/** Constructor helper method
* @param min :: nd-sized vector of the minimum edge of the box in each
* dimension
* @param max :: nd-sized vector of the maximum edge of the box
* */
void MDBoxImplicitFunction::construct(const Mantid::Kernel::VMD &min,
const Mantid::Kernel::VMD &max) {
size_t nd = min.size();
if (max.size() != nd)
throw std::invalid_argument(
"MDBoxImplicitFunction::ctor(): Min and max vector sizes must match!");
if (nd == 0 || nd > 100)
throw std::invalid_argument(
"MDBoxImplicitFunction::ctor(): Invalid number of dimensions!");
double volume = 1;
for (size_t d = 0; d < nd; d++) {
volume *= (max[d] - min[d]);
// Make two parallel planes per dimension
// Normal on the min side, so it faces towards +X
std::vector<coord_t> normal_min(nd, 0);
normal_min[d] = +1.0;
// Origin just needs to have its X set to the value. Other coords are
// irrelevant
std::vector<coord_t> origin_min(nd, 0);
origin_min[d] = static_cast<coord_t>(min[d]);
// Build the plane
MDPlane p_min(normal_min, origin_min);
this->addPlane(p_min);
// Normal on the max side, so it faces towards -X
std::vector<coord_t> normal_max(nd, 0);
normal_max[d] = -1.0;
// Origin just needs to have its X set to the value. Other coords are
// irrelevant
std::vector<coord_t> origin_max(nd, 0);
origin_max[d] = static_cast<coord_t>(max[d]);
// Build the plane
MDPlane p_max(normal_max, origin_max);
this->addPlane(p_max);
}
m_volume = volume;
}
/** Build a coordinate transformation based on an origin and orthogonal basis vectors.
* This can reduce the number of dimensions. For example:
*
* - The input position is X=(x,y,z)
* - The origin is X0=(x0,y0,z0)
* - The basis vectors are U and V (reducing from 3 to 2D)
* - The output position u = (X-X0).U = X.U - X0.U = x*Ux + y*Uy + z*Uz + (X0.U)
* - The output position v = (X-X0).V = X.V - X0.V = x*Vx + y*Vy + z*Vz + (X0.V)
*
* And this allows us to create the affine matrix:
*
* | Ux Uy Uz X0.U | | x | | u |
* | Vx Vy Vz X0.V | | y | = | v |
* | 0 0 0 1 | | z | | 1 |
* | 1 |
*
* @param origin :: origin (in the inDimension), which corresponds to (0,0,...) in outD
* @param axes :: a list of basis vectors. There must be outD vectors (one for each output dimension)
* and each vector must be of length inD (all coordinates in the input dimension).
* The vectors must be properly orthogonal: not coplanar or collinear. This is not checked!
* @param scaling :: a vector of size outD of the scaling to perform in each of the
* OUTPUT dimensions.
* @throw if inconsistent vector sizes are received, or zero-length
*/
void CoordTransformAffine::buildOrthogonal(const Mantid::Kernel::VMD & origin, const std::vector< Mantid::Kernel::VMD> & axes,
const Mantid::Kernel::VMD & scaling)
{
if (origin.size() != inD)
throw std::runtime_error("CoordTransformAffine::buildOrthogonal(): the origin must be in the dimensions of the input workspace (length inD).");
if (axes.size() != outD)
throw std::runtime_error("CoordTransformAffine::buildOrthogonal(): you must give as many basis vectors as there are dimensions in the output workspace.");
if (scaling.size() != outD)
throw std::runtime_error("CoordTransformAffine::buildOrthogonal(): the size of the scaling vector must be the same as the number of dimensions in the output workspace.");
// Start with identity
affineMatrix.identityMatrix();
for (size_t i=0; i<axes.size(); i++)
{
if (axes[i].length() == 0.0)
throw std::runtime_error("CoordTransformAffine::buildOrthogonal(): one of the basis vector was of zero length.");
if (axes[i].size() != inD)
throw std::runtime_error("CoordTransformAffine::buildOrthogonal(): one of the basis vectors had the wrong number of dimensions (must be inD).");
// Normalize each axis to unity
VMD basis = axes[i];
basis.normalize();
// The row of the affine matrix = the unit vector
for (size_t j=0; j<basis.size(); j++)
affineMatrix[i][j] = basis[j] * scaling[i];
// Now account for the translation
coord_t transl = 0;
for (size_t j=0; j<basis.size(); j++)
transl += origin[j] * basis[j]; // dot product of origin * basis aka ( X0 . U )
// The last column of the matrix = the translation movement
affineMatrix[i][inD] = -transl * scaling[i];
}
// Copy into the raw matrix (for speed)
copyRawMatrix();
}