fitt/newly_added/formula.py

import re
def convert_log(expression):
    # 匹配log(x,b)的正则表达式
    pattern = r'log\((\w+),(\w+)\)'
    match = re.match(pattern, expression)
    if match:
        x = match.group(1)
        b = match.group(2)
        # 构造新表达式
        new_expression = f'(np.log({x}) + 1e-5) / (np.log({b}) + 1e-5)'
        return new_expression
    else:
        return None

def convert_e(expression):
    new_expression = 'np.exp'+expression[2:]
    return new_expression

def convert_trigonometric(expression):
    # 构造新表达式
    new_expression = 'np.'+expression
    return new_expression

def convert_x(expression):
    # 匹配log(x,b)的正则表达式
    pattern = r'(\w+)\^(\w+)'
    match = re.match(pattern, expression)
    if match:
        base = match.group(1)
        exponent = match.group(2)
        # 构造新表达式
        new_expression = f'np.power({base}, {exponent})'
        return new_expression
    else:
        return None
def remove_inner_spaces(expression):
    # 匹配括号内的空格的正则表达式
    pattern = r'\((.*?)\)'
    # 替换匹配到的括号内的空格
    new_expression = re.sub(pattern, lambda match: '(' + match.group(1).replace(' ', '') + ')', expression)
    return new_expression

def add_spaces(expression):
    # 匹配运算符的正则表达式
    pattern = r'([+\-*/])'
    # 替换匹配到的运算符
    new_expression = re.sub(pattern, r' \1 ', expression)
    return new_expression

def find_letter_index(string):
    pattern = r'([a-zA-Z])x\b'
    matches = re.findall(pattern, string)
    # print(matches)
    letter_indices = []
    for i in range(len(string)):
        if string[i] in matches:
            if string[i+1]=='x':
                letter_indices.append(i)
    return letter_indices

def expression_output(expression):
    # 示例使用
    modified_list = find_letter_index(expression)  # 将x前没有*的加上
    index = 1
    for i in modified_list:
        expression = expression[0:index+i]+'*'+expression[index+i:]
        index += 1
    # print(expression)
    expression = add_spaces(expression)
    new_expression = remove_inner_spaces(expression)
    list_expression = new_expression.split(' ')
    conforms = ['e^', 'log', 'sin', 'cos', 'tan', '^']
    new_list = []
    for expres in list_expression:
        new_list.append(expres)
        for i in range(6):
            if conforms[i] in expres:
                index = list_expression.index(expres)
                if i == 0:
                    list_expression[index] = convert_e(expres)
                elif i == 1:
                    list_expression[index] = convert_log(expres)
                elif i == 5:
                    list_expression[index] = convert_x(expres)
                else:
                    list_expression[index] = convert_trigonometric(expres)
                new_list[-1] = new_list[-1].replace(conforms[i], "")
                break
    new_list = [char for item in new_list for char in item if char.isalpha()]
    parameter ='x,'
    for item in new_list:
        if item not in parameter and item != 'x':
            parameter = parameter+item+','
    for item in new_list:
        if item not in parameter:
            parameter = parameter+item+','
    str_expression = ''
    for item in list_expression:
        str_expression = str_expression + item
    if len(parameter[:-1]) > 1:
        return parameter[:-1], str_expression
    else:
        return None, None