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3D Matrix Algebra Functions

Note: this is not to be confused with the general matrix algebra package.

3D Matrices are structures containing a 3 by 3 float array (try not to use this). Functions usually pass matrices by value and return matrices. Again the convenience is worth the overhead.

void *mat3_alloc()
Returns pointer to a newly allocated zero matrix.

void *mat3_make(Mat3 m)
Returns pointer to a newly allocated copy of m.

void mat3_free(Mat3 *m)
Frees an allocated matrix (for completeness, just calls rfree).

Mat3    mat3(double mxx, double mxy, double mxz,
             double myx, double myy, double myz,
             double mzx, double mzy, double mzz)
Returns matrix with given components (arguments in row order).

Mat3 mat3_unit()
Returns unit matrix.

Mat3 mat3_zero()
Returns zero matrix.

Macro mat3_xx()

Macro mat3_xy()

Macro mat3_zz()
Macros to return components of matrix (can be used on left and right hand sides of assignment statements).

double mat3_get_xx()

double mat3_get_xy()


double mat3_get_zz()
Return components of matrix (function versions of above macros).

void    mat3_comps(Mat3 m, float *mxx, float *mxy, float *mxz,
                           float *myx, float *myy, float *myz,
                           float *mzx, float *mzy, float *mzz)
Sets *mxx etc. to components of matrix m.

Vec3 mat3_rowx(Mat3 m)

Vec3 mat3_rowy(Mat3 m)

Vec3 mat3_rowz(Mat3 m)
Return rows of matrix as Vec3's.

Vec3 mat3_colx(Mat3 m)

Vec3 mat3_coly(Mat3 m)

Vec3 mat3_colz(Mat3 m)
Return columns of matrix as Vec3's.

Mat3 mat3_of_cols(Vec3 cx, Vec3 cy, Vec3 cz)
Returns matrix with given column vectors.

Mat3 mat3_of_rows(Vec3 rx, Vec3 ry, Vec3 rz)
Returns matrix with given row vectors.

Mat3 mat3_sum(Mat3 m, Mat3 n)
Returns sum m+n of two matrices.

Mat3 mat3_diff(Mat3 m, Mat3 n)
Returns difference m-n of two matrices.

Mat3 mat3_minus(Mat3 m)
Returns negative -m of matrix.

Mat3 mat3_times(double k, Mat3 m)
Returns (matrix) product km of a scalar and a matrix.

Mat3 mat3_prod(Mat3 m, Mat3 n)
Returns matrix product mn of two matrices.

Mat3 mat3_inverse(Mat3 m)
Returns inverse of a matrix (algorithm is usually plenty good enough for 3 by 3's).

Mat3 mat3_transpose(Mat3 m)
Returns transpose of a matrix.

double mat3_trace(Mat3 m)
Returns trace (sum of diagonal elements).

double mat3_det(Mat3 m)
Returns determinant of matrix.

Bool mat3_posdef(Mat3 m)
Returns true if symmetric matrix is positive definite.
Vec3 mat3_vprod(Mat3 m, Vec3 v)

Returns (vector) product mv of matrix and vector.

Vec3 mat3_transpose_vprod(Mat3 m, Vec3 v)
Returns (vector) product m'v of transpose of matrix and vector.

double mat3_sprod(Vec3 v, Mat3 m, Vec3 w)
Returns (scalar) contraction v'mw of matrix with two vectors.

Mat3    mat3_tensor(Vec3 v, Vec3 w)
Returns (matrix) tensor product mij = vi*vj of two vectors.

Mat3    mat3_read(FILE *fp)
Returns matrix read from ascii file.

void    mat3_print(Mat3 fp, FILE *m)
Prints matrix to ascii file.

void    mat3_pprint(FILE * fp, char *msg, Mat3 m)
Prints matrix (with introductory message) to ascii file.

void    mat3_format(Mat3 m)
Prints matrix to Tina format output (stdio or main textsw).

void    mat3_eigen(Mat3 m, double *eval, Vec3 * evec)
Returns the eigen values and eigen vectors of the matrix.

next up previous contents
Next: 2D Vector Algebra Functions Up: 2D and 3D vector Previous: 3D Vector Geometry   Contents
root 2019-03-24