NAME

log_sum_log_matrix_elements - Adds the elements of a matrix in log space

SYNOPSIS

#include "m/m_mat_arith.h"

Example compile flags (system dependent):
  -DLINUX_X86_64 -DLINUX_X86_64_OPTERON  -DGNU_COMPILER 
   -I/home/kobus/include
   -L/home/kobus/misc/load/linux_x86_64_opteron -L/usr/lib/x86_64-linux-gnu
  -lKJB                               -lfftw3  -lgsl -lgslcblas -ljpeg  -lSVM -lstdc++                    -lpthread -lSLATEC -lg2c    -lacml -lacml_mv -lblas -lg2c      -lncursesw 


double log_sum_log_matrix_elements(Matrix *log_mp);

DESCRIPTION

This routine returns the log of the sum of the anti-log (exp()) of the elements of the matrix pointed to by mp. This is done is a way which reduces problems due the possibility that the numbers are not well represented in non-log space. Think of the matrix being a log representation of some quantities. We want the sum of the non-log quantities, but we want the log representation of it. If needed, LOG_ZERO is used to represent log(0). LOG_ZERO is suffiently negative number that exp(LOG_ZERO) is zero.

RETURNS

log(sum(ew_exp(mp)) [ "ew" means element-wise ].

RELATED

sum_matrix_elements, average_matrix_elements)

DISCLAIMER

This software is not adequatedly tested. It is recomended that results are checked independantly where appropriate.

AUTHOR

Kobus Barnard

DOCUMENTER

Kobus Barnard

SEE ALSO

get_vector_outer_product , add_matrices , ow_add_matrices , ow_add_matrices_2 , subtract_matrices , ow_subtract_matrices , multiply_matrices_ew , ow_multiply_matrices_ew , ow_multiply_matrices_ew_2 , divide_matrices_ew , ow_divide_matrices_ew , ow_add_matrix_times_scalar , ow_add_matrix_times_scalar_2 , ow_add_int_matrix_to_matrix , multiply_matrices , multiply_by_transpose , multiply_with_transpose , multiply_by_own_transpose , get_dot_product_of_matrix_rows , get_dot_product_of_matrix_rows_2 , invert_matrix_elements , square_matrix_elements , exp_matrix_elements , log_matrix_elements , log_matrix_elements_2 , sqrt_matrix_elements , add_scalar_to_matrix , subtract_scalar_from_matrix , multiply_matrix_by_scalar , divide_matrix_by_scalar , ow_invert_matrix_elements , ow_square_matrix_elements , ow_exp_matrix_elements , ow_log_matrix_elements , ow_log_matrix_elements_2 , ow_add_scalar_to_matrix , ow_subtract_scalar_from_matrix , ow_multiply_matrix_by_scalar , ow_divide_matrix_by_scalar , multiply_vector_and_matrix , multiply_matrix_and_vector , multiply_matrix_rows , add_row_vector_to_matrix , subtract_row_vector_from_matrix , multiply_matrix_by_row_vector_ew , divide_matrix_by_row_vector , ow_add_row_vector_to_matrix , ow_subtract_row_vector_from_matrix , ow_multiply_matrix_by_row_vector_ew , ow_divide_matrix_by_row_vector , ow_add_vector_to_matrix_row , ow_add_vector_to_matrix_col , ow_add_scalar_times_vector_to_matrix_row , ow_subtract_vector_from_matrix_row , ow_multiply_matrix_row_by_vector , ow_divide_matrix_row_by_vector , ow_multiply_matrix_col_by_vector , ow_add_scalar_to_matrix_row , ow_subtract_scalar_from_matrix_row , ow_multiply_matrix_row_by_scalar , ow_divide_matrix_row_by_scalar , add_col_vector_to_matrix , ow_add_col_vector_to_matrix , subtract_col_vector_from_matrix , ow_subtract_col_vector_from_matrix , multiply_matrix_by_col_vector_ew , ow_multiply_matrix_by_col_vector_ew , divide_matrix_by_col_vector , ow_divide_matrix_by_col_vector , ow_add_matrix_row_times_scalar , ow_add_matrix_rows_ew , ow_multiply_matrix_rows_ew , sum_matrix_elements , sum_matrix_row_elements , sum_matrix_col_elements , average_matrix_elements , ow_subtract_identity_matrix , do_matrix_recomposition , do_matrix_recomposition_2 , ow_exp_scale_by_sum_log_matrix_row , ow_add_matrix_row_to_vector , ow_get_abs_of_matrix , get_abs_of_matrix , get_euler_rotation_matrix , get_euler_homo_rotation_matrix , get_3d_rotation_matrix_1 , get_3d_rotation_matrix_2 , get_2d_rotation_matrix , get_3d_homo_rotation_matrix_1 , get_3d_homo_rotation_matrix_2 , get_2d_homo_rotation_matrix , get_3d_scaling_matrix_1 , get_3d_scaling_matrix_2 , get_3d_homo_scaling_matrix_1 , get_3d_homo_scaling_matrix_2 , get_3d_homo_translation_matrix_1 , get_3d_homo_translation_matrix_2