From 9520ef245ca48c089e53d7237acc1719016b01d2 Mon Sep 17 00:00:00 2001
From: renerpjm5-glitch <renerpjm5@gmail.com>
Date: Sat, 3 Jan 2026 16:33:36 +0700
Subject: [PATCH] Add Bisection Method functionality to app

Implement Bisection Method for root finding in Streamlit app.
---
 streamlit_app.py | 69 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/streamlit_app.py b/streamlit_app.py
index fde12be..a52583a 100644
--- a/streamlit_app.py
+++ b/streamlit_app.py
@@ -3,4 +3,73 @@
 st.title("🎈 My new app")
 st.write(
     "Let's start building! For help and inspiration, head over to [docs.streamlit.io](https://docs.streamlit.io/)."
+    import streamlit as st
+import sympy as sp
+import pandas as pd
+
+# Judul Aplikasi
+st.title("Aplikasi Web Solusi SPNL")
+st.subheader("Metode Bisection")
+
+st.write("""
+Metode Bisection digunakan untuk mencari akar dari persamaan nonlinear 
+dengan membagi interval secara berulang hingga diperoleh solusi mendekati nol.
+""")
+
+# Input persamaan
+x = sp.symbols('x')
+fungsi_input = st.text_input("Masukkan fungsi f(x):", "x**3 - x - 2")
+
+# Input parameter
+a = st.number_input("Batas bawah (a):", value=1.0)
+b = st.number_input("Batas atas (b):", value=2.0)
+toleransi = st.number_input("Toleransi error:", value=0.0001)
+max_iter = st.number_input("Maksimum iterasi:", value=20, step=1)
+
+if st.button("Hitung Akar"):
+    try:
+        f = sp.sympify(fungsi_input)
+        f_lambdified = sp.lambdify(x, f)
+
+        fa = f_lambdified(a)
+        fb = f_lambdified(b)
+
+        if fa * fb > 0:
+            st.error("f(a) dan f(b) harus memiliki tanda yang berbeda!")
+        else:
+            data = []
+            iterasi = 1
+
+            while iterasi <= max_iter:
+                c = (a + b) / 2
+                fc = f_lambdified(c)
+
+                data.append([iterasi, a, b, c, fc])
+
+                if abs(fc) < toleransi:
+                    break
+
+                if fa * fc < 0:
+                    b = c
+                    fb = fc
+                else:
+                    a = c
+                    fa = fc
+
+                iterasi += 1
+
+            df = pd.DataFrame(
+                data,
+                columns=["Iterasi", "a", "b", "c (Akar)", "f(c)"]
+            )
+
+            st.success("Perhitungan selesai!")
+            st.write("### Tabel Iterasi Metode Bisection")
+            st.dataframe(df)
+
+            st.write(f"### Akar Hampiran = {c}")
+
+    except Exception as e:
+        st.error(f"Terjadi kesalahan: {e}")
+
 )