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Using MATLAB code in the Engee environment

This example demonstrates how to call MATLAB functions in Engee, as well as their application and comparison with environment functions.

Building curves in Engee:

Enabling the backend method for displaying graphics:

In [ ]: 
Pkg.add(["Statistics"])
In [ ]: 
using Plots

We generate two signals:

In [ ]: 
A = sin.(range(0, 2pi, length=100)')' # синусоида
B = @. sin(A) + 0.1 * randn() # зашумлённая синусоида
C = 1:1:100;

We display two signals on the graph:

In [ ]: 
plot(C,A)
plot!(C,B)
Out[0]:

We calculate the correlation between the two signals by first connecting the library of statistical functions.:

In [ ]: 
using Statistics
engee_cor = cor(A,B)
Out[0]:
1×1 Matrix{Float64}:
 0.9852832893786444

Calling MATLAB code from Engee

From Julia, you can call any command or function MATLAB, which will return the result.

Connect the MATLAB interface:

In [ ]: 
using MATLAB

Loading signal data from Engee into the MATLAB core:

In [ ]: 
D = hcat(A,B)
A = D[:,1];
B = D[:,2];
mat"""
A = $A;
B = $B;
R = corrcoef(A,B);
"""

Calculating the correlation between two signals using the MATLAB kernel function:

In [ ]: 
matlab_cor = mat"R; R()"
Out[0]:
2×2 Matrix{Float64}:
 1.0       0.985283
 0.985283  1.0

Comparison of results and calculation of the absolute error of using methods from MATLAB and Engee:

In [ ]: 
difference = abs(engee_cor[1,1] - matlab_cor[1,2])
println("Корреляция Engee: ", engee_cor[1,1], '\n', "Корреляция Matlab: ", matlab_cor[1,2], '\n', "Абсолютная погрешность: ", difference)

Корреляция Engee: 0.9852832893786444
Корреляция Matlab: 0.9852832893786447
Абсолютная погрешность: 3.3306690738754696e-16

Calling a sinusoid with increasing frequency from MATLAB:

In [ ]: 
chirp = mat"chirp = dsp.Chirp('InitialFrequency', 0,'SamplesPerFrame', 500); chirp()"
plot(chirp)
Out[0]:

Building a magic square:

In [ ]: 
mat"magic(3)"
Out[0]:
3×3 Matrix{Float64}:
 8.0  1.0  6.0
 3.0  5.0  7.0
 4.0  9.0  2.0

The simplest arithmetic operations:

In [ ]: 
x = range(-10.0, stop=10.0, length=50)
y = range(2.0, stop=3.0, length=50)

mat"""
    $u = $x + $y
    $v = $x - $y
"""

plot(u,v)

>> >> >> 
matlab_jl_2 =

   -8.0000
   -7.5714
   -7.1429
   -6.7143
   -6.2857
   -5.8571
   -5.4286
   -5.0000
   -4.5714
   -4.1429
   -3.7143
   -3.2857
   -2.8571
   -2.4286
   -2.0000
   -1.5714
   -1.1429
   -0.7143
   -0.2857
    0.1429
    0.5714
    1.0000
    1.4286
    1.8571
    2.2857
    2.7143
    3.1429
    3.5714
    4.0000
    4.4286
    4.8571
    5.2857
    5.7143
    6.1429
    6.5714
    7.0000
    7.4286
    7.8571
    8.2857
    8.7143
    9.1429
    9.5714
   10.0000
   10.4286
   10.8571
   11.2857
   11.7143
   12.1429
   12.5714
   13.0000
Out[0]:

Calling MATLAB files from Engee

The path to the folder opened in the file manager:

In [ ]: 
mat"cd $(@__DIR__)"

Running the m script:

image.png
In [ ]: 
mat"file"

>> >> >> a = 10
In [ ]: 
mat"run('file.m')"

>> >> >> a = 10
In [ ]: 
mat"""run("file.m")"""

>> >> >> a = 10

Launching MATLAB-functions:

image.png
In [ ]: 
mat"fun(10,9)"
Out[0]:
103.11111111111111
In [ ]: 
x = 12;
y = 13.12;

z = mat"fun($x,$y)"

z/10
Out[0]:
17.0

Viewing the workspace MATLAB:

In [ ]: 
mat"whos"

>> >> >>   Name                     Size            Bytes  Class        Attributes

  A                      100x1               800  double                 
  B                      100x1               800  double                 
  R                        2x2                32  double                 
  a                        1x1                 8  double                 
  chirp                    1x1                 8  dsp.Chirp              
  matlab_jl_has_ans        1x1                 8  double

Cleaning up the workspace MATLAB:

In [ ]: 
mat"clear"
mat"whos"

>> >> >>   Name                   Size            Bytes  Class     Attributes

  matlab_jl_has_ans      1x1                 8  double

Conclusion:

This example demonstrates the use of MATLAB functions in the Engee environment, their joint use, as well as the numerical difference between the methods used.