Improve consistency of Julia code for Gaussian elimination (#269)

- rename gauss_jordan function to gauss_jordan_elimination
- do gauss_jordan_elimination in-place, to match with gaussian_elimination

Author: mika314

chapters/algorithms/gaussian_elimination/code/julia/gaussian_elimination.jl

@@ -67,7 +67,7 @@ function back_substitution(A::Array{Float64,2})
 end
 
 
-function gauss_jordan(A::Array{Float64,2})
+function gauss_jordan_elimination(A::Array{Float64,2})
 
     rows = size(A,1)
     cols = size(A,2)
@@ -83,7 +83,7 @@ function gauss_jordan(A::Array{Float64,2})
             for i = cols:-1:col
                 A[row,i] /= A[row,col]
             end
-    
+
             # subtract value from above row and set values above pivot to 0
             for i = 1:row-1
                 for j = cols:-1:col
@@ -93,8 +93,6 @@ function gauss_jordan(A::Array{Float64,2})
             row += 1
         end
     end
-
-    return A
 end
 
 function main()
@@ -105,8 +103,8 @@ function main()
     gaussian_elimination(A)
     println(A)
 
-    reduced = gauss_jordan(A)
-    println(reduced)
+    gauss_jordan_elimination(A)
+    println(A)
 
     soln = back_substitution(A)
     println(soln)

chapters/algorithms/gaussian_elimination/gaussian_elimination.md

@@ -383,13 +383,13 @@ Here it is in code:
 
 {% method %}
 {% sample lang="jl" %}
-[import:70-98, lang:"julia"](code/julia/gaussian_elimination.jl)
+[import:70-96, lang:"julia"](code/julia/gaussian_elimination.jl)
 {% sample lang="c" %}
 This code does not exist yet in C, so here's Julia code (sorry for the inconvenience)
-[import:70-98, lang:"julia"](code/julia/gaussian_elimination.jl)
+[import:70-96, lang:"julia"](code/julia/gaussian_elimination.jl)
 {% sample lang="rs" %}
 This code does not exist yet in rust, so here's Julia code (sorry for the inconvenience)
-[import:70-98, lang:"julia"](code/julia/gaussian_elimination.jl)
+[import:70-96, lang:"julia"](code/julia/gaussian_elimination.jl)
 {% endmethod %}
 
 ## Back-substitution