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#include <AOFlagger/strategy/algorithms/polfitmethod.h>
PolFitMethod::PolFitMethod() : _background(0), _previousCoefficients(0) {}
PolFitMethod::~PolFitMethod() {
if (_background != 0) delete _background;
}
void PolFitMethod::Initialize(const TimeFrequencyData& input) {
_original = input.GetSingleImage();
_background2D =
Image2D::CreateEmptyImagePtr(_original->Width(), _original->Height());
if (_background != 0) delete _background;
_background = new TimeFrequencyData(input.PhaseRepresentation(),
input.Polarisation(), _background2D);
_mask = input.GetSingleMask();
if (_hSquareSize * 2 > _original->Width())
_hSquareSize = _original->Width() / 2;
if (_vSquareSize * 2 > _original->Height())
_vSquareSize = _original->Height() / 2;
}
unsigned PolFitMethod::TaskCount() { return _original->Height(); }
void PolFitMethod::PerformFit(unsigned taskNumber) {
if (_mask == 0) throw BadUsageException("Mask has not been set!");
unsigned y = taskNumber;
for (unsigned x = 0; x < _original->Width(); ++x)
_background2D->SetValue(x, y, CalculateBackgroundValue(x, y));
}
long double PolFitMethod::CalculateBackgroundValue(unsigned x, unsigned y) {
ThreadLocal local;
local.image = this;
local.currentX = x;
local.currentY = y;
if (local.currentY >= _vSquareSize)
local.startY = local.currentY - _vSquareSize;
else
local.startY = 0;
local.endY = local.currentY + _vSquareSize;
if (local.endY >= _original->Height()) local.endY = _original->Height() - 1;
if (local.currentX >= _hSquareSize)
local.startX = local.currentX - _hSquareSize;
else
local.startX = 0;
local.endX = local.currentX + _hSquareSize;
if (local.endX >= _original->Width()) local.endX = _original->Width() - 1;
local.emptyWindows = 0;
switch (_method) {
case None:
return 0.0;
case LeastSquare:
case LeastAbs:
case FastGaussianWeightedAverage:
return FitBackground(x, y, local);
default:
throw ConfigurationException(
"The PolFitMethod was not initialized before a fit was executed.");
}
}
int PolFitMethod::SquareError(const gsl_vector* coefs, void* data,
gsl_vector* f) {
// f(x,y) = ( a * x^2 + b * xy + c * y^2 + d x + e y + l - image[x,y] )^2
ThreadLocal& local = *(ThreadLocal*)data;
double a = gsl_vector_get(coefs, 0);
double b = gsl_vector_get(coefs, 1);
double c = gsl_vector_get(coefs, 2);
double d = gsl_vector_get(coefs, 3);
double e = gsl_vector_get(coefs, 4);
double l = gsl_vector_get(coefs, 5);
unsigned index = 0;
for (unsigned y = local.startY; y <= local.endY; ++y) {
double yf = y;
for (unsigned x = local.startX; x <= local.endX; ++x) {
if (!local.image->_mask->Value(x, y)) {
double xf = x;
double g_xy = a * xf * xf + b * xf * yf + c * yf * yf + d * xf +
e * yf + l - local.image->_original->Value(x, y);
gsl_vector_set(f, index, (g_xy * g_xy));
} else {
gsl_vector_set(f, index, 0.0);
}
index++;
}
}
return GSL_SUCCESS;
}
int PolFitMethod::SquareErrorDiff(const gsl_vector* coefs, void* data,
gsl_matrix* J) {
ThreadLocal& local = *(ThreadLocal*)data;
double a = gsl_vector_get(coefs, 0);
double b = gsl_vector_get(coefs, 1);
double c = gsl_vector_get(coefs, 2);
double d = gsl_vector_get(coefs, 3);
double e = gsl_vector_get(coefs, 4);
double f = gsl_vector_get(coefs, 5);
unsigned index = 0;
for (unsigned y = local.startY; y <= local.endY; ++y) {
double yf = y;
for (unsigned x = local.startX; x <= local.endX; ++x) {
if (!local.image->_mask->Value(x, y)) {
// f(x,y) = ( a * x^2 + b * xy + c * y^2 + d x + e y + f - image[x,y]
// )^2 f(x,y) = g^2(x,y) df(x,y)/dz = 2 * g(x,y) * dg(x,y)/dz We now
// need to calculate df(x,y)/da, df(x,y)/db, ..... for each x and y
double xf = x;
double g_xy = 2.0 * (a * xf * xf + b * xf * yf + c * yf * yf + d * xf +
e * yf + f - local.image->_original->Value(x, y));
gsl_matrix_set(J, index, 0, g_xy * xf * xf); // df/da
gsl_matrix_set(J, index, 1, g_xy * xf * yf); // df/db
gsl_matrix_set(J, index, 2, g_xy * yf * yf); // df/dc
gsl_matrix_set(J, index, 3, g_xy * xf); // df/dd
gsl_matrix_set(J, index, 4, g_xy * yf); // df/de
gsl_matrix_set(J, index, 5, g_xy); // df/df
} else {
for (unsigned ci = 0; ci < 6; ++ci) gsl_matrix_set(J, index, ci, 0.0);
}
index++;
}
}
return GSL_SUCCESS;
}
int PolFitMethod::LinError(const gsl_vector* coefs, void* data, gsl_vector* f) {
// f(x,y) = | a * x^2 + b * xy + c * y^2 + d x + e y + l - image[x,y] |
ThreadLocal& local = *(ThreadLocal*)data;
double a = gsl_vector_get(coefs, 0);
double b = gsl_vector_get(coefs, 1);
double c = gsl_vector_get(coefs, 2);
double d = gsl_vector_get(coefs, 3);
double e = gsl_vector_get(coefs, 4);
double l = gsl_vector_get(coefs, 5);
unsigned index = 0;
for (unsigned y = local.startY; y <= local.endY; ++y) {
double yf = y;
for (unsigned x = local.startX; x <= local.endX; ++x) {
if (!local.image->_mask->Value(x, y)) {
double xf = x;
double g_xy = a * xf * xf + b * xf * yf + c * yf * yf + d * xf +
e * yf + l - local.image->_original->Value(x, y);
gsl_vector_set(f, index, fabs(g_xy));
} else {
gsl_vector_set(f, index, 0.0);
}
index++;
}
}
return GSL_SUCCESS;
}
int PolFitMethod::LinErrorDiff(const gsl_vector* coefs, void* data,
gsl_matrix* J) {
ThreadLocal& local = *(ThreadLocal*)data;
double a = gsl_vector_get(coefs, 0);
double b = gsl_vector_get(coefs, 1);
double c = gsl_vector_get(coefs, 2);
double d = gsl_vector_get(coefs, 3);
double e = gsl_vector_get(coefs, 4);
double f = gsl_vector_get(coefs, 5);
unsigned index = 0;
for (unsigned y = local.startY; y <= local.endY; ++y) {
double yf = y;
for (unsigned x = local.startX; x <= local.endX; ++x) {
if (!local.image->_mask->Value(x, y)) {
// f(x,y) = | a * x^2 + b * xy + c * y^2 + d x + e y + f - image[x,y]
// | f(x,y) = | g(x,y) | df(x,y)/dz = dg(x,y)/dz * g(x,y) / | g(x,y) |
// We now need to calculate df(x,y)/da, df(x,y)/db, ..... for each x and
// y
double xf = x;
double g_xy = a * xf * xf + b * xf * yf + c * yf * yf + d * xf +
e * yf + f - local.image->_original->Value(x, y);
double h_xy = g_xy / fabs(g_xy);
gsl_matrix_set(J, index, 0, h_xy * xf * xf); // df/da
gsl_matrix_set(J, index, 1, h_xy * xf * yf); // df/db
gsl_matrix_set(J, index, 2, h_xy * yf * yf); // df/dc
gsl_matrix_set(J, index, 3, h_xy * xf); // df/dd
gsl_matrix_set(J, index, 4, h_xy * yf); // df/de
gsl_matrix_set(J, index, 5, h_xy); // df/df
} else {
for (unsigned ci = 0; ci < 6; ++ci) gsl_matrix_set(J, index, ci, 0.0);
}
index++;
}
}
return GSL_SUCCESS;
}
long double PolFitMethod::FitBackground(unsigned x, unsigned y,
ThreadLocal& local) {
std::vector<long double> coefficients(6);
boost::mutex::scoped_lock lock(_mutex);
if (_previousCoefficients) {
for (unsigned i = 0; i < 6; ++i) coefficients[i] = _previousCoefficients[i];
} else {
for (unsigned i = 0; i < 6; ++i) coefficients[i] = 1e-4 * (i * i * i);
}
lock.unlock();
// Chose to use the Levenberg-Marquardt solver with scaling
const gsl_multifit_fdfsolver_type* T = gsl_multifit_fdfsolver_lmsder;
// Construct solver
unsigned functionCount =
(local.endY - local.startY + 1) * (local.endX - local.startX + 1);
unsigned coefficientCount = 6;
gsl_multifit_fdfsolver* solver =
gsl_multifit_fdfsolver_alloc(T, functionCount, coefficientCount);
if (solver == 0) throw BadUsageException("No solver.");
// Initialize function information structure
gsl_multifit_function_fdf functionInfo;
switch (_method) {
case LeastSquare:
default:
functionInfo.f = &SquareError;
functionInfo.df = &SquareErrorDiff;
functionInfo.fdf = &SquareErrorComb;
break;
case LeastAbs:
functionInfo.f = &LinError;
functionInfo.df = &LinErrorDiff;
functionInfo.fdf = &LinErrorComb;
break;
}
functionInfo.n = functionCount;
functionInfo.p = coefficientCount;
functionInfo.params = &local;
// Initialize initial value of parameters
// gsl_vector vec;
double vec_init[coefficientCount];
for (unsigned i = 0; i < coefficientCount; ++i) vec_init[i] = coefficients[i];
gsl_vector_view vec_view = gsl_vector_view_array(vec_init, coefficientCount);
int status =
gsl_multifit_fdfsolver_set(solver, &functionInfo, &vec_view.vector);
if (status && status != GSL_CONTINUE) {
std::cout << "Error: status = " << gsl_strerror(status) << std::endl;
}
// Start iterating
int iter = 0;
do {
iter++;
status = gsl_multifit_fdfsolver_iterate(solver);
// PrintState(iter, solver);
if (status && status != GSL_CONTINUE) {
// std::cout << "Error: status = " << gsl_strerror (status) << std::endl;
break;
}
status =
gsl_multifit_test_delta(solver->dx, solver->x, _precision, _precision);
} while (status == GSL_CONTINUE && iter < 250);
// Save coefficients
for (unsigned i = 0; i < coefficientCount; ++i)
coefficients[i] = gsl_vector_get(solver->x, i);
lock.lock();
if (_previousCoefficients == 0) _previousCoefficients = new long double[6];
for (unsigned i = 0; i < coefficientCount; ++i)
_previousCoefficients[i] = coefficients[i];
lock.unlock();
// Clean up
gsl_multifit_fdfsolver_free(solver);
long double evaluation = Evaluate(x, y, coefficients);
return evaluation;
}
long double PolFitMethod::Evaluate(unsigned x, unsigned y,
long double* coefficients) {
// f(x,y) = a * x^2 + b * xy + c * y^2 + d x + e y + f
double xf = x, yf = y;
return coefficients[0] * xf * xf + coefficients[1] * xf * yf +
coefficients[2] * yf * yf + coefficients[3] * xf +
coefficients[4] * yf + coefficients[5];
}
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