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Book4_Ch03_Python_Codes/Streamlit_Bk4_Ch3_01.py

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+
+###############
+# Authored by Weisheng Jiang
+# Book 4  |  From Basic Arithmetic to Machine Learning
+# Published and copyrighted by Tsinghua University Press
+# Beijing, China, 2022
+###############
+
+import streamlit as st
+import plotly.graph_objects as go
+import numpy as np
+
+x1 = np.linspace(-2.5, 2.5, num=101);
+x2 = x1;
+xx1, xx2 = np.meshgrid(x1,x2)
+
+with st.sidebar:
+    
+    st.write('Note: Lp norm, p >= 1')
+    p = st.slider('p', 
+                  min_value = -20.0, 
+                  max_value = 20.,
+                  step = 0.2)
+    
+zz = ((np.abs((xx1))**p) + (np.abs((xx2))**p))**(1./p)
+
+fig_1 = go.Figure(data = 
+                go.Contour(z = zz,
+                x = x1,
+                y = x2,
+                colorscale='RdYlBu_r'))
+
+fig_1.update_layout(
+    autosize=False,
+    width=500,
+    height=500,
+    margin=dict(
+        l=50,
+        r=50,
+        b=100,
+        t=100,
+        pad = 4))
+
+fig_2 = go.Figure(
+    go.Surface(
+    x = x1,
+    y = x2,
+    z = zz,
+    colorscale='RdYlBu_r'))
+
+
+with st.expander('2D contour'):
+    st.plotly_chart(fig_1)
+
+with st.expander('3D surface'):
+    st.plotly_chart(fig_2)