PK_Q_density_test_RW.py

# -*- coding: utf-8 -*-
"""
Created on Tue May 14 11:07:59 2024

@author: leizhou
"""
def create_single_folder(folder_path):
    try:
        os.mkdir(folder_path)
        print(f"file '{folder_path}' create")
    except FileExistsError:
        print(f" '{folder_path}' exists")
    except Exception as e:
        print(f" '{folder_path}' wrong: {e}")



def gaussian_kernel(M, m, h_m, T, t, h_t):
    u_m = (M-m)/h_m
    u_t = (T-t)/h_t
    return stats.norm.cdf(u_m) * stats.norm.cdf(u_t)

def epanechnikov(M, m, h_m, T, t, h_t):
    u_m = (M-m)/h_m
    u_t = (T-t)/h_t
    return (3/4) * (1-u_m)**2 * (3/4) * (1-u_t)**2

def extend_polynomial(x, y):
    """
    Extend Smile, first and second derivative so that spd exists completely for large tau
    x = M_std
    y = first
    """
    polynomial_coeff=np.polyfit(x,y,2)
    xnew=np.linspace(0.8,1.2,100)
    ynew=np.poly1d(polynomial_coeff)
    
    # plt.plot(xnew,ynew(xnew),x,y,'o')
    # plt.title('interpolated smile')
    # plt.show()
    return xnew, ynew(xnew)

def smoothing_rookley(df, m, t, h_m, h_t, IV_nn, M_nn):
    
    # kernel=gaussian_kernel, 
    extend = True
    
    # Before
    # M = np.array(df.moneyness)
    # y = np.array(df.mark_iv)
    
    M = M_nn
    y = IV_nn

    # After Poly extension
    if extend:
        print('Extending Moneyness and IV in smoothing technique!')
        M, y = extend_polynomial(M, y)
     
    
    # temp ={'IV':y, 'M':M}
    # temp = pd.DataFrame(temp)
    # plt.figure(figsize=(10, 6))
    # plt.scatter(temp['M'],temp['IV'], color='r')
    # plt.show   
     
    T = [df.tau.values[0]] * len(M) #np.array(df.tau)
    n = len(M)

    X1 = np.ones(n)
    X2 = M - m
    X3 = (M-m)**2
    X4 = T-t
    X5 = (T-t)**2
    X6 = X2*X4
    X = np.array([X1, X2, X3, X4, X5, X6]).T

    # ker = kernel(M, m, h_m, T, t, h_t)
    ker = gaussian_kernel(M, m, h_m, T, t, h_t)
    W = np.diag(ker)

    XTW = np.dot(X.T, W)

    beta = np.linalg.pinv(np.dot(XTW, X)).dot(XTW).dot(y)

    return beta[0], beta[1], 2*beta[2]


def rookley_unique_tau(df, h_m):
    # gridsize is len of estimated smile
    # df = sub
    # h_m = h
    
    h_t=0.01
    gridsize=149
    kernel='epak'

    if kernel=='epak':
        kernel = epanechnikov
    elif kernel=='gauss':
        kernel = gaussian_kernel
    else:
        print('kernel not know, use epanechnikov')
        kernel = epanechnikov

    
    num = gridsize
    M_min, M_max = min(df.moneyness), max(df.moneyness)
    # M = np.linspace(M_min, M_max, gridsize)
    
   
    # M_n = np.unique(df['moneyness'])
    # IV_n = np.full(len(M_n),np.nan)

    # for i, m in enumerate(M_n):
    #     mask = df['moneyness'] == m
    #     IV_n[i] = np.mean(df['mark_iv'][mask])
        
    M_nn = np.linspace(M_min, M_max, 1001)
    IV_nn = np.full(len(M_nn) - 1, np.nan)  # Make IV_nn one element shorter

    for i in range(len(M_nn) - 1):  # Iterate only up to the second last element
        mask = (df['moneyness'] >= M_nn[i]) & (df['moneyness'] < M_nn[i + 1])
        IV_nn[i] = np.mean(df['mark_iv'][mask])

    M_nn = M_nn[:-1]    
    
    M_nn, IV_nn = M_nn[~np.isnan(IV_nn)],IV_nn[~np.isnan(IV_nn)]
    

    # temp ={'IV':IV_nn, 'M':M_nn}
    # temp = pd.DataFrame(temp)
    # plt.figure(figsize=(10, 6))
    # plt.scatter(temp['M'],temp['IV'], color='r')
    # plt.show
 
    
    # M_std_min, M_std_max = min(df.moneyness), max(df.moneyness)
    # M_std = np.linspace(M_std_min, M_std_max, num=num)
    
    # M_std_min, M_std_max = min(M_nn), max(M_nn)
    M_std_min, M_std_max = 0.8, 1.2
    M_std = np.linspace(M_std_min, M_std_max, num=num)

    # if all taus are the same
    tau_min, tau_max = min(df.tau[(df.tau > 0)]), max(df.tau) # empty sequence for tau precision = 3
    tau = np.linspace(tau_min, tau_max, gridsize)

    x = zip(M_std, tau)
    sig = np.zeros((num, 3)) # fill
    

    # TODO: speed up with tensor instead of loop
    # (m, t) here means (M_std and tau) in x
    for i, (m, t) in enumerate(x):
        sig[i] = smoothing_rookley(df, m, t, h_m, h_t, IV_nn, M_nn)
  
    
    smile = sig[:, 0]
    first = sig[:, 1] #/ np.std(df.moneyness)
    second = sig[:, 2] #/ np.std(df.moneyness)

    # S_min, S_max = min(df.index_price), max(df.index_price)
    # K_min, K_max = min(df.strike), max(df.strike)
    # S = np.linspace(S_min, S_max, gridsize)
    # K = np.linspace(K_min, K_max, gridsize)
    S = [df['index_price'].mean() for _ in range(len(M_std))]
    K = S / M_std

    return smile, first, second, S, K, M_std, tau   

def compute_spd(sigma, sigma1, sigma2, tau, s, m2, r_const):
    
    # tau = newtau
    # s = S
    # m2 = M_std

    # SPDBL
    # Scalars
    #tau = np.mean(tau)
    #s = np.mean(s)
    r = r_const * len(s)
    #r = np.mean(r)
    #r = 0

    # now start spdbl estimation
    st = np.sqrt(tau)
    ert = np.exp(r * tau)
    rt = r * tau
    # error should be here in the length of m
    d1 = (np.log(m2) + tau * (r + 0.5 * (sigma ** 2))) / (sigma * st)
    d2 = d1 - (sigma * st)
    f = stats.norm.cdf(d1, 0, 1) - (stats.norm.cdf(d2, 0, 1)/(ert * m2))

    # First derivative of d1
    d11 = (1/(m2*sigma*st)) - (1/(st*(sigma**2))) * ((np.log(m2) + tau * r) * sigma1) + 0.5 * st * sigma1
    
    # First derivative of d2 term
    d21 = d11 - (st * sigma1)
    
    # Second derivative of d1 term
    d12 = -(1/(st * (m2**2) * sigma)) - sigma1/(st * m2 * (sigma**2)) + sigma2 * (0.5 * st - (np.log(m2) + rt)) / (st * sigma**2) + sigma1 * (2 * sigma1 * (np.log(m2) + rt)) / (st * sigma**3) - 1/(st * m2 * sigma**2)

    # Second derivative of d2 term
    d22 = d12 - (st * sigma2)

    f1 = (stats.norm.pdf(d1, 0, 1) * d11) + (1/ert) * ((-stats.norm.pdf(d2, 0, 1) * d21)/m2 + stats.norm.cdf(d2, 0, 1) / m2**2)
    
    # f2 = dnorm(d1, mean = 0, sd = 1) * d12 - d1 * dnorm(d1, mean = 0, sd = 1) * (d11^2) - (1/(ert * m) * dnorm(d2, mean = 0, sd = 1) * d22) + ((dnorm(d2, mean = 0, sd = 1) * d21)/(ert * m^2)) + (1/(ert * m) * d2 * dnorm(d2, mean = 0, sd = 1) * (d21^2)) - (2 * pnorm(d2, mean = 0, sd = 1)/(ert * (m^3))) + (1/(ert * (m^2)) * dnorm(d2, mean = 0, sd = 1) * d21)
    f2 = stats.norm.pdf(d1, 0, 1) * d12 - d1 * stats.norm.pdf(d1, 0, 1) * d11**2     - (1/(ert * m2) * stats.norm.pdf(d2, 0, 1) * d22) + ((stats.norm.pdf(d2, 0, 1)*d21)/(ert * m2**2))      + (1/(ert * m2) * d2 * stats.norm.pdf(d2, 0, 1)) * d21**2 -(2 * stats.norm.cdf(d2, 0, 1)/(ert * m2**3))     + (1/(ert * m2**2)) * stats.norm.pdf(d2, 0, 1) *d21
   
    # recover strike price
    x = s/m2
    c1 = -(m2**2) * f1
    c2 = s * (1/x**2) * ((m2**2) * f2 + 2 * m2 * f1)

    # Calculate the quantities of interest
    cdf = ert * c1 + 1
    fstar = ert * c2
    delta = f + s + f1/x
    gamma = 2 * f1 / x + s * f2 / (x**2)
    #print('\ndelta: ', delta, '\ngamma:', gamma)

    #plt.plot(fstar)
    #plt.show()

    spd = pd.DataFrame({'x': np.mean(s)/m2, # strike
                        'y': fstar, # Q density
                        'm': m2}) # Moneyness


    return spd  


def spdbl(sub, date, tau, r_const):
    
    # spd, sub = spdbl(sub_pre, date, tau, int_rate)
    
 
    # r_const = int_rate
    """
    computes spd according to Breeden and Litzenberger 1978
    """
    # plot_ident = '2020-' + str(mindate.month) + '-' + str(mindate.day) + '-' + str(tau) + '.png'
    
    tau_file = tau
    
    # Subset
    # Only calls, tau in [0, 0.25] and fix one day (bc looking at intra day here)
    
  
        # 
        # @Todo: tau should always be > 0, else check!
    
    if sub.shape[0] == 0:
        raise(ValueError('Sub is empty'))

    del sub['date']
    #sub['tau'] = round(sub['tau'], 2)
    sub['moneyness'] = round(sub['moneyness'], 3)
    sub['index_price'] = round(sub['index_price'], 2)

    sub = sub.drop_duplicates()
    #print('Only unique transactions!')
    
    print(sub.describe())

    if sub.shape[1] > 45000:
        raise(ValueError('Sub too large'))

    # Isolate vars
    sub['mark_iv'] = sub['mark_iv']/100
    # sub['mark_iv'][(sub['mark_iv'] < 0.01)] = 0
    
    M_range =  np.arange(sub['moneyness'].min(),sub['moneyness'].max() , 0.05)
   
    nrows = 2
    ncols = ceil(len(M_range) / nrows)
    fig, axes = plt.subplots(nrows=nrows, ncols=ncols, figsize=(10, 6 * nrows))
    
    # 将axes转换为1D数组，方便迭代
    axes = axes.flatten()
    
    # 记录有效子图数量
    num_plots = 0
    
    sub_keep = pd.DataFrame()
    Sum_IV = pd.DataFrame()
    for i, M_t in enumerate(M_range):
        Scale = sub[(sub['moneyness'] >= M_t) & (sub['moneyness'] < M_t + 0.05)]
        if Scale.empty:
            continue  # 如果数据为空，跳过这个循环
            
        mean_iv = Scale['mark_iv'].mean()
        mean_M = Scale['moneyness'].mean()
       
        lower_quantile = Scale['mark_iv'].quantile(0.03)
        median_quantile = Scale['mark_iv'].quantile(0.5)
        upper_quantile = Scale['mark_iv'].quantile(0.97)
    
        sns.boxplot(y='mark_iv', data=Scale, ax=axes[num_plots])
        axes[num_plots].set_ylabel('Values')
        num_observations = len(Scale)
        
        out = pd.DataFrame({
                'M_start':[Scale['moneyness'].min()],
                'M_end':[Scale['moneyness'].max()],
               'mean_M': [mean_M], 
               'obs': [num_observations], 
               'mean_iv': [mean_iv], 
               'sd_IV': [Scale['mark_iv'].std()], 
               'min_IV': [Scale['mark_iv'].min()], 
               'max_IV': [Scale['mark_iv'].max()]
               })
       
        Sum_IV =  pd.concat([Sum_IV,out])
        
        
        axes[num_plots].set_title(f'Moneyness {round(M_t, 3)} to {round(M_t + 0.05, 3)}\nN={num_observations}')
    
        # 添加分位线
        axes[num_plots].axhline(y=lower_quantile, color='r', linestyle='--', label='3rd Percentile')
        axes[num_plots].axhline(y=median_quantile, color='g', linestyle='--', label='Median (50th Percentile)')
        axes[num_plots].axhline(y=upper_quantile, color='b', linestyle='--', label='97th Percentile')
        
        Scale_keep = Scale[(Scale['mark_iv']<upper_quantile) & (Scale['mark_iv']>lower_quantile)]
        
        if Scale_keep.empty == 0:
            sub_keep = pd.concat([sub_keep,Scale_keep])
        
        num_plots += 1
    
    # 删除未使用的子图
    for j in range(num_plots, len(axes)):
        fig.delaxes(axes[j])
    
    plt.tight_layout()
    
    # 保存图形
    plt.savefig(path+'/Box_plot/Crypto_option/Box_'+np.datetime_as_string(date)[:10]+'_tau_'+str(int(tau_file))+'.png', transparent=True)
    
    # 显示图形
    plt.show()
    plt.close()
    
  
    
    temp ={'IV':sub['mark_iv'], 'M':sub['moneyness']}
    temp = pd.DataFrame(temp)
    plt.figure(figsize=(10, 6))
    plt.scatter(temp['M'],temp['IV'], color='r')
    plt.show
    plt.close()
    
    output_filename =  path+'/Box_plot/Crypto_summary/IV_'+np.datetime_as_string(date)[:10]+'_tau_'+str(int(tau_file))+'.csv'
    Sum_IV.to_csv(output_filename, index=False)
   
    
    # omit strange IV
    # sub = sub[(sub['mark_iv'] > lower_quantile) & (sub['mark_iv'] < upper_quantile)]
    sub = sub_keep
   
    
    if (sub.shape[0] == 0) | (np.unique(sub['moneyness']).shape[0] < 5):
        spd = 0
        return spd,sub
    else:
        
        h = sub.shape[0] ** (-1 / 9)
    
        # vola = sub['mark_iv'].astype(float)/100
        tau = sub['tau'].astype(float)
        #m = float(sub['index_price']/sub['strike'] # Spot price corrected for div divided by k ((s-d)/k); 
        #moneyness of an option; div always 0 here
        r = sub['interest_rate'].astype(float)
        s = sub['index_price'].astype(float)
        k = sub['strike'].astype(float)
        m = s / k
        div = 0
    
        
        # Forward price
        F = s * np.exp((r-div) * tau)
        K = m * F # k capital
        newm =(s * np.exp(-div*tau))/K
    
        sigma = []
        sigma1 = []
        sigma2 = []
    
        
        print('Choosing Bandwidth h: ', h)
        
        sigma, sigma1, sigma2, S, K, M_std, newtau = rookley_unique_tau(sub, h) # rookley(sub, h) 
    
        # save data
        temp ={'sigma':sigma, 'sigma1':sigma1, 'sigma2':sigma2,'S': S, 'K':K, 'M_std':M_std, 'newtau':newtau}
        temp = pd.DataFrame(temp)
        plt.figure(figsize=(10, 6))
        plt.scatter(temp['M_std'],temp['sigma'], color='r')
        plt.show
        
        plt.savefig(path+'Rookley_IV/'+np.datetime_as_string(date)[:10]+'_tau_'+str(int(tau_file))+'.png', transparent=True) 
        plt.close('all')  
        # sub2 = sub[(sub['mark_iv']>0.5) & (sub['mark_iv']<0.8)]
        # plt.scatter(sub2['moneyness'],sub2['mark_iv'], color='r')
        
        
        # tau is too long here!!
        spd = compute_spd(sigma, sigma1, sigma2, newtau,  S, M_std, r_const)
        
        plt.figure(figsize=(10, 6))
        plt.scatter(spd['m'],spd['y'], color='r')
        plt.show
        
        
        # kde = gaussian_kde(spd['m'], weights=spd['y'])
        # M_kde = np.linspace(max(spd['m']), 1.2, 100)
        # Q_kde = kde(M_kde)
        
        # degree = 4
        # coefficients = np.polyfit(spd['m'], spd['y'], degree)
        # polynomial = np.poly1d(coefficients)

        # M_fit = np.linspace(max(spd['m']), 1.2, 1001)
        # Q_fit = polynomial(M_fit)
        
        # # 生成拟合曲线的值
  
        # # 补充1.05到1.2区间的数据
        # M_combined = np.concatenate((spd['m'], M_fit))
        # Q_combined = np.concatenate((spd['y'], Q_fit))

        # plt.figure(figsize=(10, 6))
        # plt.scatter(M_combined,Q_combined, color='r')
        # plt.show
    
    return spd, sub


# main body

import os
import pandas as pd
# import datetime
# import statsmodels.api as sm
# import matplotlib.pyplot as plt
import numpy as np 
# import time
# import sys
# import pdb
# import pickle
# import gc
# import csv
from scipy import stats
import matplotlib.pyplot as plt
from scipy.stats import gaussian_kde
import seaborn as sns
import matplotlib.pyplot as plt
from math import ceil

# path = '/Users/tracy/Library/CloudStorage/OneDrive-NationalUniversityofSingapore/PAPER/Pricing/code/test/'
path = "/Users/ruting/Library/Mobile Documents/com~apple~CloudDocs/PK_BTC/code_data/main_code/"
os.chdir(path)

create_single_folder(path+'Rookley_IV')
file = 'final_btc_option_2021-01-01-2022-03-31.csv'
# file = 'final_btc_option_2021-04-01-2021-06-30.csv'
# file = 'final_btc_option_2021-07-01-2021-09-29.csv'
# file = 'final_btc_option_2021-10-01-2021-12-30.csv'
# file = 'final_btc_option_2022-07-01-2022-09-29.csv'
# file = 'final_btc_option_2022-10-01-2022-12-30.csv'
filename = os.path.join( path,'BRC_final/', file)
data_option = pd.read_csv(filename)

df = data_option.rename(columns={
    'indexprice': 'index_price',
    'strike_price': 'strike',
    'iv': 'mark_iv',
    'option_type': 'is_call',
    })
df['date'] = pd.to_datetime(df['date'])
df['is_call'] = np.where(df['is_call'] == 'C', 1, 0)

# Unique dates and tau values
unique_dates = df['date'].unique()
unique_taus = df['tau'].unique()  # Assuming 'tau' column exists in df

int_rate = 0

# keep_date = ["2022-11-17","2022-10-29","2022-07-22","2022-08-31"]
# filtered_df = df[df['date'].isin(pd.to_datetime(keep_date))]
# filtered_df.to_csv("CryptoRaw_data_2.csv", index=False)


# Create output directory
output_dir = 'Q_density_files_new'
os.makedirs(output_dir, exist_ok=True)


#######################################################
#
# Step 1: generating the Q density (original)
#
#######################################################

# Loop through each date and tau
start_date = np.datetime64('2021-03-29')
end_date = np.datetime64('2021-03-31')

unique_dates = unique_dates[(unique_dates>start_date) & (unique_dates<end_date)]
unique_dates = np.sort(unique_dates)
unique_taus = np.sort(unique_taus)

# date = np.datetime64('2022-09-08')

for date in unique_dates:
    sub_pre = df[(df['is_call'] == 1) & 
              (df['date'] == date) & 
               (df['moneyness'] >= 0.8) & (df['moneyness'] < 1.2) &
               (df['mark_iv'] > 0)]
       
    unique_taus_sub = sub_pre['tau'].unique()
    unique_taus_sub = np.sort(unique_taus_sub)
    date_str = np.datetime_as_string(date)[:10]
    
    for tau in unique_taus_sub:
        print(f"Processing date {date_str} and tau {tau}...")
        sub = sub_pre[(sub_pre['tau'] == tau)]
        if max(sub['moneyness']) > 1.10 and min(sub['moneyness']) < 0.85:
      
            try:
                # spd, sub = spdbl(df, date, tau, int_rate)
                spd, sub = spdbl(sub, date, tau, int_rate)
            except ValueError as e:
                print(f"Skipping date {date_str} and tau {tau} due to error: {e}")
                continue
            
            # Format date and tau for filename
            # date_str = date.strftime('%Y%m%d')
           
            # tau_str = str(tau).zfill(3)  # Zero-fill tau to 3 digits if necessary
            tau_str = str(tau)
            if isinstance(spd, int):
                print('no result')
            else:
                output_filename = os.path.join(output_dir, f'raw_Q_density_{date_str}_tau{tau_str}.csv')
                spd.to_csv(output_filename, index=False)



# # one example
# date = pd.to_datetime('2018-09-01')
# tau = 27
# int_rate = 0
# spd, sub  = spdbl(df, date, tau, int_rate)
# output_filename = 'Q_density_20180901.csv'
# spd.to_csv(output_filename, index=False)

# print(spd)
# spd.head()
# spd['y'].describe()

#######################################################
#
# Step 2: generating the Q density (tail fitting)
#
#######################################################

import pandas as pd
import numpy as np
from scipy.interpolate import splev, splrep
from scipy.stats import genextreme as gev

# path = '/Users/tracy/Library/CloudStorage/OneDrive-NationalUniversityofSingapore/PAPER/Pricing/code/test/'
path = "C:/Users/leizhou/OneDrive - National University of Singapore/PAPER/Pricing/code/test/"
os.chdir(path)



# Define the Q_tail_logret_Figlewski function
def Q_tail_logret_Figlewski(spdy, m):
    # data filtering
    spdy = spdy[(m > 0.5) & (m <= 2)]
    m = m[(m > 0.5) & (m <= 2)]

    # Check monotonicity and filter data, Find the maximum spdy
    i = np.argmax(spdy)
    spdy1 = spdy[:i+1]
    spdy2 = spdy[i:]
    m1 = m[:i+1]
    m2 = m[i:]
    a1 = np.diff(spdy1)
    a2 = np.diff(spdy2)

    # get the final spdy and m
    spdy = np.concatenate((spdy1[np.concatenate(([True], a1 > 0))], spdy2[np.concatenate((a2 < 0, [True]))]))
    m = np.concatenate((m1[np.concatenate(([True], a1 > 0))], m2[np.concatenate((a2 < 0, [True]))]))
    
    r_t = np.log(m)
    q_rt = spdy * m

    def fit_tail(target, r_t, q_rt):
        k = min(3, len(r_t) - 1)  # Ensure k is less than the number of data points
        rnd = splev(target, splrep(r_t, q_rt, k=k))
        bounds = [(-0.1, 0.5), (0.01, 0.25), (-0.5, 0.5)]

        def fitness_function(x):
            return sum([
                abs(gev.pdf(target[0], x[0], loc=x[2], scale=x[1]) - rnd[0]),
                abs(gev.pdf(target[1], x[0], loc=x[2], scale=x[1]) - rnd[1]),
                abs(gev.pdf(target[2], x[0], loc=x[2], scale=x[1]) - rnd[2])
            ])

        result = differential_evolution(fitness_function, bounds)
        return result.x

    if np.max(m) <= 1.2:
        target_r = [0.18, 0.19, 0.2]
    elif np.max(m) <= 2:
        target_r = [np.log(np.max(m)) - 0.02, np.log(np.max(m)) - 0.01, np.log(np.max(m))]
    else:
        target_r = [0.98, 0.99, 1]

    solution_r = fit_tail(target_r, r_t, q_rt)

    if np.min(m) >= 0.8:
        target_l = [-0.22, -0.21, -0.2]
    elif np.min(m) >= 0:
        target_l = [np.log(np.min(m)), np.log(np.min(m)) + 0.01, np.log(np.min(m)) + 0.02]
    else:
        raise ValueError("Minimal moneyness is negative.")

    solution_l = fit_tail(target_l, r_t, q_rt)

    return_range = np.linspace(-1, 1, 200)
    q_r = gev.pdf(np.linspace(r_t[-1] + 0.001, max(return_range), 100), solution_r[0], loc=solution_r[2], scale=solution_r[1])
    q_l = gev.pdf(np.linspace(-min(return_range), -r_t[0] + 0.001, 100), solution_l[0], loc=solution_l[2], scale=solution_l[1])

    rt = np.concatenate((np.linspace(min(return_range), r_t[0] - 0.001, 100), r_t, np.linspace(r_t[-1] + 0.001, max(return_range), 100)))
    Q_rt = np.concatenate((q_l, q_rt, q_r))

    return rt, Q_rt


# List all files in the folder
folder_path = folder_path = os.path.join(path, "Q_density_files/")
files = os.listdir(folder_path)
output_files = [file for file in files if file.startswith('raw_Q')]


# Loop through each file in the folder
for file in output_files:
    input_filename = os.path.join(folder_path, file)
    data = pd.read_csv(input_filename)

    # Extract spdy and m columns
    spdy = data['y'].values
    m = data['m'].values

    # Call the function to process data
    rt, Q_rt = Q_tail_logret_Figlewski(spdy, m)

    # Write Q density to CSV
    output = pd.DataFrame({'Return': rt, 'Q_density': Q_rt})
    
    # Create output filename by removing 'raw_' from the input filename
    output_filename = file.replace('raw_', '')
    output_path = os.path.join(folder_path, output_filename)
    output.to_csv(output_path, index=False)
    print(f"Processed and saved: {output_filename}")



from tqdm import tqdm
import numpy as np
from scipy.optimize import differential_evolution

# Loop through each file in the folder with progress bar
for i, file in enumerate(tqdm(output_files, desc="Processing files", unit="file")):
    input_filename = os.path.join(folder_path, file)
    data = pd.read_csv(input_filename)

    # Extract spdy and m columns
    spdy = data['y'].values
    m = data['m'].values

    # Call the function to process data
    rt, Q_rt = Q_tail_logret_Figlewski(spdy, m)

    # Write Q density to CSV
    output = pd.DataFrame({'Return': rt, 'Q_density': Q_rt})
    
    # Create output filename by removing 'raw_' from the input filename
    output_filename = file.replace('raw_', '')
    output_path = os.path.join(folder_path, output_filename)
    output.to_csv(output_path, index=False)

    print(f"Processed and saved: {output_filename}")