app.py

import gradio as gr
import matplotlib.pyplot as plt

# Mock individual demand curves for mahi mahi tuna (price decreases as quantity increases)
individuals = ["Mary", "Bob", "Jim"]

# Define quantity points (e.g., pounds)
quantities = [1, 2, 3, 4, 5]

# Prices per unit (downward-sloping demand)
market_demand = {
    "Mary": [25, 22, 18, 15, 10],
    "Bob": [24, 21, 17, 14, 9],
    "Jim": [26, 23, 19, 16, 11]
}




# Non-market (fish diversity) WTP stays as before (quality on X-axis)
nonmarket_levels = ["Low", "Medium", "High"]
nonmarket_wtp = {
    "Mary": [10, 18, 23],
    "Bob": [12, 16, 28],
    "Jim": [10, 10, 10]
}

import matplotlib.pyplot as plt
import numpy as np

# Define quantity range (0 to 15)
quantities = np.linspace(0, 15, 100)

import gradio as gr
import matplotlib.pyplot as plt
import numpy as np

def plot_market_demand():
    quantities = np.linspace(0, 15, 100)
    mary_prices = 30 - 1.5 * quantities
    bob_prices = 25 - 1.2 * quantities
    jim_prices = 35 - 2.0 * quantities

    fig, ax = plt.subplots(figsize=(6, 4))
    ax.plot(quantities, mary_prices, label="Mary")
    ax.plot(quantities, bob_prices, label="Bob")
    ax.plot(quantities, jim_prices, label="Jim")
    ax.set_xlabel("Quantity (Q)")
    ax.set_ylabel("Price (P)")
    ax.set_title("Individual Demand Curves")
    ax.legend()
    ax.grid(True)
    ax.set_xlim(0, 15)
    ax.set_ylim(0, 40)

    return fig




def plot_nonmarket_wtp():
    fig, ax = plt.subplots()
    for name in individuals:
        ax.plot(nonmarket_levels, nonmarket_wtp[name], marker='o', label=name)
    ax.set_title("Non-Market WTP: Fish Diversity")
    ax.set_xlabel("Quality Level")
    ax.set_ylabel("WTP ($)")
    # Force axes to start at zero
    ax.set_xlim(left=0)
    ax.set_ylim(bottom=0)
    ax.legend()
    plt.tight_layout()
    return fig

def app():
    market_fig = plot_market_demand()
    nonmarket_fig = plot_nonmarket_wtp()
    return market_fig, nonmarket_fig

demo = gr.Interface(
    fn=app,
    inputs=[],
    outputs=[gr.Plot(label="Market Demand"), gr.Plot(label="Non-Market WTP")],
    title="WTP and Demand Visualization App",
    description="Shows individual demand curves for market goods (e.g., mahi mahi tuna) and WTP curves for non-market goods (e.g., fish diversity)."
)

if __name__ == "__main__":
    demo.launch()