The provided code is not entirely correct and does not follow good coding practices. Here's a revised version of the code that addresses these issues:

Using degrees of freedom for t-student residuals in GARCH Models: A Comprehensive Guide to Estimation and Model Checking.

Using Grammatical Evolution for Symbolic Regression in R: A Practical Guide

Optimizing Exponential Distribution Parameters using Maximum Likelihood Estimation in R

How to Calculate Correlation Significance using corrplot and Spearman's Rho in R

Understanding Histograms in R: The Role of Bins and the Importance of Consistency

Understanding How to Calculate Cohen's d Using the `pwr` Package in R: A Deep Dive into the `d` Parameter

Generating Normal Random Variables from Uniform Distributions Using the Box-Muller Transform: A Single Vector Approach

Calculating Correlation and Hypothesizing Statistical Significance in Data Analysis with Python.

Rethinking Bayesian Modeling in R: A Deep Dive into Optimization Issues and Solutions