code refactor

Author: HalemoGPA

src/main.py

@@ -22,7 +22,7 @@
 
 class FunctionPlotter(QMainWindow):
     """
-    A class representing the main window for the function plotter application.
+    Main window for the function plotter application.
 
     This class handles the GUI elements, user inputs, and plotting of mathematical functions
     using PySide2 for the GUI and Matplotlib for plotting.
@@ -33,100 +33,75 @@ class FunctionPlotter(QMainWindow):
     def __init__(self):
         super().__init__()
         self.setWindowTitle("Function Plotter")
+        self.setup_ui()
 
-        # Initialize the central widget and main layout
+    def setup_ui(self):
+        """Set up the user interface elements."""
         self.central_widget = QWidget()
         self.setCentralWidget(self.central_widget)
         self.layout = QVBoxLayout()
-        self.input_layout = QHBoxLayout()
         self.central_widget.setLayout(self.layout)
 
-        # Initialize input fields for the function and range values
-        self.function_input = QLineEdit()
-        self.function_input.setPlaceholderText("Enter function of x, e.g., 5*x^3 + 2*x")
-        self.input_layout.addWidget(self.function_input)
+        self.input_layout = QHBoxLayout()
+        self.function_input = self.create_line_edit(
+            "Enter function of x, e.g., 5*x^3 + 2*x"
+        )
+        self.min_input = self.create_line_edit("Enter min value of x")
+        self.max_input = self.create_line_edit("Enter max value of x")
 
-        self.min_input = QLineEdit()
-        self.min_input.setPlaceholderText("Enter min value of x")
+        self.input_layout.addWidget(self.function_input)
         self.input_layout.addWidget(self.min_input)
-
-        self.max_input = QLineEdit()
-        self.max_input.setPlaceholderText("Enter max value of x")
         self.input_layout.addWidget(self.max_input)
-
         self.layout.addLayout(self.input_layout)
 
-        # Initialize the plot button
         self.plot_button = QPushButton("Plot Function")
         self.plot_button.clicked.connect(self.plot_function)
         self.layout.addWidget(self.plot_button)
 
-        # Initialize the Matplotlib figure and canvas
         self.figure, self.ax = plt.subplots()
         self.canvas = FigureCanvas(self.figure)
         self.layout.addWidget(self.canvas)
 
-    def plot_function(self):
-        """
-        Handles the plotting of the function based on user inputs.
+    def create_line_edit(self, placeholder):
         """
-        function = self.function_input.text().replace(" ", "")
-        min_x = self.min_input.text()
-        max_x = self.max_input.text()
+        Create a QLineEdit with a placeholder text.
 
-        # Validate inputs
-        if not self.validate_inputs(function, min_x, max_x):
-            return
-
-        try:
-            min_x = float(min_x)
-            # Make range from -1e20 to 1e20 whatever the input
-            min_x = max(min(1e20, min_x), -1e20)
-            max_x = float(max_x)
-            # Make range from -1e20 to 1e20 whatever the input
-            max_x = max(min(1e20, max_x), -1e20)
-
-        except ValueError:
-            self.show_error_message("Min and Max values must be numbers.")
-            return
+        Parameters:
+        - placeholder (str): The placeholder text for the QLineEdit.
 
-        if min_x >= max_x:
-            self.show_error_message("Min value must be less than Max value.")
-            return
+        Returns:
+        - QLineEdit: The created QLineEdit object.
+        """
+        line_edit = QLineEdit()
+        line_edit.setPlaceholderText(placeholder)
+        return line_edit
 
-        if ("log10" in function or "sqrt" in function) and min_x < 0:
-            self.show_error_message(
-                "Min value must be non-negative for functions with log10 or sqrt."
-            )
-            return
+    def plot_function(self):
+        """Handle the plotting of the function based on user inputs."""
+        function = self.function_input.text().replace(" ", "")
+        min_x, max_x = self.min_input.text(), self.max_input.text()
 
-        # deal with the case of division by zero ex(x/0)
-        if "/0" in function:
-            self.show_error_message("Division by zero is not allowed.")
+        if not self.validate_inputs(function, min_x, max_x):
             return
 
+        min_x, max_x = self.parse_range(min_x, max_x)
         x = np.linspace(min_x, max_x, 400)
         if "log10" in function:
             x = np.where(
                 x == 0, 1e-15, x
             )  # Add a small value to x where x is 0 if log10 is in the function
+
         try:
             y = eval(self.prepare_function(function, x))
         except Exception as e:
             self.show_error_message(f"Error in function evaluation: {e}")
             return
 
-        # Clear previous plot and plot new function
-        self.ax.clear()
-        self.ax.plot(x, y)
-        self.ax.set_title(f"Plot of {function}")
-        self.ax.set_xlabel("x")
-        self.ax.set_ylabel("f(x)")
-        self.canvas.draw()
+        self.update_plot(x, y, function)
 
     def validate_inputs(self, function, min_x, max_x):
         """
-        Validates the user inputs for the function and range values.
+        Validate the user inputs for the function and range values.
 
         Parameters:
         - function (str): The mathematical function entered by the user.
@@ -148,11 +123,47 @@ def validate_inputs(self, function, min_x, max_x):
             self.show_error_message("Min and Max values cannot be empty.")
             return False
 
+        try:
+            min_x = float(min_x)
+            max_x = float(max_x)
+        except ValueError:
+            self.show_error_message("Min and Max values must be numbers.")
+            return False
+
+        if min_x >= max_x:
+            self.show_error_message("Min value must be less than Max value.")
+            return False
+
+        if ("log10" or "sqrt") in function and min_x < 0:
+            self.show_error_message(
+                "Min value must be non-negative for functions with log10 or sqrt."
+            )
+            return False
+
+        if "/0" in function:
+            self.show_error_message("Division by zero is not allowed.")
+            return False
+
         return True
 
+    def parse_range(self, min_x, max_x):
+        """
+        Parse and limit the range values to a valid range.
+
+        Parameters:
+        - min_x (str): The minimum value of x entered by the user.
+        - max_x (str): The maximum value of x entered by the user.
+
+        Returns:
+        - tuple: The parsed and limited range values.
+        """
+        min_x = max(min(1e20, float(min_x)), -1e20)
+        max_x = max(min(1e20, float(max_x)), -1e20)
+        return min_x, max_x
+
     def prepare_function(self, function, x):
         """
-        Prepares the function for evaluation by replacing operators with their numpy equivalents.
+        Prepare the function for evaluation by replacing operators with their numpy equivalents.
 
         Parameters:
         - function (str): The mathematical function entered by the user.
@@ -164,14 +175,30 @@ def prepare_function(self, function, x):
         function = function.replace("^", "**")
         function = function.replace("log10", "np.log10")
         function = function.replace("sqrt", "np.sqrt")
-        # if function is a constant (e.g. y=5)
+
         if "x" not in function:
             function = f"{function}*np.ones_like(x)"
         return function
 
+    def update_plot(self, x, y, function):
+        """
+        Update the plot with the new function.
+
+        Parameters:
+        - x (np.ndarray): The array of x values.
+        - y (np.ndarray): The array of y values.
+        - function (str): The mathematical function entered by the user.
+        """
+        self.ax.clear()
+        self.ax.plot(x, y)
+        self.ax.set_title(f"Plot of {function}")
+        self.ax.set_xlabel("x")
+        self.ax.set_ylabel("f(x)")
+        self.canvas.draw()
+
     def show_error_message(self, message):
         """
-        Displays an error message dialog.
+        Display an error message dialog.
 
         Parameters:
         - message (str): The error message to display.