Using julia pycall to use matplotlib pyplot inside a julia module

When working with Julia, it is often necessary to use external libraries or modules to perform specific tasks. One common requirement is to use the matplotlib pyplot library inside a Julia module. In this article, we will explore three different ways to achieve this using Julia’s pycall package.

Option 1: Using PyCall directly

The first option is to use the PyCall package directly to import and use the matplotlib pyplot library. PyCall allows Julia to call Python functions and libraries, making it a convenient option for using matplotlib in Julia.

using PyCall
@pyimport matplotlib.pyplot as plt

function plot_data(x, y)
    plt.plot(x, y)
    plt.show()
end

x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plot_data(x, y)

This code snippet demonstrates how to use PyCall to import the pyplot module and create a simple plot. The plot_data function takes two arrays, x and y, and plots them using the imported pyplot library. Finally, the plot is displayed using the plt.show() function.

Option 2: Using PyPlot package

Another option is to use the PyPlot package, which provides a higher-level interface to matplotlib specifically designed for Julia. PyPlot provides a more Julia-like syntax for creating plots and is often preferred by Julia users.

using PyPlot

function plot_data(x, y)
    plot(x, y)
    show()
end

x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plot_data(x, y)

In this code snippet, we use the PyPlot package to create the plot. The plot_data function takes the same arguments as before, but this time we use the plot and show functions directly from the PyPlot package. The resulting plot is displayed using the show() function.

Option 3: Using PyCall with a custom module

If you prefer to encapsulate the matplotlib functionality in a separate module, you can create a custom module that imports and uses the pyplot library. This approach allows for better organization and reusability of code.

using PyCall

module MyPlotModule
    @pyimport matplotlib.pyplot as plt

    export plot_data

    function plot_data(x, y)
        plt.plot(x, y)
        plt.show()
    end
end

using .MyPlotModule

x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

MyPlotModule.plot_data(x, y)

In this code snippet, we create a custom module called MyPlotModule that imports the pyplot library using PyCall. The plot_data function is defined within the module and can be accessed using the module name followed by the function name. The resulting plot is displayed using the plt.show() function.

After exploring these three options, it is clear that using the PyPlot package provides a more Julia-like syntax and is often preferred by Julia users. It offers a higher-level interface to matplotlib and allows for easier creation of plots. Therefore, Option 2: Using PyPlot package is the better option for using matplotlib pyplot inside a Julia module.