Apostolos Fanakis
6 years ago
6 changed files with 256 additions and 134 deletions
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#include "sparse_matrix.h" |
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SparseMatrix createSparseMatrix() { |
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SparseMatrix sparseMatrix; |
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sparseMatrix.elements = 0; |
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sparseMatrix.firstElement = NULL; |
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return sparseMatrix; |
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} |
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void apendElement(SparseMatrix *sparseMatrix, double value, int row, int column) { |
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// Creates the new element
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SparseMatrixElement *newElement = (SparseMatrixElement *) malloc(sizeof(SparseMatrixElement)); |
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newElement->value = value; |
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newElement->rowIndex = row; |
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newElement->columnIndex = column; |
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newElement->nextElement = NULL; |
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if (sparseMatrix->firstElement == NULL) { |
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// Sparse matrix is empty, this is the first element
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sparseMatrix->firstElement = newElement; |
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} else { |
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//Gets last element of the matrix
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SparseMatrixElement *lastElement = sparseMatrix->firstElement; |
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while (lastElement->nextElement != NULL) { |
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lastElement = lastElement->nextElement; |
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} |
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lastElement->nextElement = newElement; |
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} |
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sparseMatrix->elements = sparseMatrix->elements + 1; |
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} |
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bool deleteElement(SparseMatrix *sparseMatrix, int row, int column) { |
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if (sparseMatrix->elements == 0) { |
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// Matrix is empty, nothing can be deleted
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return false; |
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} else if (sparseMatrix->elements == 1) { |
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// Matrix has one element. Deletes it.
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free(sparseMatrix->firstElement); |
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sparseMatrix->firstElement = NULL; |
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sparseMatrix->elements = sparseMatrix->elements - 1; |
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return true; |
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} |
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SparseMatrixElement *currentElement = sparseMatrix->firstElement; |
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if (currentElement->rowIndex == row && currentElement->columnIndex == column) { |
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sparseMatrix->firstElement = currentElement->nextElement; |
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free(currentElement); |
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sparseMatrix->elements = sparseMatrix->elements - 1; |
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return true; |
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} |
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// Matrix has multiple elements. Finds the first element that has the coordinates
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// (row,column) and deletes it.
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for (int i=0; i<sparseMatrix->elements - 1; ++i) { |
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SparseMatrixElement *nextElement = currentElement->nextElement; |
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if (nextElement->rowIndex == row && nextElement->columnIndex == column) { |
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currentElement->nextElement = nextElement->nextElement; |
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free(nextElement); |
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sparseMatrix->elements = sparseMatrix->elements - 1; |
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return true; |
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} else { |
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currentElement = currentElement->nextElement; |
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} |
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} |
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} |
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SparseMatrixElement *getElement(SparseMatrix sparseMatrix, int row, int column) { |
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SparseMatrixElement *currentElement = sparseMatrix.firstElement; |
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do { |
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if (currentElement->rowIndex == row && currentElement->columnIndex == column) { |
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return currentElement; |
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} |
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currentElement = currentElement->nextElement; |
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} while (currentElement != NULL); |
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return NULL; |
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} |
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void transposeSparseMatrix(SparseMatrix *sparseMatrix) { |
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SparseMatrixElement *currentElement = sparseMatrix->firstElement; |
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for (int i=0; i<sparseMatrix->elements; ++i) { |
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int temp = currentElement->rowIndex; |
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currentElement->rowIndex = currentElement->columnIndex; |
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currentElement->columnIndex = temp; |
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currentElement = currentElement->nextElement; |
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} |
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} |
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void sparseMatrixVectorMultiplication(SparseMatrix sparseMatrix, |
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double *vector, double **product, int vectorSize) { |
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// Initializes the elements of the product vector to zero
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for (int i=0; i<vectorSize; ++i) { |
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(*product)[i] = 0; |
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} |
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SparseMatrixElement *element = sparseMatrix.firstElement; |
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for (int i=0; i<sparseMatrix.elements; ++i) { |
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int row = element->rowIndex, column = element->columnIndex; |
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if (row >= vectorSize) { |
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printf("Error at sparseMatrixVectorMultiplication. Matrix has more rows than vector!\n"); |
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printf("row = %d\n", row); |
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exit(EXIT_FAILURE); |
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} |
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(*product)[row] = (*product)[row] + element->value * vector[column]; |
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element = element->nextElement; |
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} |
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} |
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void printSparseMatrix(SparseMatrix sparseMatrix) { |
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if (sparseMatrix.elements == 0) { |
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return; |
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} |
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SparseMatrixElement *currentElement = sparseMatrix.firstElement; |
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for (int i=0; i<sparseMatrix.elements; ++i) { |
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printf("[%d,%d] = %f\n", currentElement->rowIndex, |
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currentElement->columnIndex, currentElement->value); |
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currentElement = currentElement->nextElement; |
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} |
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} |
@ -0,0 +1,29 @@ |
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#ifndef SPARSE_MATRIX_H /* Include guard */ |
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#define SPARSE_MATRIX_H |
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#include <stdbool.h> |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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typedef struct sparseMatrixElement { |
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double value; |
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int rowIndex, columnIndex; |
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struct sparseMatrixElement *nextElement; |
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} SparseMatrixElement; |
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typedef struct sparseMatrix { |
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int elements; |
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SparseMatrixElement *firstElement; |
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} SparseMatrix; |
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SparseMatrix createSparseMatrix(); |
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void apendElement(SparseMatrix *sparseMatrix, double value, int row, int column); |
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bool deleteElement(SparseMatrix *sparseMatrix, int row, int column); |
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SparseMatrixElement *getElement(SparseMatrix sparseMatrix, int row, int column); |
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void transposeSparseMatrix(SparseMatrix *sparseMatrix); |
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void sparseMatrixVectorMultiplication(SparseMatrix sparseMatrix, double *vector, |
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double **product, int vectorSize); |
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void printSparseMatrix(SparseMatrix sparseMatrix); |
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#endif // SPARSE_MATRIX_H
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