Julia constructs diagonal matrix

Be careful ,julia There is no diag function , If you want to define 4*4 Diagonal matrix of , You can use the following methods ：

1. Use Matrix function

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        using LinearAlgebra
        
  Matrix{Float64}(I,4,4)
       
       

        
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Be careful ,Matrix{Float64}(I,4,4) There are letters in the middle I, Not Numbers 1

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        julia> using LinearAlgebra
        

        
julia> Matrix{Float64}(I,4,4)
        
4×4 Array{Float64,2}:
        
 1.0  0.0  0.0  0.0
        
 0.0  1.0  0.0  0.0
        
 0.0  0.0  1.0  0.0
        
 0.0  0.0  0.0  1.0
       
       

        
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2. establish zeros matrix

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        b2 = zeros(4,4)
        
b2
       
       

        
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adopt for The diagonal of the loop is 1

Get it done .