void ExportFileFunctions::loadYRadiusValuesForCurveInterpolatedSmooth (const DocumentModelCoords &modelCoords,
const MainWindowModel &modelMainWindow,
const Points &points,
const ExportValuesXOrY &xThetaValues,
const Transformation &transformation,
QVector<QString*> &yRadiusValues) const
{
LOG4CPP_INFO_S ((*mainCat)) << "ExportFileFunctions::loadYRadiusValuesForCurveInterpolatedSmooth";
// Convert screen coordinates to graph coordinates, in vectors suitable for spline fitting
vector<double> t;
vector<SplinePair> xy;
ExportOrdinalsSmooth ordinalsSmooth;
ordinalsSmooth.loadSplinePairsWithTransformation (points,
transformation,
t,
xy);
// Formatting
FormatCoordsUnits format;
QString dummyXThetaOut;
if (points.count() == 0) {
// Since there are no values, leave the field empty
for (int row = 0; row < xThetaValues.count(); row++) {
*(yRadiusValues [row]) = "";
}
} else if (points.count() == 1 ||
points.count() == 2) {
// Apply the single value everywhere (N=1) or do linear interpolation (N=2)
for (int row = 0; row < xThetaValues.count(); row++) {
double xTheta = xThetaValues.at (row);
double yRadius;
if (points.count() == 1) {
yRadius = xy.at (0).y ();
} else {
double x0 = xy.at (0).x ();
double x1 = xy.at (1).x ();
double y0 = xy.at (0).y ();
double y1 = xy.at (1).y ();
if (x0 == x1) {
// Cannot do linear interpolation using two points at the same x value
yRadius = xy.at (0).y ();
} else {
double s = (xTheta - x0) / (x1 - x0);
yRadius = (1.0 - s) * y0 + s * y1;
}
}
format.unformattedToFormatted (xTheta,
yRadius,
modelCoords,
modelMainWindow,
dummyXThetaOut,
*(yRadiusValues [row]),
transformation);
}
} else {
// Iteration accuracy versus number of iterations 8->256, 10->1024, 12->4096. Single pixel accuracy out of
// typical image size of 1024x1024 means around 10 iterations gives decent accuracy for numbers much bigger
// than 1. A value of 12 gave some differences in the least significant figures of numbers like 10^-3 in
// the regression tests. Toggling between 30 and 32 made no difference in the regression tests.
const int MAX_ITERATIONS = 32;
// Spline class requires at least one point
if (xy.size() > 0) {
// Fit a spline
Spline spline (t,
xy);
// Get value at desired points
for (int row = 0; row < xThetaValues.count(); row++) {
double xTheta = xThetaValues.at (row);
SplinePair splinePairFound = spline.findSplinePairForFunctionX (xTheta,
MAX_ITERATIONS);
double yRadius = splinePairFound.y ();
// Save y/radius value for this row into yRadiusValues, after appropriate formatting
QString dummyXThetaOut;
format.unformattedToFormatted (xTheta,
yRadius,
modelCoords,
modelMainWindow,
dummyXThetaOut,
*(yRadiusValues [row]),
transformation);
}
}
}
}
