sequence_context.cpp
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#include "sequence_context.h"
#include "sequence_store.h"
#include <cmath>
using namespace Poincare;
namespace Sequence {
template<typename T>
TemplatedSequenceContext<T>::TemplatedSequenceContext() :
m_rank(-1),
m_values{{NAN, NAN, NAN},{NAN, NAN, NAN}}
{
}
template<typename T>
T TemplatedSequenceContext<T>::valueOfSequenceAtPreviousRank(int sequenceIndex, int rank) const {
return m_values[sequenceIndex][rank];
}
template<typename T>
void TemplatedSequenceContext<T>::resetCache() {
m_rank = -1;
}
template<typename T>
bool TemplatedSequenceContext<T>::iterateUntilRank(int n, SequenceStore * sequenceStore, SequenceContext * sqctx) {
if (m_rank > n) {
m_rank = -1;
}
if (n < 0 || n-m_rank > k_maxRecurrentRank) {
return false;
}
while (m_rank++ < n) {
step(sequenceStore, sqctx);
}
m_rank--;
return true;
}
template<typename T>
void TemplatedSequenceContext<T>::step(SequenceStore * sequenceStore, SequenceContext * sqctx) {
/* Shift values */
for (int i = 0; i < MaxNumberOfSequences; i++) {
for (int j = MaxRecurrenceDepth; j > 0; j--) {
m_values[i][j] = m_values[i][j-1];
}
m_values[i][0] = NAN;
}
/* Evaluate new u(n) and v(n) */
Sequence * u = sequenceStore->numberOfFunctions() > 0 ? sequenceStore->functionAtIndex(0) : nullptr;
u = u && u->isDefined() ? u : nullptr;
Sequence * v = sequenceStore->numberOfFunctions() > 1 ? sequenceStore->functionAtIndex(1) : nullptr;
v = v && v->isDefined() ? v : nullptr;
/* Switch u & v if the name of u is v */
if (u != nullptr && u->name()[0] == SequenceStore::k_sequenceNames[1][0]) {
Sequence * temp = u;
u = v;
v = temp;
}
/* Approximate u & v at the new rank. We evaluate u twice in case its
* expression depends on v. */
m_values[0][0] = u ? u->approximateToNextRank<T>(m_rank, sqctx) : NAN;
m_values[1][0] = v ? v->approximateToNextRank<T>(m_rank, sqctx) : NAN;
m_values[0][0] = u ? u->approximateToNextRank<T>(m_rank, sqctx) : NAN;
}
template class TemplatedSequenceContext<float>;
template class TemplatedSequenceContext<double>;
}