Soikk 7603bfcadc Bug fixes, UI fixes
You can now raise a matrix to a negative power and store the resulting matrixes from an operation with a scalar in another matrix
2021-10-25 00:52:13 +02:00

248 lines
7.1 KiB
C

#include "matrix-operations.h"
matrix_t matrixError(error_t error){
switch(error){
case NOT_EQUAL:
perror("Matrices are not of the same dimensions\n");
break;
case NOT_MULTIPLIABLE:
perror("Matrix A's number of columns is different to matrix B's number of rows\n");
break;
case NOT_SQUARE:
perror("Matrix is not square");
break;
case ZERO_DET:
perror("Determinant of the matrix should be 0\n");
break;
case UNKNOWN:
default:
perror("Unknown error\n");
}
return createMatrix(0, 0);
}
// Creates a rows x columns matrix;
matrix_t createMatrix(size_t rows, size_t columns){
matrix_t newmatrix;
newmatrix.rows = rows;
newmatrix.columns = columns;
newmatrix.matrix = malloc(rows*sizeof(float*));
for(size_t i = 0; i < rows; ++i)
newmatrix.matrix[i] = calloc(columns,sizeof(float));
return newmatrix;
}
// Fills the matrix with values provided by the user
void initializeMatrix(matrix_t *m){
printf("Initializing %dx%d matrix\n", m->rows, m->columns);
for(size_t r = 0; r < m->rows; ++r){
printf("Please insert %d numbers for each of the columns of the %d%s row\n",
m->columns, r+1, (r+1==1)?("st"):((r+1==2)?("nd"):((r+1==3)?("rd"):("th"))));
for(size_t c = 0; c < m->columns; ++c){
scanf("%f", &m->matrix[r][c]);
}
}
}
// Returns true if the matrix is square, false otherwise
int isSquare(matrix_t m){
return m.rows == m.columns;
}
// Displays the given matrix
void displayMatrix(matrix_t m){
for(size_t r = 0; r < m.rows; ++r){
for(size_t c = 0; c < m.columns; ++c)
printf("%3.3g ", m.matrix[r][c]);
printf("\n");
}
}
// Returns the identity matrix n x n
matrix_t identityMatrix(size_t n){
matrix_t identityMatrix = createMatrix(n, n);
for(size_t r = 0; r < n; ++r)
for(size_t c = 0; c < n; ++c)
if(r == c)
identityMatrix.matrix[r][c] = 1;
return identityMatrix;
}
// Returns a matrix of the same size as "m" filled with the number "n"
matrix_t fillN(matrix_t m, float n){
matrix_t filledmatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r)
for(size_t c = 0; c < m.columns; ++c)
filledmatrix.matrix[r][c] = n;
return filledmatrix;
}
// Adds a number to all the positions of the matrix and returns the result
matrix_t addN(matrix_t m, float n){
matrix_t addedmatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r)
for(size_t c = 0; c < m.columns; ++c)
addedmatrix.matrix[r][c] = m.matrix[r][c]+n;
return addedmatrix;
}
// Substracts a number from all the positions of the matrix and returns the result
matrix_t substractN(matrix_t m, float n){
matrix_t substractedmatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r)
for(size_t c = 0; c < m.columns; ++c)
substractedmatrix.matrix[r][c] = m.matrix[r][c]-n;
return substractedmatrix;
}
// Adds two matrices together and returns the result
matrix_t addMatrices(matrix_t a, matrix_t b){
if(a.rows != b.rows || a.columns != b.columns)
return matrixError(NOT_EQUAL);
matrix_t addedmatrices = createMatrix(a.rows, b.columns);
for(size_t r = 0; r < a.rows; ++r)
for(size_t c = 0; c < a.columns; ++c)
addedmatrices.matrix[r][c] = a.matrix[r][c] + b.matrix[r][c];
return addedmatrices;
}
// Negates all of the positions of the matrix and returns the result
matrix_t negateMatrix(matrix_t m){
matrix_t negatedmatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r)
for(size_t c = 0; c < m.columns; ++c)
negatedmatrix.matrix[r][c] = -m.matrix[r][c];
return negatedmatrix;
}
// Substracts matrix "b" from "a" and returns the result
matrix_t substractMatrices(matrix_t a, matrix_t b){
return addMatrices(a, negateMatrix(b));
}
// Multiplies all of the positions of the matrix by "n" and returns the result
matrix_t multiplyByN(matrix_t m, float n){
matrix_t multipliedmatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r)
for(size_t c = 0; c < m.columns; ++c)
multipliedmatrix.matrix[r][c] = m.matrix[r][c]*n;
return multipliedmatrix;
}
// Divides all of the positions of the matrix by "n" and returns the result
matrix_t divideByN(matrix_t m, float n){
return multiplyByN(m, (float)1/n);
}
// Multiplies matrix "a" by "b" and returns the result
matrix_t multiplyMatrices(matrix_t a, matrix_t b){
if(a.columns != b.rows)
return matrixError(NOT_MULTIPLIABLE);
matrix_t multipliedmatrices = createMatrix(a.rows, b.columns);
for(size_t r = 0; r < multipliedmatrices.rows; ++r)
for(size_t c = 0; c < multipliedmatrices.columns; ++c)
for(size_t n = 0; n < a.columns; ++n)
multipliedmatrices.matrix[r][c] += a.matrix[r][n]*b.matrix[n][c];
return multipliedmatrices;
}
// Divides matrix "a" by "b" and returns the result
matrix_t divideMatrices(matrix_t a, matrix_t b){
return multiplyMatrices(a, inverse(b));
}
// Raises the matrix to the nth power and returns the result
matrix_t raiseMatrixToN(matrix_t m, int n){
if(!isSquare(m))
return matrixError(NOT_SQUARE);
matrix_t raisedmatrix = identityMatrix(m.rows);
if(n < 0){
m = inverse(m);
n = -n;
}
for(int i = 0; i < n; ++i)
raisedmatrix = multiplyMatrices(raisedmatrix, m);
return raisedmatrix;
}
// Creates a submatrix from "matrix" without the column "column" and row "row" of "matrix"
matrix_t createSubmatrix(matrix_t m, size_t row, size_t column){
// TODO: not remove any
int mod = m.rows, nmod = mod-1, sr = 0, sc = 0;
matrix_t submatrix = createMatrix(nmod, nmod);
for(size_t r = 0; r < mod; ++r){
sc = 0;
if(r != row){
for(size_t c = 0; c < mod; ++c){
if(c != column){
submatrix.matrix[sr][sc] = m.matrix[r][c];
++sc;
}
}
++sr;
}
}
return submatrix;
}
// Returns the determinant of the given (square) matrix
int determinant(matrix_t m){
if(!isSquare(m)){
matrixError(NOT_SQUARE);
return (int)NULL;
}
int det = 0;
if(m.rows == 1)
return m.matrix[0][0];
else{
int count = 0, nmod = m.rows-1;
for(size_t r = 0; r < m.rows; ++r){
matrix_t submatrix = createSubmatrix(m, 0, r);
int subdeterminant = determinant(submatrix);
int step = m.matrix[0][r]*subdeterminant;
if((count++)%2 == 0)
det += step;
else
det -= step;
}
return det;
}
}
// Returns the cofactor matrix of the given matrix
matrix_t cofactor(matrix_t m){
if(!isSquare(m))
return matrixError(NOT_SQUARE);
matrix_t cofactormatrix = createMatrix(m.rows, m.columns);
for(size_t r = 0; r < m.rows; ++r){
for(size_t c = 0; c < m.columns; ++c){
matrix_t submatrix = createSubmatrix(m, r, c);
int d = determinant(submatrix);
cofactormatrix.matrix[r][c] = (r+c)%2?-d:d;
}
}
return cofactormatrix;
}
// Returns the transpose matrix of the given matrix
matrix_t transpose(matrix_t m){
matrix_t transposematrix = createMatrix(m.columns, m.rows);
for(size_t r = 0; r < m.columns; ++r)
for(size_t c = 0; c < m.rows; ++c)
transposematrix.matrix[r][c] = m.matrix[c][r];
return transposematrix;
}
// Returns the adjugate matrix of the given matrix
matrix_t adjugate(matrix_t m){
return transpose(cofactor(m));
}
// Returns the inverse matrix of the given matrix
matrix_t inverse(matrix_t m){
int det = determinant(m);
if(det == 0)
return matrixError(ZERO_DET);
return divideByN(adjugate(m), det);
}