/** Calculate the derivatives for a set of points on the spline
*
* @param out :: The array to store the derivatives in
* @param xValues :: The array of x values we wish to know the derivatives of
* @param nData :: The size of the arrays
* @param order :: The order of the derivatives o calculate
*/
void CubicSpline::derivative1D(double* out, const double* xValues, size_t nData, const size_t order) const
{
int n = getAttribute("n").asInt();
boost::scoped_array<double> x(new double[n]);
boost::scoped_array<double> y(new double[n]);
//setup the reference points and calculate
if(m_recalculateSpline) setupInput(x,y,n);
calculateDerivative(out,xValues,nData,order);
}
void updateWeights(Neuron* neuron) {
double derivative = calculateDerivative(neuron);
int i;
for(i = 0 ; i < neuron->inputCount ; i++) {
//printf("Updating weights with input val %f\n",neuron->inputs[i]);
//printf("Updating weights with errorSignal val %f\n",neuron->errorSignal);
neuron->weights[i] = neuron->weights[i] + (0.1 * neuron->errorSignal * derivative * neuron->inputs[i]);
//printf("New weight value for %d: %f\n",i,neuron->weights[i]);
}
}
ViEigenBaseVector* ViFourierInterpolator::estimateModelSplines(const int °ree, const int &derivative, const qreal *leftSamples, const int &leftSize, const qreal *rightSamples, const int &rightSize, const int &outputSize, const qreal &scaling)
{
static int i, j, extraEquations, columnOffset1, columnOffset2, rowOffset1, rowOffset2, rightStart, splineCount, leftSplineCount, rightSplineCount, singleCoefficientCount, coefficientCount, derivativeCount, equationCount, size;
static qreal x1, x2, value1, value2;
size = leftSize + rightSize;
if(size <= 1) return NULL;
rightStart = leftSize + outputSize;
splineCount = size - 1;
leftSplineCount = leftSize - 1;
rightSplineCount = rightSize - 1;
singleCoefficientCount = (degree * 2) + 1;
coefficientCount = splineCount * singleCoefficientCount;
derivativeCount = splineCount - 1;
extraEquations = 0;
equationCount = 0;
equationCount += splineCount * 2; // Spline polynomials. Times 2 since we use the spline with 2 points
equationCount += derivativeCount * derivative; // Intermediate derivatives should be equal;
while(equationCount < coefficientCount) // Add first spline == 0
{
++equationCount;
++extraEquations;
}
ViEigenBaseMatrix *matrix = mEigen->createMatrix(equationCount, coefficientCount);
ViEigenBaseVector *vector = mEigen->createVector(equationCount);
// Add left spline polynomials
for(i = 0; i < leftSplineCount; ++i)
{
rowOffset1 = i * 2;
rowOffset2 = rowOffset1 + 1;
columnOffset1 = singleCoefficientCount * i;
columnOffset2 = columnOffset1 + degree;
vector->set(rowOffset1, leftSamples[i]);
vector->set(rowOffset2, leftSamples[i + 1]);
x1 = i * scaling;
x2 = (i + 1) * scaling;
matrix->set(rowOffset1, columnOffset1, 0.5);
matrix->set(rowOffset2, columnOffset1, 0.5);
for(j = 1; j <= degree; ++j)
{
value1 = x1 * j;
value2 = x2 * j;
matrix->setCos(rowOffset1, j + columnOffset1, value1);
matrix->setCos(rowOffset2, j + columnOffset1, value2);
matrix->setSin(rowOffset1, j + columnOffset2, value1);
matrix->setSin(rowOffset2, j + columnOffset2, value2);
}
}
// Add the spline polynomial that runs over the output gap, aka between the last left and first right sample
rowOffset1 = leftSplineCount * 2;
rowOffset2 = rowOffset1 + 1;
columnOffset1 = singleCoefficientCount * leftSplineCount;
columnOffset2 = columnOffset1 + degree;
vector->set(rowOffset1, leftSamples[leftSize - 1]);
vector->set(rowOffset2, rightSamples[0]);
x1 = (leftSize - 1) * scaling;
x2 = (leftSize + outputSize) * scaling;
matrix->set(rowOffset1, columnOffset1, 0.5);
matrix->set(rowOffset2, columnOffset1, 0.5);
for(j = 1; j <= degree; ++j)
{
value1 = x1 * j;
value2 = x2 * j;
matrix->setCos(rowOffset1, j + columnOffset1, value1);
matrix->setCos(rowOffset2, j + columnOffset1, value2);
matrix->setSin(rowOffset1, j + columnOffset2, value1);
matrix->setSin(rowOffset2, j + columnOffset2, value2);
}
// Add right spline polynomials
for(i = 0; i < rightSplineCount; ++i)
{
rowOffset1 = (leftSplineCount + i + 1) * 2;
rowOffset2 = rowOffset1 + 1;
columnOffset1 = singleCoefficientCount * (i + leftSplineCount + 1);
columnOffset2 = columnOffset1 + degree;
vector->set(rowOffset1, rightSamples[i]);
vector->set(rowOffset2, rightSamples[i + 1]);
x1 = (rightStart + i) * scaling;
x2 = (rightStart + i + 1) * scaling;
matrix->set(rowOffset1, columnOffset1, 0.5);
matrix->set(rowOffset2, columnOffset1, 0.5);
for(j = 1; j <= degree; ++j)
{
value1 = x1 * j;
value2 = x2 * j;
matrix->setCos(rowOffset1, j + columnOffset1, value1);
matrix->setCos(rowOffset2, j + columnOffset1, value2);
matrix->setSin(rowOffset1, j + columnOffset2, value1);
matrix->setSin(rowOffset2, j + columnOffset2, value2);
}
}
// Add the deratives between neighbouring left splines
for(i = 1; i <= derivative; ++i)
{
rowOffset1 = (splineCount * 2) + ((i - 1) * leftSplineCount);
for(j = 0; j < leftSplineCount; ++j)
{
rowOffset2 = rowOffset1 + j;
columnOffset1 = j * singleCoefficientCount;
x1 = (j + 1) * scaling;
calculateDerivative(degree, x1, matrix, rowOffset2, i, columnOffset1, 1);
calculateDerivative(degree, x1, matrix, rowOffset2, i, columnOffset1 + singleCoefficientCount, -1); // -1: take the derivative on the right-hand side to the left of the equation
}
}
// Add the deratives between neighbouring right splines
for(i = 1; i <= derivative; ++i)
{
rowOffset1 = (splineCount * 2) + ((i - 1) * rightSplineCount) + (leftSplineCount * derivative);
for(j = 0; j < rightSplineCount; ++j)
{
rowOffset2 = rowOffset1 + j;
columnOffset1 = (j + leftSplineCount) * singleCoefficientCount;
x1 = (rightStart + j) * scaling;
calculateDerivative(degree, x1, matrix, rowOffset2, i, columnOffset1, 1);
calculateDerivative(degree, x1, matrix, rowOffset2, i, columnOffset1 + singleCoefficientCount, -1); // -1: take the derivative on the right-hand side to the left of the equation
}
}
// Set the derivitives for the first spline at point 0 to 0
if(extraEquations > 0)
{
for(i = 1; i <= extraEquations; ++i) matrix->set(equationCount - i, 0, 1);
}
ViEigenBaseVector *coefficients = mEigen->estimate(matrix, vector);
mEigen->clear(matrix);
mEigen->clear(vector);
return coefficients;
}
ViEigenBaseVector* ViFourierInterpolator::estimateModelOsculating(const int °ree, const int &derivative, const qreal *leftSamples, const int &leftSize, const qreal *rightSamples, const int &rightSize, const int &outputSize, const qreal &scaling)
{
static int i, j, offset, start, end, derivativeCount, totalDerivatives, totalSize, size;
static qreal x, value;
size = leftSize + rightSize;
derivativeCount = size - 4; // Average, we don't have derivatives for the first and last point for both sides
totalDerivatives = derivativeCount * derivative;
totalSize = size + totalDerivatives;
ViEigenBaseMatrix *matrix = mEigen->createMatrix(totalSize, (2 * degree) + 1);
ViEigenBaseVector *vector = mEigen->createVector(totalSize);
for(i = 0; i < leftSize; ++i)
{
vector->set(i, leftSamples[i]);
x = i * scaling;
matrix->set(i, 0, 0.5);
for(j = 1; j <= degree; ++j)
{
value = x * j;
matrix->setCos(i, j, value);
matrix->setSin(i, j + degree, value);
}
}
for(i = 0; i < rightSize; ++i)
{
offset = leftSize + i;
vector->set(offset, rightSamples[i]);
x = (offset + outputSize) * scaling;
matrix->set(offset, 0, 0.5);
for(j = 1; j <= degree; ++j)
{
value = x * j;
matrix->setCos(offset, j, value);
matrix->setSin(offset, j + degree, value);
}
}
// Determine for how many samples we cannot calculate a derivitate, and skip those equations.
// Der1 and der2 must skip 1 sample at the start and 1 at the end, der3 and der4 skip 2, etc
start = ceil(derivative / 2.0);
qreal derivativesLeft[leftSize];
qreal derivativesRight[rightSize];
end = leftSize - start;
for(i = 1; i <= derivative; ++i)
{
ViDifferentiater::derivative(i, leftSamples, leftSize, derivativesLeft);
for(j = start; j < end; ++j)
{
offset = size + (derivativeCount * (i - 1)) + (j - 1);
vector->set(offset, derivativesLeft[j]);
calculateDerivative(degree, j * scaling, matrix, offset, i);
}
}
end = rightSize - start;
for(i = 1; i <= derivative; ++i)
{
ViDifferentiater::derivative(i, rightSamples, rightSize, derivativesRight);
for(j = start; j < end; ++j)
{
offset = (leftSize - 2) + size + (derivativeCount * (i - 1)) + (j - 1);
vector->set(offset, derivativesRight[j]);
calculateDerivative(degree, j * scaling, matrix, offset, i);
}
}
ViEigenBaseVector *coefficients = mEigen->estimate(matrix, vector);
mEigen->clear(matrix);
mEigen->clear(vector);
return coefficients;
}
