library(matlib)
## Warning: package 'matlib' was built under R version 4.2.3
A <- matrix(c(9,-2,3,4,6,-4,6,-2,5,-3,9,-1,6,-7,2,-4),4,4)
B <- c(4,6,3,6)
A
##      [,1] [,2] [,3] [,4]
## [1,]    9    6    5    6
## [2,]   -2   -4   -3   -7
## [3,]    3    6    9    2
## [4,]    4   -2   -1   -4
B
## [1] 4 6 3 6
showEqn(A,B)
##  9*x1 + 6*x2 + 5*x3 + 6*x4  =  4 
## -2*x1 - 4*x2 - 3*x3 - 7*x4  =  6 
##  3*x1 + 6*x2 + 9*x3 + 2*x4  =  3 
##  4*x1 - 2*x2 - 1*x3 - 4*x4  =  6

Model linear-Gaussian adalah jaringan Bayes dimana semua variabel adalah Gaussian, dan rata-rata setiap variabel adalah linear dalam nilai induknya. Banyak digunakan karena mendukung inferensi yang efisien. Sistem dinamik linear adalah kasus Khusus yang penting

echelon(A, B, verbose=TRUE, fractions=TRUE)
## 
## Initial matrix:
##      [,1] [,2] [,3] [,4] [,5]
## [1,]  9    6    5    6    4  
## [2,] -2   -4   -3   -7    6  
## [3,]  3    6    9    2    3  
## [4,]  4   -2   -1   -4    6  
## 
## row: 1 
## 
##  multiply row 1 by 1/9 
##      [,1] [,2] [,3] [,4] [,5]
## [1,]   1  2/3  5/9  2/3  4/9 
## [2,]  -2   -4   -3   -7    6 
## [3,]   3    6    9    2    3 
## [4,]   4   -2   -1   -4    6 
## 
##  multiply row 1 by 2 and add to row 2 
##      [,1]  [,2]  [,3]  [,4]  [,5] 
## [1,]     1   2/3   5/9   2/3   4/9
## [2,]     0  -8/3 -17/9 -17/3  62/9
## [3,]     3     6     9     2     3
## [4,]     4    -2    -1    -4     6
## 
##  multiply row 1 by 3 and subtract from row 3 
##      [,1]  [,2]  [,3]  [,4]  [,5] 
## [1,]     1   2/3   5/9   2/3   4/9
## [2,]     0  -8/3 -17/9 -17/3  62/9
## [3,]     0     4  22/3     0   5/3
## [4,]     4    -2    -1    -4     6
## 
##  multiply row 1 by 4 and subtract from row 4 
##      [,1]  [,2]  [,3]  [,4]  [,5] 
## [1,]     1   2/3   5/9   2/3   4/9
## [2,]     0  -8/3 -17/9 -17/3  62/9
## [3,]     0     4  22/3     0   5/3
## [4,]     0 -14/3 -29/9 -20/3  38/9
## 
## row: 2 
## 
##  exchange rows 2 and 4 
##      [,1]  [,2]  [,3]  [,4]  [,5] 
## [1,]     1   2/3   5/9   2/3   4/9
## [2,]     0 -14/3 -29/9 -20/3  38/9
## [3,]     0     4  22/3     0   5/3
## [4,]     0  -8/3 -17/9 -17/3  62/9
## 
##  multiply row 2 by -3/14 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1    2/3    5/9    2/3    4/9
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      4   22/3      0    5/3
## [4,]      0   -8/3  -17/9  -17/3   62/9
## 
##  multiply row 2 by 2/3 and subtract from row 1 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1      0   2/21   -2/7  22/21
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      4   22/3      0    5/3
## [4,]      0   -8/3  -17/9  -17/3   62/9
## 
##  multiply row 2 by 4 and subtract from row 3 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1      0   2/21   -2/7  22/21
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      0   32/7  -40/7   37/7
## [4,]      0   -8/3  -17/9  -17/3   62/9
## 
##  multiply row 2 by 8/3 and add to row 4 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1      0   2/21   -2/7  22/21
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      0   32/7  -40/7   37/7
## [4,]      0      0  -1/21  -13/7  94/21
## 
## row: 3 
## 
##  multiply row 3 by 7/32 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1      0   2/21   -2/7  22/21
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      0      1   -5/4  37/32
## [4,]      0      0  -1/21  -13/7  94/21
## 
##  multiply row 3 by 2/21 and subtract from row 1 
##      [,1]   [,2]   [,3]   [,4]   [,5]  
## [1,]      1      0      0   -1/6  15/16
## [2,]      0      1  29/42   10/7 -19/21
## [3,]      0      0      1   -5/4  37/32
## [4,]      0      0  -1/21  -13/7  94/21
## 
##  multiply row 3 by 29/42 and subtract from row 2 
##      [,1]    [,2]    [,3]    [,4]    [,5]   
## [1,]       1       0       0    -1/6   15/16
## [2,]       0       1       0   55/24 -109/64
## [3,]       0       0       1    -5/4   37/32
## [4,]       0       0   -1/21   -13/7   94/21
## 
##  multiply row 3 by 1/21 and add to row 4 
##      [,1]    [,2]    [,3]    [,4]    [,5]   
## [1,]       1       0       0    -1/6   15/16
## [2,]       0       1       0   55/24 -109/64
## [3,]       0       0       1    -5/4   37/32
## [4,]       0       0       0  -23/12  145/32
## 
## row: 4 
## 
##  multiply row 4 by -12/23 
##      [,1]     [,2]     [,3]     [,4]     [,5]    
## [1,]        1        0        0     -1/6    15/16
## [2,]        0        1        0    55/24  -109/64
## [3,]        0        0        1     -5/4    37/32
## [4,]        0        0        0        1 -435/184
## 
##  multiply row 4 by 1/6 and add to row 1 
##      [,1]     [,2]     [,3]     [,4]     [,5]    
## [1,]        1        0        0        0    25/46
## [2,]        0        1        0    55/24  -109/64
## [3,]        0        0        1     -5/4    37/32
## [4,]        0        0        0        1 -435/184
## 
##  multiply row 4 by 55/24 and subtract from row 2 
##      [,1]     [,2]     [,3]     [,4]     [,5]    
## [1,]        1        0        0        0    25/46
## [2,]        0        1        0        0 1367/368
## [3,]        0        0        1     -5/4    37/32
## [4,]        0        0        0        1 -435/184
## 
##  multiply row 4 by 5/4 and add to row 3 
##      [,1]     [,2]     [,3]     [,4]     [,5]    
## [1,]        1        0        0        0    25/46
## [2,]        0        1        0        0 1367/368
## [3,]        0        0        1        0 -331/184
## [4,]        0        0        0        1 -435/184