leftovers

turtle/star.py

@@ -0,0 +1,100 @@
+import tkinter as tk
+import turtle
+import math
+
+# ---------- Tk setup ----------
+root = tk.Tk()
+root.title("Turtle Function Inspector")
+
+# ---------- Canvas ----------
+canvas = tk.Canvas(root, width=600, height=600)
+canvas.grid(row=0, column=0, rowspan=6)
+
+screen = turtle.TurtleScreen(canvas)
+screen.setworldcoordinates(-300, -300, 300, 300)
+
+t = turtle.RawTurtle(screen)
+t.speed(0)
+t.hideturtle()
+
+# ---------- Globals ----------
+scale = 40  # zoom level
+
+# ---------- Drawing ----------
+def draw_axes():
+    t.clear()
+    t.color("black")
+    t.penup()
+    t.goto(-300, 0)
+    t.pendown()
+    t.goto(300, 0)
+
+    t.penup()
+    t.goto(0, -300)
+    t.pendown()
+    t.goto(0, 300)
+
+def plot_function():
+    draw_axes()
+    expr = func_entry.get()
+
+    t.color("blue")
+    t.penup()
+
+    first = True
+    for px in range(-300, 300):
+        try:
+            x = px / scale
+            y = eval(expr, {"x": x, "math": math})
+            py = y * scale
+
+            if abs(py) > 300:
+                raise ValueError
+
+            if first:
+                t.goto(px, py)
+                t.pendown()
+                first = False
+            else:
+                t.goto(px, py)
+        except:
+            t.penup()
+            first = True
+
+# ---------- Zoom ----------
+def zoom_in():
+    global scale
+    scale *= 1.25
+    plot_function()
+
+def zoom_out():
+    global scale
+    scale /= 1.25
+    plot_function()
+
+# ---------- Mouse inspection ----------
+info = tk.Label(root, text="x=0  y=0")
+info.grid(row=5, column=1)
+
+def inspect(event):
+    x = (event.x - 300) / scale
+    try:
+        y = eval(func_entry.get(), {"x": x, "math": math})
+        info.config(text=f"x={x:.3f}   y={y:.3f}")
+    except:
+        info.config(text="undefined")
+
+canvas.bind("<Motion>", inspect)
+
+# ---------- Controls ----------
+tk.Label(root, text="f(x) =").grid(row=0, column=1)
+func_entry = tk.Entry(root, width=20)
+func_entry.insert(0, "math.sin(x)")
+func_entry.grid(row=1, column=1)
+
+tk.Button(root, text="Plot", command=plot_function).grid(row=2, column=1)
+tk.Button(root, text="Zoom +", command=zoom_in).grid(row=3, column=1)
+tk.Button(root, text="Zoom -", command=zoom_out).grid(row=4, column=1)
+
+plot_function()
+root.mainloop()