I have a c++ ready code here
// Example program
#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <map>
typedef std::map<int, std::vector<double> > matr_t;
std::vector<double> generateRowVector(std::vector<double> absci_, int row_no, int size_of_matr)
{
std::vector<double> x;
int size_of_vec = absci_.size();
for (int i = 0; i < size_of_matr; ++i)
{
{
double sum = 0;
for (int j = 0; j < size_of_vec; ++j)
{
sum += pow(absci_[j], i + row_no - 1);
}
x.push_back(sum);
}
}
return x;
}
std::vector<double> generateColumnVector(std::vector<double> absci_, std::vector<double> ordi_, int size_of_col)
{
unsigned int size_of_vec = absci_.size();
std::vector<double> y;
if (size_of_vec == ordi_.size())
{
for (int col_no = 1; col_no <= size_of_col; ++col_no)
{
double sum = 0;
for (unsigned int i = 0; i < size_of_vec; ++i)
{
sum += pow(absci_[i], col_no - 1) * ordi_[i];
}
y.push_back(sum);
}
return y;
}
return (std::vector<double>){0,0,0};
}
double getDeterminant(std::map<int, std::vector<double> > matrix, int size_of_matr)
{
double minuend= 0, subtra = 0;
for (int i = 0; i < size_of_matr; ++i)
{
double sum = 1;
for (int row = 1; row <= size_of_matr; ++row)
{
std::cout << matrix[row][(row+i-1) % size_of_matr] << " ";
sum *= matrix[row][(row+i-1) % size_of_matr];
}
minuend += sum;
std::cout << "\n";
}
for (int i = size_of_matr; i > 0; --i)
{
double sum = 1;
for (int row = 1; row <= size_of_matr; ++row)
{
std::cout << "place" << (i-row + size_of_matr)% size_of_matr << ":" << matrix[row][(i-row + size_of_matr) % size_of_matr] << " ";
sum *= matrix[row][(i-row + size_of_matr) % size_of_matr];
}
subtra += sum;
std::cout << "\n";
}
std::cout << "\n";
return minuend - subtra;
}
void EliminateNthElementMthRow(matr_t& matrix_, int element_no, int row_no)
{
double eliminator = matrix_[row_no][element_no-1]/ matrix_[element_no][element_no-1];
int size_of_matrix = matrix_[1].size();
for (int i = 0; i < size_of_matrix; ++i)
{
matrix_[row_no][i] = matrix_[row_no][i] - (eliminator * matrix_[element_no][i]);
}
}
double getDeterminantViaUpperMatrix(matr_t matrix, int size_of_matr)
{
matr_t copyMatr = getUpperMatrix(matrix, size_of_matr);
double det = 1;
for (int i = 1; i <= size_of_matr; ++i)
{
det *= copyMatr[i][i-1];
}
return det;
}
matr_t getUpperMatrix(matr_t matrix_, int size_of_matr)
{
matr_t copyMatr = matrix_;
for (int i = 1; i < size_of_matr; ++i)
{
for (int j = i+1; j <= size_of_matr; ++j)
{
EliminateNthElementMthRow(copyMatr, i, j);
}
}
return copyMatr;
}
matr_t getLowerMatrix(matr_t matrix_)
{
}
matr_t generateIdentityMatr(int size_of_matr)
{
matr_t identity_mat;
for (int i = 1; i <= size_of_matr; ++i )
{
for (int j = 1; j <= size_of_matr; ++j)
{
if (i == j) identity_mat[i].push_back(1);
else identity_mat[i].push_back(0);
}
}
return identity_mat;
}
matr_t getInverseMatrix(matr_t matrix_, int size_of_matr)
{
matr_t identity_mat = generateIdentityMatr(int size_of_matr);
matr_t copyMatr = matrix_;
for (int i = 1; i<= size_of_matr; ++i)
{
copyMatr[i].insert(copyMatr[i].end(), identity_mat[i].begin(), identity_mat[i].end());
}
return copyMatr;
}
int main()
{
int size_of_matr = 3;
std::vector<double> absci({0,0.5,1,1.5,2,2.5});
std::vector<double> ordi({0, 0.25, 1, 2.25, 4, 6.25});
std::vector<double> y = generateColumnVector(absci, ordi, size_of_matr);
std::map<int, std::vector<double> > coeffMat;
for (int row_no = 1; row_no <= size_of_matr; ++row_no)
{
coeffMat[row_no] = generateRowVector(absci, row_no, size_of_matr);
for (auto const& data : coeffMat[row_no] )
{
std::cout << data << " ";
}
std::cout<<"\n";
}
std::cout<<"\n";
for (auto const& data : y)
{
std::cout << data << "\n";
}
std::cout<<"\n";
std::cout << getDeterminant(coeffMat, size_of_matr);
}
This is the procedure
Step 1: Calculate the mean of the xx-values and the mean of the yy-values.
X¯¯¯=∑i=1nxinY¯¯¯=∑i=1nyinX¯=∑i=1nxinY¯=∑i=1nyin
Step 2: The following formula gives the slope of the line of best fit:
m=∑i=1n(xi−X¯¯¯)(yi−Y¯¯¯)∑i=1n(xi−X¯¯¯)2m=∑i=1n(xi−X¯)(yi−Y¯)∑i=1n(xi−X¯)2
Step 3: Compute the yy-intercept of the line by using the formula:
b=Y¯¯¯−mX¯¯¯b=Y¯−mX¯
Step 4: Use the slope mm and the yy-intercept bb to form the equation of the line.
