void saetrain(NN** saes, int numsaes, int numdata, const double** train_x, int numepochs, int batchsize)
{
int i, j;
double **train_data = (double**)train_x;
double **new_train_data = NULL;
for(i=0;i<numsaes; i++){
printf("Training AE %d / %d\n", i+1, numsaes);
if( i==0) {
nntrain(saes[i], numdata, (const double**)train_data, (const double**)train_data, numepochs, batchsize);
}else{
// generate data for next SAE
new_train_data = create2Darray( numdata, saes[i-1]->layer[0].units);
for(j=0; j<numdata; j++){
nnff(saes[i-1], j, (const double**)train_data) ;
memcpy( new_train_data[j], saes[i-1]->layer[0].a, saes[i-1]->layer[0].units);
}
nntrain(saes[i], numdata, (const double**)new_train_data, (const double**)new_train_data, numepochs, batchsize);
if( i > 1) free2Darray( train_data, numdata);
if( i== numsaes -1) free2Darray( new_train_data, numdata);
train_data = new_train_data;
}
}
}
int main(int arg, char* argv[])
{
int p = 2; // our basis order
double U[] = {0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 4.0, 5.0,5.0, 5.0}; // knot vector
int m = sizeof(U)/sizeof(double) - 1; // number of knot points
int n = m - p - 1; // number of basis functions
double u;
int c, span;
/*printf("Number of knot points: %d\n", m);
//
// Test our knot span index code
//
for(c = 0; c < m+1; ++c)
{
span = FindSpan(n, p, U[c], U);
printf("For Xi=%2.1f, the knot span index is i=%d\n\n",U[c], span);
}*/
//
// Now let's test our routines which calculate the basis functions and derivatives
//
int numNonZeroBsFns = p + 1;
/*
double *N = (double*)malloc(sizeof(double) * numNonZeroBsFns);
double **ders = init2DArray(n+1, p+1);
for(c = 0; c < numNonZeroBsFns; ++c) N[c] = 0.0;
double point[] = {0.0, 1.0, 2,0, 3.0, 4.0, 5.0}; // some sample points to evaluate at
int k = sizeof(point) / sizeof(double); // number of points (for our loop)
int j,d;
for(j = 0; j < k; ++j)
{
span = FindSpan(n, p, point[j], U); // get the span
BasisFuns( span, point[j], p, U, N); // get the non-zero basis functions
dersBasisFuns(span, point[j], p, n, U, ders); // get the derivatives ders[k][j]
// print out basis functions
printf("The non-zero basis functions in the range %2.2f and %2.2f and u=%2.2f are:\n",U[span], U[span+1], point[j]);
for(c = 0; c < numNonZeroBsFns; ++c) printf("\n %2.2f\n", N[c]);
// print out derivatives
for(d = 0; d < (n+1); d++)
{
printf("For k=%d, derivatives are: \n", d);
for(c = 0; c < numNonZeroBsFns; c++) printf("%2.2f\t", ders[d][c]);
printf("\n");
}
printf("\n\n");
}
free(N);
free2Darray(ders, n+1);
*/
double *dN = (double*)malloc(sizeof(double) * (n+1));
double **ders = init2DArray(n+1, p+1);
double xi, Nip;
int i=2;
printf("xi\tN\tdNdxi\n");
for(xi=0.0; xi <= 5.0; xi+=0.1)
{
span = FindSpan(n, p, xi, U);
Nip = OneBasisFun(p, m, U, i, xi);
dersOneBasisFuns(p, m, U, i, xi, n, dN);
}
xi = 2.1;
span = FindSpan(n, p, xi, U);
dersBasisFuns(span, xi, p, n, U, ders); // get the derivatives ders[k][j]
printf("\n\n%2.2f\t%2.20f\t%2.20f\t%2.20f\n",xi, ders[1][0], ders[1][1], ders[1][2]);
free(dN);
free2Darray(ders, n+1);
return 0;
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
/* Return the NURBS basis function to matlab
//
// We expect the function to be called as [Nip] = NURBSBasis(i, p, xi, knot, weights)
//
// p = order of basis (0,1,2 etc)
// knot = knot vector
// i = basis function we want (1,2,3 ie. Hughes' notation)
// xi = the coordinate we wish to evaluate at
// weights = the weightings for the NURNS function (length(weights) = m - p -1) */
if(nrhs != 5) mexErrMsgTxt("You fool! You haven't passed in 5 arguments to the function."
"We expect it to be in the form [Nip] = NURBSBasis(i, p, xi, knot, weights)\n");
int c, k, p, m, i, numKnot, numWeights;
double *p_in, *m_in, *i_in;
double *knot, *xi, *weight;
double tol=100*DBL_EPSILON;
for(c = 0; c < nrhs; c++)
{
switch(c)
{
case 0:
i_in = mxGetPr(prhs[c]);
i = (int)*i_in -1;
/*mexPrintf("\n\ni=%d\n", i);*/
case 1:
p_in = mxGetPr(prhs[c]);
p = (int)*p_in;
/*mexPrintf("\n\np=%d\n", p);*/
case 2:
xi = mxGetPr(prhs[c]);
/*mexPrintf("\nxi=%2.20f\n", *xi); */
case 3:
knot = mxGetPr(prhs[c]);
numKnot = mxGetN(prhs[c]);
m = numKnot - 1;
/*mexPrintf("\nWe have a knot vector with %d components\n", numKnot);
for(k = 0; k < numKnot; k++) mexPrintf("%2.2f\t", *(knot+k));
mexPrintf("\n");*/
case 4:
weight = mxGetPr(prhs[c]);
numWeights = mxGetM(prhs[c]);
}
}
if(fabs(*xi-knot[numKnot-1]) < tol)
*xi = knot[numKnot-1] - tol;
/* and call the basis function routine*/
double Rip, Nip, dRip_dxi;
double w_interp, dw_interp_dxi ;
int n = m - p -1;
double *N = (double *)malloc(sizeof(double)*(p+1));
double *dN = (double *)malloc(sizeof(double)*(p+1));
double **ders = init2DArray(p+1, p+1);
int span = FindSpan(n, p, *xi, knot);
BasisFuns(span, *xi, p, knot, N);
dersBasisFuns(span, *xi, p, p, knot, ders);
w_interp = 0.0;
dw_interp_dxi = 0.0;
for(c = 0; c <= p; c++)
{
w_interp += N[c] * weight[span-p+c];
dw_interp_dxi += ders[1][c] * weight[span-p+c];
}
dersOneBasisFuns(p, m, knot, i, *xi, p, dN);
Nip = OneBasisFun(p, m, knot, i, *xi);
Rip = Nip * weight[i] / w_interp;
dRip_dxi = weight[i] * ( w_interp * dN[1] - dw_interp_dxi * Nip ) / (w_interp * w_interp);
free2Darray(ders, (p+1));
free(N);
free(dN);
plhs[0] = mxCreateDoubleScalar(Rip);
plhs[1] = mxCreateDoubleScalar(dRip_dxi);
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
/* Return the NURBS basis function to matlab
//
// We expect the function to be called as [interp interp_deriv] = NURBSinterpolation(xi, p, knot, points, weights)
//
// xi = point where we want to interpolate
// knot = knot vector
// vector of points in format [pt1 pt2 pt3 pt4 .... ptn] */
if(nrhs != 5) mexErrMsgTxt("You fool! You haven't passed in 3 arguments to the function."
"We expect it to be in the form [interp interp_deriv] = NURBSinterpolation(xi, knot, points)\n");
/* First get the inputs */
double *xi = mxGetPr(prhs[0]);
double *p_in = (mxGetPr(prhs[1]));
int p = (int) *p_in;
double *knot = mxGetPr(prhs[2]);
int numKnot = mxGetN(prhs[2]);
int m = numKnot - 1;
int n = m - p -1;
double *points = mxGetPr(prhs[3]);
int numPoints = mxGetN(prhs[3]);
double *weight = mxGetPr(prhs[4]);
int numWeights = mxGetN(prhs[4]);
double tol=100*DBL_EPSILON;
if(fabs(*xi-knot[numKnot-1]) < tol)
*xi = knot[numKnot-1] - tol;
/* and evaluate the non-zero basis functions*/
double *N = (double *)malloc(sizeof(double)*(p+1));
double *NURBS = (double *)malloc(sizeof(double)*(p+1));
double *NURBS_deriv = (double *)malloc(sizeof(double)*(p+1));
double **ders = init2DArray(n+1, p+1);
int span = FindSpan(n, p, *xi, knot);
BasisFuns(span, *xi, p, knot, N);
dersBasisFuns(span, *xi, p, n, knot, ders);
/* and create NURBS approximation */
int k, c;
for(k = 0; k <=p; k++)
{
double w_interp = 0.0, dw_interp_dxi= 0.0;
for(c = 0; c <= p; c++)
{
w_interp += N[c] * weight[span-p+c];
dw_interp_dxi += ders[1][c] * weight[span-p+c];
}
NURBS[k] = N[k] * weight[span-p+k] / w_interp;
NURBS_deriv[k] = weight[span-p+k] * ( w_interp * ders[1][k] - dw_interp_dxi * N[k] ) / (w_interp * w_interp);
}
double interp = 0.0;
double interp_deriv = 0.0;
for(c = 0; c <= p; c++)
{
interp += NURBS[c] * points[span-p+c];
interp_deriv += NURBS_deriv[c] * points[span-p+c];
}
free(N);
free(NURBS);
free(NURBS_deriv);
free2Darray(ders, (n+1));
plhs[0] = mxCreateDoubleScalar(interp); plhs[1] = mxCreateDoubleScalar(interp_deriv);
}
