utilities.h

utilities.h#

Header file for miscellaneous utility functions.

Author: Rahil Makadia makadia2@illinois.edu

LICENSE#

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, see https://www.gnu.org/licenses.

Defines

real#: Real type to be used for floating point calculations. Choose between double and long double.

PI#: Value of PI.

RAD2DEG#: Conversion factor from radians to degrees.

DEG2RAD#: Conversion factor from degrees to radians.

EARTH_OBLIQUITY#: Value of Earth’s obliquity in radians.

EARTH_RAD_WGS84#: Value of Earth’s WGS84 radius in AU.

EARTH_FLAT_WGS84#: Value of Earth’s WGS84 flattening.

Functions

void wrap_to_2pi(real &angle)#

Wrap an angle to the range [0, 2*pi).

Parameters:: angle – [inout] Angle to be wrapped.

void rad_to_deg(const real &rad, real &deg)#

Convert an angle from radians to degrees.

Parameters:

rad – [in] Angle in radians.
deg – [out] Angle in degrees.

real rad_to_deg(const real rad)#

Convert an angle from radians to degrees.

Parameters:: rad – [in] Angle in radians.
Returns:: real Angle in degrees.

void deg_to_rad(const real &deg, real &rad)#

Convert an angle from degrees to radians.

Parameters:

deg – [in] Angle in degrees.
rad – [out] Angle in radians.

real deg_to_rad(const real deg)#

Convert an angle from degrees to radians.

Parameters:: deg – [in] Angle in degrees.
Returns:: real Angle in radians.

void sort_vector(std::vector<real> &v, const bool &ascending, std::vector<size_t> &sortedIdx)#

Sort a vector in ascending or descending order.

Parameters:

v – [inout] Vector to be sorted.
ascending – [in] True for ascending order, false for descending order.
sortedIdx – [out] Vector of sorted indices from the original vector.

void sort_vector_by_idx(std::vector<std::vector<real>> &v, const std::vector<size_t> &sortedIdx)#

Sort a vector of vectors based on the indices of another vector.

Parameters:

v – [inout] Vector of vectors to be sorted.
sortedIdx – [in] Vector of sorted indices.

void vdot(const std::vector<real> &v1, const std::vector<real> &v2, real &dot)#

Dot product of two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
dot – [out] Dot product of v1 and v2.

void vdot(const real *v1, const real *v2, const size_t &dim, real &dot)#

Dot product of two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
dim – [in] Dimension of the vectors.
dot – [out] Dot product of v1 and v2.

void vnorm(const std::vector<real> &v, real &norm)#

Norm of a vector.

Parameters:

v – [in] Vector.
norm – [out] Norm of v.

void vnorm(const real *v, const size_t &dim, real &norm)#

Norm of a vector.

Parameters:

v – [in] Vector.
dim – [in] Dimension of the vector.
norm – [out] Norm of v.

void vunit(const std::vector<real> &v, std::vector<real> &unit)#

Unit vector of a vector.

Parameters:

v – [in] Vector.
vunit – [out] Unit vector of v.

void vunit(const real *v, const size_t &dim, real *unit)#

Unit vector of a vector.

Parameters:

v – [in] Vector.
dim – [in] Dimension of the vector.
unit – [out] Unit vector of v.

void vcross(const std::vector<real> &v1, const std::vector<real> &v2, std::vector<real> &cross)#

Cross product of two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
v3 – [out] Cross product of v1 and v2.

void vcross(const real *v1, const real *v2, real *cross)#

Cross product of two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
v3 – [out] Cross product of v1 and v2.

void vadd(const std::vector<real> &v1, const std::vector<real> &v2, std::vector<real> &sum)#

Add two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
v3 – [out] Sum of v1 and v2.

void vsub(const std::vector<real> &v1, const std::vector<real> &v2, std::vector<real> &diff)#

Subtract two vectors.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
v3 – [out] Difference of v1 and v2.

void vcmul(const std::vector<real> &v, const real &c, std::vector<real> &vc)#

Multiply a vector by a constant.

Parameters:

v – [in] Vector.
c – [in] Constant.
vc – [out] Product of v and c.

void vvmul(const std::vector<real> &v1, const std::vector<real> &v2, std::vector<real> &v3)#

Multiply two vectors element-wise.

Parameters:

v1 – [in] Vector 1.
v2 – [in] Vector 2.
v3 – [out] Element-wise product of v1 and v2.

void vabs_max(const std::vector<real> &v, real &max)#

Find the maximum absolute value in a vector.

Parameters:

v – [in] Vector.
max – [out] Maximum absolute value in v.

void vabs_max(const real *v, const size_t &dim, real &max)#

Find the maximum absolute value in a vector.

Parameters:

v – [in] Vector.
dim – [in] Dimension of the vector.
max – [out] Maximum absolute value in v.

void mat_vec_mul(const std::vector<std::vector<real>> &A, const std::vector<real> &v, std::vector<real> &Av)#

Multiply a matrix by a vector.

Parameters:

A – [in] Matrix.
v – [in] Vector.
Av – [out] Product of A and v.

void vec_mat_mul(const std::vector<real> &v, real **A, const size_t &dim, std::vector<real> &vA)#

Multiply a vector by a matrix.

Parameters:

v – [in] Vector.
A – [in] Matrix.
dim – [in] Dimension of the vector and matrix.
vA – [out] Product of v and A.

void mat_mat_mul(const std::vector<std::vector<real>> &A, const std::vector<std::vector<real>> &B, std::vector<std::vector<real>> &AB)#

Multiply two matrices.

Parameters:

A – [in] Matrix 1.
B – [in] Matrix 2.
AB – [out] Product of A and B.

void mat3_inv(const std::vector<std::vector<real>> &A, std::vector<std::vector<real>> &Ainv)#

Invert a 3x3 matrix.

Parameters:

A – [in] Matrix to be inverted.
Ainv – [out] Inverted matrix.

void mat3_mat3_mul(const real *A, const real *B, real *prod)#

Multiply two 3x3 matrices.

Parameters:

A – [in] Matrix 1.
B – [in] Matrix 2.
prod – [out] Product of A and B.

void mat3_mat3_add(const real *A, const real *B, real *sum)#

Add two 3x3 matrices.

Parameters:

A – [in] Matrix 1.
B – [in] Matrix 2.
sum – [out] Sum of A and B.

void rot_mat_x(const real &theta, std::vector<std::vector<real>> &R)#

Rotation matrix about the x-axis.

Parameters:

theta – [in] Angle of rotation in radians.
R – [out] Rotation matrix.

void rot_mat_y(const real &theta, std::vector<std::vector<real>> &R)#

Rotation matrix about the y-axis.

Parameters:

theta – [in] Angle of rotation in radians.
R – [out] Rotation matrix.

void rot_mat_z(const real &theta, std::vector<std::vector<real>> &R)#

Rotation matrix about the z-axis.

Parameters:

theta – [in] Angle of rotation in radians.
R – [out] Rotation matrix.

void LU_decompose(std::vector<std::vector<real>> &A, const size_t &N, const real &tol, size_t *P)#

Decompose a matrix into its LU form.

Parameters:

A – [inout] Matrix to be decomposed.
N – [in] Size of the matrix.
tol – [in] Tolerance for degeneracy.
P – [out] Permutation matrix.

void LU_inverse(std::vector<std::vector<real>> &A, const size_t *P, const size_t &N, std::vector<std::vector<real>> &AInv)#

Invert a matrix using its LU decomposition.

Parameters:

A – [in] Matrix to be inverted.
P – [in] Permutation matrix.
N – [in] Size of the matrix.
AInv – [out] Inverted matrix.

void mat_inv(std::vector<std::vector<real>> mat, std::vector<std::vector<real>> &matInv, const real &tol = 1.0e-16L)#

Invert a matrix.

Parameters:

mat – [in] Matrix to be inverted.
matInv – [out] Inverted matrix.
tol – [in] Tolerance for degeneracy.

utilities.h

Contents

utilities.h#

LICENSE#