InterpolationTables/src/ArrayNDScanner.cc

0001 #include "JetMETCorrections/InterpolationTables/interface/NpstatException.h"
0002 #include <cassert>
0003
0004 #include "JetMETCorrections/InterpolationTables/interface/ArrayNDScanner.h"
0005
0006 namespace npstat {
0007   void ArrayNDScanner::initialize(const unsigned* shape, const unsigned lenShape) {
0008     // Check argument validity
0009     if (lenShape == 0U || lenShape >= CHAR_BIT * sizeof(unsigned long))
0010       throw npstat::NpstatInvalidArgument("In npstat::ArrayNDScanner::initialize: invalid scan shape");
0011     assert(shape);
0012     for (unsigned j = 0; j < lenShape; ++j)
0013       if (!shape[j])
0014         throw npstat::NpstatInvalidArgument(
0015             "In npstat::ArrayNDScanner::initialize: "
0016             "number of scans must be positive in each dimension");
0017
0018     // Initialize the scanner data
0019     state_ = 0UL;
0020     dim_ = lenShape;
0021     strides_[dim_ - 1] = 1UL;
0022     for (unsigned j = dim_ - 1; j > 0; --j)
0023       strides_[j - 1] = strides_[j] * shape[j];
0024     maxState_ = strides_[0] * shape[0];
0025   }
0026
0027   void ArrayNDScanner::getIndex(unsigned* ix, const unsigned indexBufferLen) const {
0028     if (indexBufferLen < dim_)
0029       throw npstat::NpstatInvalidArgument(
0030           "In npstat::ArrayNDScanner::getIndex: "
0031           "insufficient length of the output buffer");
0032     if (state_ >= maxState_)
0033       throw npstat::NpstatRuntimeError("In npstat::ArrayNDScanner::getIndex: invalid scanner state");
0034     assert(ix);
0035
0036     unsigned long l = state_;
0037     for (unsigned i = 0; i < dim_; ++i) {
0038       unsigned long idx = l / strides_[i];
0039       ix[i] = static_cast<unsigned>(idx);
0040       l -= (idx * strides_[i]);
0041     }
0042   }
0043 }  // namespace npstat