int Steepest_Descent(double (*f)(double *), void (*df)(double *, double *),
int (*stopping_rule)(double*, double, double*, double, double*, int, int),
double a[], double *fa, double *dfa, double cutoff,
double cutoff_scale_factor, double tolerance, int n)
{
double* x;
double* initial_a = a;
double* tmp;
double fx;
double p;
int err = 0;
int iteration = 0;
x = (double *) malloc(n * sizeof(double));
if ( x == NULL) { err = -4; }
df(a, dfa);
if (Vector_Max_Norm(dfa,n) == 0.0) err = -5;
while (!err) {
//printf("xMin = (%f , %f) \nf(xMin) = %f\n", a[0], a[1], *fa );
if (Vector_Max_Norm(dfa,n) == 0.0) break;
err = Minimize_Down_the_Line(f, a, *fa, &p, dfa, x, cutoff,
cutoff_scale_factor, tolerance, n);
if ( err ) break;
fx = f(x);
iteration++;
df(x, dfa);
err = stopping_rule( a, *fa, x, fx, dfa, iteration, n);
*fa = fx;
tmp = a;
a = x;
x = tmp;
}
if (a != initial_a ) {
Copy_Vector(initial_a, a, n);
x = a;
}
free(x);
return err;
}
//---------------------------------------------------------
template <class T> double * CSG_mRMR::Get_JointProb(T * img1, T * img2, long len, long maxstatenum, int &nstate1, int &nstate2)
{
long i, j;
//-----------------------------------------------------
// get and check size information
if (!img1 || !img2 || len < 0)
{
SG_UI_Msg_Add_Error("At least one of the input vectors is invalid.");
return( NULL );
}
int b_findstatenum = 1; // int nstate1 = 0, nstate2 = 0;
int b_returnprob = 1;
//-----------------------------------------------------
// copy data into new INT type array (hence quantization) and then reange them begin from 0 (i.e. state1)
int *vec1 = new int[len];
int *vec2 = new int[len];
if( !vec1 || !vec2 )
{
SG_UI_Msg_Add_Error("Fail to allocate memory.\n");
return( NULL );
}
int nrealstate1 = 0, nrealstate2 = 0;
Copy_Vector(img1, len, vec1, nrealstate1);
Copy_Vector(img2, len, vec2, nrealstate2);
//update the #state when necessary
nstate1 = (nstate1 < nrealstate1) ? nrealstate1 : nstate1;
//printf("First vector #state = %i\n",nrealstate1);
nstate2 = (nstate2 < nrealstate2) ? nrealstate2 : nstate2;
//printf("Second vector #state = %i\n",nrealstate2);
// if (nstate1!=maxstatenum || nstate2!=maxstatenum)
// printf("find nstate1=%d nstate2=%d\n", nstate1, nstate2);
//-----------------------------------------------------
// generate the joint-distribution table
double *hab = new double[nstate1 * nstate2];
double **hab2d = new double *[nstate2];
if( !hab || !hab2d )
{
SG_UI_Msg_Add_Error("Fail to allocate memory.");
return( NULL );
}
for(j=0; j<nstate2; j++)
{
hab2d[j] = hab + (long)j * nstate1;
}
for(i=0; i<nstate1; i++)
{
for(j=0; j<nstate2; j++)
{
hab2d[j][i] = 0;
}
}
for(i=0; i<len; i++)
{
// old method -- slow
// indx = (long)(vec2[i]) * nstate1 + vec1[i];
// hab[indx] += 1;
// new method -- fast
hab2d[vec2[i]][vec1[i]] += 1;
//printf("vec2[%d]=%d vec1[%d]=%d\n", i, vec2[i], i, vec1[i]);
}
//-----------------------------------------------------
// return the probabilities, otherwise return count numbers
if( b_returnprob )
{
for(i=0; i<nstate1; i++)
{
for(j=0; j<nstate2; j++)
{
hab2d[j][i] /= len;
}
}
}
//-----------------------------------------------------
// finish
DELETE_ARRAY(hab2d);
DELETE_ARRAY(vec1);
DELETE_ARRAY(vec2);
return hab;
}
