Files
Upsilon/poincare/src/matrix.cpp
Romain Goyet a34ecd2769 [poincare] Use std::move when needed
When returning a subclass of an Expression as an Expression, make sure
to use std::move, otherwise the compiler cannot proceeed to copy
ellision.
2019-10-16 10:01:14 +02:00

460 lines
17 KiB
C++

#include <poincare/matrix.h>
#include <poincare/addition.h>
#include <poincare/division.h>
#include <poincare/exception_checkpoint.h>
#include <poincare/matrix_complex.h>
#include <poincare/matrix_layout.h>
#include <poincare/multiplication.h>
#include <poincare/rational.h>
#include <poincare/serialization_helper.h>
#include <poincare/subtraction.h>
#include <poincare/undefined.h>
#include <assert.h>
#include <cmath>
#include <float.h>
#include <stdlib.h>
#include <string.h>
#include <utility>
namespace Poincare {
static inline int minInt(int x, int y) { return x < y ? x : y; }
void MatrixNode::didAddChildAtIndex(int newNumberOfChildren) {
setNumberOfRows(1);
setNumberOfColumns(newNumberOfChildren);
}
int MatrixNode::polynomialDegree(Context * context, const char * symbolName) const {
return -1;
}
Layout MatrixNode::createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
assert(numberOfChildren() > 0);
MatrixLayout layout = MatrixLayout::Builder();
for (ExpressionNode * c : children()) {
layout.addChildAtIndex(c->createLayout(floatDisplayMode, numberOfSignificantDigits), layout.numberOfChildren(), layout.numberOfChildren(), nullptr);
}
layout.setDimensions(m_numberOfRows, m_numberOfColumns);
return std::move(layout);
}
int MatrixNode::serialize(char * buffer, int bufferSize, Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
if (bufferSize == 0) {
return -1;
}
buffer[bufferSize-1] = 0;
if (bufferSize == 1) {
return 0;
}
int currentChar = SerializationHelper::CodePoint(buffer, bufferSize, '[');
if (currentChar >= bufferSize-1) {
return currentChar;
}
for (int i = 0; i < m_numberOfRows; i++) {
currentChar += SerializationHelper::CodePoint(buffer + currentChar, bufferSize - currentChar, '[');
if (currentChar >= bufferSize-1) {
return currentChar;
}
currentChar += childAtIndex(i*m_numberOfColumns)->serialize(buffer+currentChar, bufferSize-currentChar, floatDisplayMode, numberOfSignificantDigits);
if (currentChar >= bufferSize-1) {
return currentChar;
}
for (int j = 1; j < m_numberOfColumns; j++) {
currentChar += SerializationHelper::CodePoint(buffer + currentChar, bufferSize - currentChar, ',');
if (currentChar >= bufferSize-1) {
return currentChar;
}
currentChar += childAtIndex(i*m_numberOfColumns+j)->serialize(buffer+currentChar, bufferSize-currentChar, floatDisplayMode, numberOfSignificantDigits);
if (currentChar >= bufferSize-1) {
return currentChar;
}
}
currentChar = strlen(buffer);
if (currentChar >= bufferSize-1) {
return currentChar;
}
currentChar += SerializationHelper::CodePoint(buffer + currentChar, bufferSize - currentChar, ']');
if (currentChar >= bufferSize-1) {
return currentChar;
}
}
currentChar += SerializationHelper::CodePoint(buffer + currentChar, bufferSize - currentChar, ']');
return minInt(currentChar, bufferSize-1);
}
template<typename T>
Evaluation<T> MatrixNode::templatedApproximate(Context * context, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit angleUnit) const {
MatrixComplex<T> matrix = MatrixComplex<T>::Builder();
for (ExpressionNode * c : children()) {
matrix.addChildAtIndexInPlace(c->approximate(T(), context, complexFormat, angleUnit), matrix.numberOfChildren(), matrix.numberOfChildren());
}
matrix.setDimensions(numberOfRows(), numberOfColumns());
return std::move(matrix);
}
// MATRIX
void Matrix::setDimensions(int rows, int columns) {
assert(rows * columns == numberOfChildren());
setNumberOfRows(rows);
setNumberOfColumns(columns);
}
void Matrix::addChildrenAsRowInPlace(TreeHandle t, int i) {
int previousNumberOfColumns = numberOfColumns();
if (previousNumberOfColumns > 0) {
assert(t.numberOfChildren() == numberOfColumns());
}
int previousNumberOfRows = numberOfRows();
for (int i = 0; i < t.numberOfChildren(); i++) {
addChildAtIndexInPlace(t.childAtIndex(i), numberOfChildren(), numberOfChildren());
}
setDimensions(previousNumberOfRows + 1, previousNumberOfColumns == 0 ? t.numberOfChildren() : previousNumberOfColumns);
}
int Matrix::rank(Context * context, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit angleUnit, bool inPlace) {
Matrix m = inPlace ? *this : clone().convert<Matrix>();
ExpressionNode::ReductionContext systemReductionContext = ExpressionNode::ReductionContext(context, complexFormat, angleUnit, ExpressionNode::ReductionTarget::System);
m = m.rowCanonize(systemReductionContext, nullptr);
int rank = m.numberOfRows();
int i = rank-1;
while (i >= 0) {
int j = m.numberOfColumns()-1;
while (j >= i && matrixChild(i,j).isRationalZero()) {
j--;
}
if (j == i-1) {
rank--;
} else {
break;
}
i--;
}
return rank;
}
template<typename T>
int Matrix::ArrayInverse(T * array, int numberOfRows, int numberOfColumns) {
if (numberOfRows != numberOfColumns) {
return -1;
}
assert(numberOfRows*numberOfColumns <= k_maxNumberOfCoefficients);
int dim = numberOfRows;
/* Create the matrix inv = (A|I) with A the input matrix and I the dim identity matrix
* (A is squared with less than k_maxNumberOfCoefficients so (A|I) has less than
* 2*k_maxNumberOfCoefficients */
T operands[2*k_maxNumberOfCoefficients];
for (int i = 0; i < dim; i++) {
for (int j = 0; j < dim; j++) {
operands[i*2*dim+j] = array[i*numberOfColumns+j];
}
for (int j = dim; j < 2*dim; j++) {
operands[i*2*dim+j] = j-dim == i ? 1.0 : 0.0;
}
}
ArrayRowCanonize(operands, dim, 2*dim);
// Check inversibility
for (int i = 0; i < dim; i++) {
if (std::abs(operands[i*2*dim+i] - (T)1.0) > Expression::Epsilon<float>()) {
return -2;
}
}
for (int i = 0; i < dim; i++) {
for (int j = 0; j < dim; j++) {
array[i*numberOfColumns+j] = operands[i*2*dim+j+dim];
}
}
return 0;
}
Matrix Matrix::rowCanonize(ExpressionNode::ReductionContext reductionContext, Expression * determinant) {
Expression::SetInterruption(false);
// The matrix children have to be reduced to be able to spot 0
deepReduceChildren(reductionContext);
Multiplication det = Multiplication::Builder();
int m = numberOfRows();
int n = numberOfColumns();
int h = 0; // row pivot
int k = 0; // column pivot
while (h < m && k < n) {
// Find the first non-null pivot
int iPivot = h;
while (iPivot < m && matrixChild(iPivot, k).isRationalZero()) {
iPivot++;
}
if (iPivot == m) {
// No non-null coefficient in this column, skip
k++;
if (determinant) {
// Update determinant: det *= 0
det.addChildAtIndexInPlace(Rational::Builder(0), det.numberOfChildren(), det.numberOfChildren());
}
} else {
// Swap row h and iPivot
if (iPivot != h) {
for (int col = h; col < n; col++) {
swapChildrenInPlace(iPivot*n+col, h*n+col);
}
if (determinant) {
// Update determinant: det *= -1
det.addChildAtIndexInPlace(Rational::Builder(-1), det.numberOfChildren(), det.numberOfChildren());
}
}
// Set to 1 M[h][k] by linear combination
Expression divisor = matrixChild(h, k);
// Update determinant: det *= divisor
if (determinant) {
det.addChildAtIndexInPlace(divisor.clone(), det.numberOfChildren(), det.numberOfChildren());
}
for (int j = k+1; j < n; j++) {
Expression opHJ = matrixChild(h, j);
Expression newOpHJ = Division::Builder(opHJ, divisor.clone());
replaceChildAtIndexInPlace(h*n+j, newOpHJ);
newOpHJ = newOpHJ.shallowReduce(reductionContext);
}
replaceChildInPlace(divisor, Rational::Builder(1));
/* Set to 0 all M[i][j] i != h, j > k by linear combination */
for (int i = 0; i < m; i++) {
if (i == h) { continue; }
Expression factor = matrixChild(i, k);
for (int j = k+1; j < n; j++) {
Expression opIJ = matrixChild(i, j);
Expression newOpIJ = Subtraction::Builder(opIJ, Multiplication::Builder(matrixChild(h, j).clone(), factor.clone()));
replaceChildAtIndexInPlace(i*n+j, newOpIJ);
newOpIJ.childAtIndex(1).shallowReduce(reductionContext);
newOpIJ = newOpIJ.shallowReduce(reductionContext);
}
replaceChildAtIndexInPlace(i*n+k, Rational::Builder(0));
}
h++;
k++;
}
}
if (determinant) {
*determinant = det;
}
return *this;
}
template<typename T>
void Matrix::ArrayRowCanonize(T * array, int numberOfRows, int numberOfColumns, T * determinant) {
int h = 0; // row pivot
int k = 0; // column pivot
while (h < numberOfRows && k < numberOfColumns) {
// Find the first non-null pivot
int iPivot = h;
while (iPivot < numberOfRows && std::abs(array[iPivot*numberOfColumns+k]) < Expression::Epsilon<double>()) {
iPivot++;
}
if (iPivot == numberOfRows) {
// No non-null coefficient in this column, skip
k++;
// Update determinant: det *= 0
if (determinant) { *determinant *= 0.0; }
} else {
// Swap row h and iPivot
if (iPivot != h) {
for (int col = h; col < numberOfColumns; col++) {
// Swap array[iPivot, col] and array[h, col]
T temp = array[iPivot*numberOfColumns+col];
array[iPivot*numberOfColumns+col] = array[h*numberOfColumns+col];
array[h*numberOfColumns+col] = temp;
}
// Update determinant: det *= -1
if (determinant) { *determinant *= -1.0; }
}
// Set to 1 array[h][k] by linear combination
T divisor = array[h*numberOfColumns+k];
// Update determinant: det *= divisor
if (determinant) { *determinant *= divisor; }
for (int j = k+1; j < numberOfColumns; j++) {
array[h*numberOfColumns+j] /= divisor;
}
array[h*numberOfColumns+k] = 1;
/* Set to 0 all M[i][j] i != h, j > k by linear combination */
for (int i = 0; i < numberOfRows; i++) {
if (i == h) { continue; }
T factor = array[i*numberOfColumns+k];
for (int j = k+1; j < numberOfColumns; j++) {
array[i*numberOfColumns+j] -= array[h*numberOfColumns+j]*factor;
}
array[i*numberOfColumns+k] = 0;
}
h++;
k++;
}
}
}
Matrix Matrix::CreateIdentity(int dim) {
Matrix matrix = Matrix::Builder();
for (int i = 0; i < dim; i++) {
for (int j = 0; j < dim; j++) {
matrix.addChildAtIndexInPlace(i == j ? Rational::Builder(1) : Rational::Builder(0), i*dim+j, i*dim+j);
}
}
matrix.setDimensions(dim, dim);
return matrix;
}
Matrix Matrix::createTranspose() const {
Matrix matrix = Matrix::Builder();
for (int j = 0; j < numberOfColumns(); j++) {
for (int i = 0; i < numberOfRows(); i++) {
matrix.addChildAtIndexInPlace(const_cast<Matrix *>(this)->matrixChild(i, j).clone(), matrix.numberOfChildren(), matrix.numberOfChildren());
}
}
// Intentionally swapping dimensions for transpose
matrix.setDimensions(numberOfColumns(), numberOfRows());
return matrix;
}
Expression Matrix::createInverse(ExpressionNode::ReductionContext reductionContext, bool * couldComputeInverse) const {
int dim = numberOfRows();
if (dim != numberOfColumns()) {
*couldComputeInverse = true;
return Undefined::Builder();
}
Expression result = computeInverseOrDeterminant(false, reductionContext, couldComputeInverse);
assert(!(*couldComputeInverse) || !result.isUninitialized());
return result;
}
Expression Matrix::determinant(ExpressionNode::ReductionContext reductionContext, bool * couldComputeDeterminant, bool inPlace) {
*couldComputeDeterminant = true;
Matrix m = inPlace ? *this : clone().convert<Matrix>();
int dim = m.numberOfRows();
if (dim != m.numberOfColumns()) {
// Determinant is for square matrices
return Undefined::Builder();
}
// Explicit formulas for dimensions from 1 to 3
if (dim == 1) {
// Determinant of [[a]] is a
return m.childAtIndex(0);
}
if (dim == 2) {
/* |a b|
* Determinant of |c d| is ad-bc */
Multiplication ad = Multiplication::Builder(m.matrixChild(0,0), m.matrixChild(1,1));
Multiplication bc = Multiplication::Builder(m.matrixChild(0,1), m.matrixChild(1,0));
Expression result = Subtraction::Builder(ad, bc);
ad.shallowReduce(reductionContext);
bc.shallowReduce(reductionContext);
return result;
}
if (dim == 3) {
/* |a b c|
* Determinant of |d e f| is aei+bfg+cdh-ceg-bdi-afh
* |g h i| */
Expression a = m.matrixChild(0,0);
Expression b = m.matrixChild(0,1);
Expression c = m.matrixChild(0,2);
Expression d = m.matrixChild(1,0);
Expression e = m.matrixChild(1,1);
Expression f = m.matrixChild(1,2);
Expression g = m.matrixChild(2,0);
Expression h = m.matrixChild(2,1);
Expression i = m.matrixChild(2,2);
constexpr int additionChildrenCount = 6;
Expression additionChildren[additionChildrenCount] = {
Multiplication::Builder(a.clone(), e.clone(), i.clone()),
Multiplication::Builder(b.clone(), f.clone(), g.clone()),
Multiplication::Builder(c.clone(), d.clone(), h.clone()),
Multiplication::Builder(Rational::Builder(-1), c, e, g),
Multiplication::Builder(Rational::Builder(-1), b, d, i),
Multiplication::Builder(Rational::Builder(-1), a, f, h)};
Expression result = Addition::Builder(additionChildren, additionChildrenCount);
for (int i = 0; i < additionChildrenCount; i++) {
additionChildren[i].shallowReduce(reductionContext);
}
return result;
}
// Dimension >= 4
Expression result = computeInverseOrDeterminant(true, reductionContext, couldComputeDeterminant);
assert(!(*couldComputeDeterminant) || !result.isUninitialized());
return result;
}
Expression Matrix::computeInverseOrDeterminant(bool computeDeterminant, ExpressionNode::ReductionContext reductionContext, bool * couldCompute) const {
assert(numberOfRows() == numberOfColumns());
int dim = numberOfRows();
/* If the matrix is too big, the rowCanonization might not be computed exactly
* because of a pool allocation error, but we might still be able to compute
* it approximately. We thus encapsulate the inverse/determinant creation in
* an exception checkpoint.
* We can safely use an exception checkpoint here because we are sure of not
* modifying any pre-existing node in the pool. We are sure there is no Store
* in the matrix. */
Poincare::ExceptionCheckpoint ecp;
if (ExceptionRun(ecp)) {
/* We clone the current matrix to extract its children later. We can't clone
* its children directly. Indeed, the current matrix node (this->node()) is
* located before the exception checkpoint. In order to clone its chidlren,
* we would temporary increase the reference counter of each child (also
* located before the checkpoint). If an exception is raised before
* destroying the child handle, its reference counter would be off by one
* after the long jump. */
Matrix cl = clone().convert<Matrix>();
*couldCompute = true;
/* Create the matrix (A|I) with A is the input matrix and I the dim
* identity matrix */
Matrix matrixAI = Matrix::Builder();
for (int i = 0; i < dim; i++) {
for (int j = 0; j < dim; j++) {
Expression mChildIJ = cl.matrixChild(i, j);
matrixAI.addChildAtIndexInPlace(mChildIJ, i*2*dim+j, i*2*dim+j);
}
for (int j = dim; j < 2*dim; j++) {
matrixAI.addChildAtIndexInPlace(j-dim == i ? Rational::Builder(1) : Rational::Builder(0), i*2*dim+j, i*2*dim+j);
}
}
matrixAI.setDimensions(dim, 2*dim);
if (computeDeterminant) {
// Compute the determinant
Expression d;
matrixAI.rowCanonize(reductionContext, &d);
return d;
}
// Compute the inverse
matrixAI = matrixAI.rowCanonize(reductionContext, nullptr);
// Check inversibility
for (int i = 0; i < dim; i++) {
if (!matrixAI.matrixChild(i, i).isRationalOne()) {
return Undefined::Builder();
}
}
Matrix inverse = Matrix::Builder();
for (int i = 0; i < dim; i++) {
for (int j = 0; j < dim; j++) {
inverse.addChildAtIndexInPlace(matrixAI.matrixChild(i, j+dim), i*dim+j, i*dim+j); // We can steal matrixAI's children
}
}
inverse.setDimensions(dim, dim);
return std::move(inverse);
} else {
*couldCompute = false;
return Expression();
}
}
template int Matrix::ArrayInverse<float>(float *, int, int);
template int Matrix::ArrayInverse<double>(double *, int, int);
template int Matrix::ArrayInverse<std::complex<float>>(std::complex<float> *, int, int);
template int Matrix::ArrayInverse<std::complex<double>>(std::complex<double> *, int, int);
template void Matrix::ArrayRowCanonize<std::complex<float> >(std::complex<float>*, int, int, std::complex<float>*);
template void Matrix::ArrayRowCanonize<std::complex<double> >(std::complex<double>*, int, int, std::complex<double>*);
}