solve_henon_eqs.c

/*------------------------------------------------------------------------

エノン写像とヤコビ行列（線形化したエノン写像）

Henon map and the Jacobian matrix (linearized Henon map)

solve_henon_eqs.c

------------------------------------------------------------------------*/

#include "henon_lyap.h"

void henon_eqs( double (*x), double (*y), double dfQ[DIM][DIM], double Q[DIM][DIM] )

{

int i, j, k;

double xx;

double yy;

double d2;

double df[DIM][DIM]; // ヤコビ行列, Jacobian matrix

// エノン写像

// Henon map

xx = 1.0 - A * (*x) * (*x) + (*y);

yy = B * (*x);

(*x) = xx;

(*y) = yy;

// ヤコビ行列

// Jacobian matrix

df[0][0] = -2.0 * A * (*x);

df[0][1] = 1.0;

df[1][0] = B;

df[1][1] = 0.0;

/*

｜ df[0][0] df[0][1] ｜

df = ｜ ｜

｜ df[1][0] df[1][1] ｜

*/

// ヤコビ行列dfと行列Qの積dfQの計算

// calculate the product dfQ of the Jacobian matrix df and the matrix Q

for ( i = 0; i < DIM; i++ ) {

for ( j = 0; j < DIM; j++ ) {

d2 = 0.0;

for ( k = 0; k < DIM; k++ ) {

d2 += df[i][k] * Q[k][j];

}

dfQ[i][j] = d2;

}

}

}