.0*in[2][j]-24.0*in[3][j]+11.0*in[4][j]-2.0*in[5][j])/(spacing*spacing*spacing*spacing);
diff[1][j] = (3.0*in[1][j]-14.0*in[2][j]+26.0*in[3][j]-24.0*in[4][j]+11.0*in[5][j]-2.0*in[6][j])/(spacing*spacing*spacing*spacing);
diff[tr_size-1][j] = (3.0*in[tr_size-1][j]-14.0*in[tr_size-2][j]+26.0*in[tr_size-3][j]-24.0*in[tr_size-4][j]+11.0*in[tr_size-5][j]-2.0*in[tr_size-6][j])/(spacing*spacing*spacing*spacing);
diff[tr_size-2][j] = (3.0*in[tr_size-2][j]-14.0*in[tr_size-3][j]+26.0*in[tr_size-4][j]-24.0*in[tr_size-5][j]+11.0*in[tr_size-6][j]-2.0*in[tr_size-7][j])/(spacing*spacing*spacing*spacing);
for (int i = 2; i < tr_size-2; i++)
{
diff[i][j] = (in[i-2][j]-4.0*in[i-1][j]+6.0*in[i][j]-4.0*in[i+1][j]+in[i+2][j])/(spacing*spacing*spacing*spacing);
}
}
}
}
return;
}
void gctl::difference_2d(const array<double> &in, array<double> &diff, int row_size, int col_size,
double spacing, gradient_type_e d_type, int order)
{
std::string err_str;
if (order < 1 || order > 4)
throw invalid_argument("The input order can only be 1 to 4. Thrown by void gctl::difference_2d(...)");
if (spacing <= 0.0)
throw invalid_argument("The input spacing can't be negative or zero. Thrown by void gctl::difference_2d(...)");
if (row_size*col_size != in.size())
throw invalid_argument("The input array size does not match. Thrown by void gctl::difference_2d(...)");
int t_size;
if (d_type == Dx)
{
t_size = col_size;
}
else if (d_type == Dy)
{
t_size = row_size;
}
else
{
throw logic_error("The calculation type must be Dx or Dy. Thrown by gctl::difference_2d(...)");
}
if (order == 1 && t_size < 3)
throw runtime_error("The input array size must be equal to or bigger than 3x3 for the first order derivative. Thrown by gctl::difference_2d(...)");
if (order == 2 && t_size < 4)
throw runtime_error("The input array size must be equal to or bigger than 4x4 for the second order derivative. Thrown by gctl::difference_2d(...)");
if (order == 3 && t_size < 6)
throw runtime_error("The input array size must be equal to or bigger than 6x6 for the third order derivative. Thrown by gctl::difference_2d(...)");
if (order == 4 && t_size < 7)
throw runtime_error("The input array size must be equal to or bigger than 7x7 for the fourth order derivative. Thrown by gctl::difference_2d(...)");
int tr_size = row_size, tl_size = col_size;
diff.resize(tr_size*tl_size);
int idx;
if (d_type == Dx)
{
if (order == 1)
{
for (int i = 0; i < tr_size; i++)
{
idx = i*tl_size;
diff[idx] = (-3.0*in[idx]+4.0*in[idx+1]-in[idx+2])/(2.0*spacing);
idx = i*tl_size + tl_size-1;
diff[idx] = (3.0*in[idx]-4.0*in[idx-1]+in[idx-2])/(2.0*spacing);
for (int j = 1; j < tl_size-1; j++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx+1] - in[idx-1])/(2.0*spacing);
}
}
}
else if (order == 2)
{
for (int i = 0; i < tr_size; i++)
{
idx = i*tl_size;
diff[idx] = (2.0*in[idx]-5.0*in[idx+1]+4.0*in[idx+2]-in[idx+3])/(spacing*spacing);
idx = i*tl_size + tl_size-1;
diff[idx] = (2.0*in[idx]-5.0*in[idx-1]+4.0*in[idx-2]-in[idx-3])/(spacing*spacing);
for (int j = 1; j < tl_size-1; j++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx-1]-2.0*in[idx]+in[idx+1])/(spacing*spacing);
}
}
}
else if (order == 3)
{
for (int i = 0; i < tr_size; i++)
{
idx = i*tl_size;
diff[idx] = (-5.0*in[idx]+18.0*in[idx+1]-24.0*in[idx+2]+14.0*in[idx+3]-3.0*in[idx+4])/(2.0*spacing*spacing*spacing);
idx = i*tl_size+1;
diff[idx] = (-5.0*in[idx]+18.0*in[idx+1]-24.0*in[idx+2]+14.0*in[idx+3]-3.0*in[idx+4])/(2.0*spacing*spacing*spacing);
idx = i*tl_size + tl_size-1;
diff[idx] = (5.0*in[idx]-18.0*in[idx-1]+24.0*in[idx-2]-14.0*in[idx-3]+3.0*in[idx-4])/(2.0*spacing*spacing*spacing);
idx = i*tl_size + tl_size-2;
diff[idx] = (5.0*in[idx]-18.0*in[idx-1]+24.0*in[idx-2]-14.0*in[idx-3]+3.0*in[idx-4])/(2.0*spacing*spacing*spacing);
for (int j = 2; j < tl_size-2; j++)
{
idx = i*tl_size + j;
diff[idx] = (-1.0*in[idx-2]+2.0*in[idx-1]-2.0*in[idx+1]+in[idx+2])/(2.0*spacing*spacing*spacing);
}
}
}
else
{
for (int i = 0; i < tr_size; i++)
{
idx = i*tl_size;
diff[idx] = (3.0*in[idx]-14.0*in[idx+1]+26.0*in[idx+2]-24.0*in[idx+3]+11.0*in[idx+4]-2.0*in[idx+5])/(spacing*spacing*spacing*spacing);
idx = i*tl_size+1;
diff[idx] = (3.0*in[idx]-14.0*in[idx+1]+26.0*in[idx+2]-24.0*in[idx+3]+11.0*in[idx+4]-2.0*in[idx+5])/(spacing*spacing*spacing*spacing);
idx = i*tl_size + tl_size-1;
diff[idx] = (3.0*in[idx]-14.0*in[idx-1]+26.0*in[idx-2]-24.0*in[idx-3]+11.0*in[idx-4]-2.0*in[idx-5])/(spacing*spacing*spacing*spacing);
idx = i*tl_size + tl_size-2;
diff[idx] = (3.0*in[idx]-14.0*in[idx-1]+26.0*in[idx-2]-24.0*in[idx-3]+11.0*in[idx-4]-2.0*in[idx-5])/(spacing*spacing*spacing*spacing);
for (int j = 2; j < tl_size-2; j++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx-2]-4.0*in[idx-1]+6.0*in[idx]-4.0*in[idx+1]+in[idx+2])/(spacing*spacing*spacing*spacing);
}
}
}
}
else
{
if (order == 1)
{
for (int j = 0; j < tl_size; j++)
{
idx = j;
diff[idx] = (-3.0*in[idx]+4.0*in[idx+tl_size]-in[idx+2*tl_size])/(2.0*spacing);
idx = (tr_size-1)*tl_size + j;
diff[idx] = (3.0*in[idx]-4.0*in[idx-tl_size]+in[idx-2*tl_size])/(2.0*spacing);
for (int i = 1; i < tr_size-1; i++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx+tl_size] - in[idx-tl_size])/(2.0*spacing);
}
}
}
else if (order == 2)
{
for (int j = 0; j < tl_size; j++)
{
idx = j;
diff[idx] = (2.0*in[idx]-5.0*in[idx+tl_size]+4.0*in[idx+2*tl_size]-in[idx+3*tl_size])/(spacing*spacing);
idx = (tr_size-1)*tl_size + j;
diff[idx] = (2.0*in[idx]-5.0*in[idx-tl_size]+4.0*in[idx-2*tl_size]-in[idx-3*tl_size])/(spacing*spacing);
for (int i = 1; i < tr_size-1; i++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx-tl_size]-2.0*in[idx]+in[idx+tl_size])/(spacing*spacing);
}
}
}
else if (order == 3)
{
for (int j = 0; j < tl_size; j++)
{
idx = j;
diff[idx] = (-5.0*in[idx]+18.0*in[idx+tl_size]-24.0*in[idx+2*tl_size]+14.0*in[idx+3*tl_size]-3.0*in[idx+4*tl_size])/(2.0*spacing*spacing*spacing);
idx = tl_size+j;
diff[idx] = (-5.0*in[idx]+18.0*in[idx+tl_size]-24.0*in[idx+2*tl_size]+14.0*in[idx+3*tl_size]-3.0*in[idx+4*tl_size])/(2.0*spacing*spacing*spacing);
idx = (tr_size-1)*tl_size + j;
diff[idx] = (5.0*in[idx]-18.0*in[idx-tl_size]+24.0*in[idx-2*tl_size]-14.0*in[idx-3*tl_size]+3.0*in[idx-4*tl_size])/(2.0*spacing*spacing*spacing);
idx = (tr_size-2)*tl_size + j;
diff[idx] = (5.0*in[idx]-18.0*in[idx-tl_size]+24.0*in[idx-2*tl_size]-14.0*in[idx-3*tl_size]+3.0*in[idx-4*tl_size])/(2.0*spacing*spacing*spacing);
for (int i = 2; i < tr_size-2; i++)
{
idx = i*tl_size + j;
diff[idx] = (-1.0*in[idx-2*tl_size]+2.0*in[idx-tl_size]-2.0*in[idx+tl_size]+in[idx+2*tl_size])/(2.0*spacing*spacing*spacing);
}
}
}
else
{
for (int j = 0; j < tl_size; j++)
{
idx = j;
diff[idx] = (3.0*in[idx]-14.0*in[idx+tl_size]+26.0*in[idx+2*tl_size]-24.0*in[idx+3*tl_size]+11.0*in[idx+4*tl_size]-2.0*in[idx+5*tl_size])/(spacing*spacing*spacing*spacing);
idx = tl_size+j;
diff[idx] = (3.0*in[idx]-14.0*in[idx+tl_size]+26.0*in[idx+2*tl_size]-24.0*in[idx+3*tl_size]+11.0*in[idx+4*tl_size]-2.0*in[idx+5*tl_size])/(spacing*spacing*spacing*spacing);
idx = (tr_size-1)*tl_size + j;
diff[idx] = (3.0*in[idx]-14.0*in[idx-tl_size]+26.0*in[idx-2*tl_size]-24.0*in[idx-3*tl_size]+11.0*in[idx-4*tl_size]-2.0*in[idx-5*tl_size])/(spacing*spacing*spacing*spacing);
idx = (tr_size-2)*tl_size + j;
diff[idx] = (3.0*in[idx]-14.0*in[idx-tl_size]+26.0*in[idx-2*tl_size]-24.0*in[idx-3*tl_size]+11.0*in[idx-4*tl_size]-2.0*in[idx-5*tl_size])/(spacing*spacing*spacing*spacing);
for (int i = 2; i < tr_size-2; i++)
{
idx = i*tl_size + j;
diff[idx] = (in[idx-2*tl_size]-4.0*in[idx-tl_size]+6.0*in[idx]-4.0*in[idx+tl_size]+in[idx+2*tl_size])/(spacing*spacing*spacing*spacing);
}
}
}
}
return;
}