One can also think of applications where an entire plane (or cube) is needed. This is not supported, but can be implemented when needed.
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The user has to supply a function object derived from the abstract base
class LineCollapser or
TiledCollapser, resp..
The process function in these classes has to process
the chunk of data passed in. The nstepsDone function
in these classes can be used to monitor the progress.
The class is Doubly templated. Ths first template type is for the data type you are processing. The second type is for what type you want the results of the processing assigned to. For example, if you are computing sums of squares for statistical purposes, you might use higher precision (Float->Double) for this. No check is made that the template types are self-consistent.
Example
Collapse each line in the y-direction using my collapser function object.
MyLineCollapser collapser;
PagedArray<Float> latticeIn("lattice.file");
IPosition shape = latticeIn.shape();
shape(1) = 1;
ArrayLattice<Double> latticeOut(shape);
LatticeApply<Float,Double>::lineApply (latticeOut, latticeIn, collapser, 1);
Motivation
This class makes it possible that a user can apply functions to a lattice in an optimal way, without having to know all the details of iterating through a lattice.
Member Description
static void lineApply (MaskedLattice<U>& latticeOut, const MaskedLattice<T>& latticeIn, T<T,U>& collapser, uInt collapseAxis, LineCollapser* tellProgress = 0)
static void lineApply (MaskedLattice<U>& latticeOut, const MaskedLattice<T>& latticeIn, const T& region, LatticeRegion<T,U>& collapser, uInt collapseAxis, LineCollapser* tellProgress = 0)
This function iterates line by line through an input lattice and applies
a user supplied function object to each line along the specified axis.
The scalar result of the function object is written into the output
lattice at the location of the collapsed line. The output lattice must
be supplied with the correct shape (the shape of the supplied region).
The default region is the entire input lattice.
static void lineMultiApply (PtrBlock<MaskedLattice<U>*>& latticeOut, const MaskedLattice<T>& latticeIn, T<T,U>& collapser, uInt collapseAxis, LineCollapser* tellProgress = 0)
static void lineMultiApply (PtrBlock<MaskedLattice<U>*>& latticeOut, const MaskedLattice<T>& latticeIn, const T& region, LatticeRegion<T,U>& collapser, uInt collapseAxis, LineCollapser* tellProgress = 0)
This function iterates line by line through an input lattice and applies a user supplied function object to each line along the specified axis. The vector result of the function object is written into the output lattices at the location of the collapsed line (1 value per lattice). The output lattices must be supplied with the correct shape (the shape of the supplied region). The default region is the entire input lattice.
static void tiledApply (MaskedLattice<U>& latticeOut, const MaskedLattice<T>& latticeIn, TiledCollapser<T,U>& collapser, const IPosition& collapseAxes, Int newOutAxis = -1, iledCollapser* tellProgress = 0)
static void tiledApply (MaskedLattice<U>& latticeOut, const MaskedLattice<T>& latticeIn, const T& region, TiledCollapser<T,U>& collapser, const IPosition& collapseAxes, Int newOutAxis = -1, iledCollapser* tellProgress = 0)
This function iterates tile by tile through an input lattice and applies a user supplied function object to each chunk along the specified axes. A chunk can be a line, plane, etc. which is determined by the argument collapseAxes. E.g. IPosition(2,1,2) means planes along axes 1 and 2 (thus y,z planes). The result of the function object is written into the output lattice at the location of the collapsed chunk. The output lattice must be supplied with the correct shape (the shape of the supplied region plus the number of values resulting from the collapse). The default region is the entire input lattice.
static void tiledMultiApply (PtrBlock<MaskedLattice<U>*>& latticeOut, const MaskedLattice<T>& latticeIn, TiledCollapser<T,U>& collapser, const IPosition& collapseAxes, iledCollapser* tellProgress = 0)
static void tiledMultiApply (PtrBlock<MaskedLattice<U>*>& latticeOut, const MaskedLattice<T>& latticeIn, const T& region, TiledCollapser<T,U>& collapser, const IPosition& collapseAxes, iledCollapser* tellProgress = 0)
This function iterates tile by tile through an input lattice and applies a user supplied function object to each chunk along the specified axes. A chunk can be a line, plane, etc. which is determined by the argument collapseAxes. E.g. IPosition(2,1,2) means planes along axes 1 and 2 (thus y,z planes). The result of the function object is written into the output lattices at the location of the collapsed chunk. The output lattices must be supplied with the correct shape (the shape of the supplied region). The default region is the entire input lattice.
These functions are only declared, but not implemented yet. Thus they cannot be used yet.
static IPosition prepare (const IPosition& shapeIn, const IPosition& shapeOut, const IPosition& collapseAxes, Int newOutAxis)
Do some checks on the given arguments. It returns an IPosition with the same length as shapeOut. It contains a mapping of output to input axes. A value of -1 indicates that the axis is new (to contain the collapse result).Argument newOutAxis tells the output axis to store the results. -1 means that the function has to find it out itself; it takes the first axis with a length mismatching the corresponding input axis.