该文档是matlab编写的算法，请转译成python语言

此MATLAB脚本实现了一个名为`randomfrog_pls`的功能，主要用于高维数据中的变量选择，并且使用了随机蛙跳（Random Frog）的方法进行操作。下面是基于相同逻辑的一个Python版本示意代码：

import numpy as np
from sklearn.preprocessing import scale
from sklearn.cross_decomposition import PLSRegression
from sklearn.model_selection import cross_val_score

def pls_cross_validation(X, y, n_components, cv_folds, method):
    # Placeholder for actual implementation
    pass

def generate_new_model(current_variables, new_size, importance_scores, all_variable_indices, X, y, n_components, method, criterion):
    current_length = len(current_variables)
    difference = new_size - current_length
    
    if difference > 0:
        available_indices = np.setdiff1d(all_variable_indices, current_variables)
        
        # Select candidates and evaluate them
        selected_candidates = available_indices[np.random.choice(len(available_indices), min(3 * difference, len(available_indices)), replace=False)]
        temp_model_vars = np.concatenate((current_variables, selected_candidates))
        temp_importance = abs(getattr(pls_regression(X[:, temp_model_vars], y, n_components, method).fit(), criterion))

        # Choose top features based on scores
        sorted_scores_idx = np.argsort(temp_importance)[::-1]
        return temp_model_vars[sorted_scores_idx[:new_size]]
    
    elif difference < 0:
        # For reduction in size, just pick the highest scoring ones
        sorted_scores_idx = np.argsort(importance_scores)[::-1]
        return current_variables[sorted_scores_idx[:new_size]]

    else:
        return current_variables


def randomfrog_pls(X, y, max_latent_variables, data_preprocess_method, iterations, initial_sample_size, evaluation_criterion):
    if evaluation_criterion not in ['regcoef', 'sr']:
        evaluation_criterion = 'regcoef'
    
    if initial_sample_size < 2:
        initial_sample_size = 2
        
    num_samples, num_features = X.shape
    variable_indices = np.arange(num_features)

    if data_preprocess_method == 'autoscaling':
        X = scale(X)

    sampled_variables = np.random.choice(variable_indices, initial_sample_size, replace=False)
    models = np.zeros((iterations, num_features), dtype=bool)

    probabilities = np.zeros(num_features)
    for iteration in range(iterations):
        new_sample_size = int(round(np.random.randn() * 0.3 * len(sampled_variables)) + len(sampled_variables))
        new_sample_size = max(min(new_sample_size, num_features), 2)

        # Assuming that this function is implemented elsewhere
        regression_result = pls_regression(X[:, sampled_variables], y, max_latent_variables, data_preprocess_method)

        if evaluation_criterion == 'regcoef':
            feature_importance = abs(regression_result.coef_)
        elif evaluation_criterion == 'sr':
            feature_importance = regression_result.scores_

        proposed_variables = generate_new_model(
            sampled_variables,
            new_sample_size,
            feature_importance,
            variable_indices,
            X,
            y,
            max_latent_variables,
            data_preprocess_method,
            evaluation_criterion
        )

        # Assuming that this function is implemented elsewhere
        current_cv_score = pls_cross_validation(X[:, sampled_variables], y, max_latent_variables, 3, data_preprocess_method)
        proposed_cv_score = pls_cross_validation(X[:, proposed_variables], y, max_latent_variables, 3, data_preprocess_method)

        accept_probability = 1 if proposed_cv_score < current_cv_score else 0.1 * current_cv_score / proposed_cv_score
        should_accept = accept_probability > np.random.rand()

        if should_accept:
            sampled_variables = proposed_variables

        models[iteration, sampled_variables] = True
        probabilities[sampled_variables] += 1

        if iteration % 100 == 0:
            print(f"The {iteration}th sampling for random frog finished.")

    probabilities /= iterations
    sorted_indices = np.argsort(probabilities)[::-1]
    top_10_variables = sorted_indices[:10]

    result = {
        "iterations": iterations,
        "initial_sample_size": initial_sample_size,
        "models": models,
        "time_minutes": None,  # This would be calculated from start to finish time
        "data_preprocessing": data_preprocess_method,
        "variable_ranking": sorted_indices,
        "top_10_variables": top_10_variables,
        "probabilities": probabilities,
        "sample_sizes_per_iteration": None,  # To be filled with logic similar to MATLAB code
        "rmse_per_iteration": None  # To be filled with logic similar to MATLAB code
    }
    return result

def pls_regression(X, y, n_components, method):
    # Placeholder for actual implementation
    pass

注意：这个Python示例代码中包含了两个占位函数`pls_regression`和`pls_cross_validation`，在实际应用时需要根据具体需求来实现这两个函数。另外，在MATLAB原始代码中存在一些特定于工具箱的操作，例如`PLS.regcoef_pretreat`或`PLS.SR`等属性访问方式，这些需要替换为适合Python环境下的对应方法。此外，对于模型评估准则的选择（如'regcoef'与'sr'），也需要根据具体应用场景确定其对应的Python实现。