用途：給定折斷點坐標信息，插值出折線圖上對應點的y值
例如：

輸入: cut_dots=np.array([[0,0.5],[8,0.65],[18,0.996],[63,0.996]]) #need min/max

擬合結果圖

輸出: 0.5 0.519 0.538 0.556 0.575 0.594 0.612 0.631 0.65 0.685 0.719 0.754 0.788 0.823 0.858 0.892 0.927 0.961 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996 0.996

完整代碼

import numpy as np
import matplotlib.pyplot as plt

def write2txt(txt_path,write_array,type):
    with open(txt_path,'w') as f:
        for i in range(write_array.size):
            if type=='float':
                print(np.around(write_array[i],3),end=' ',file=f)
                print(np.around(write_array[i],3),end=' ')
            elif type=='int':
                print(write_array[i].astype(int),end=' ',file=f)
                print(write_array[i].astype(int),end=' ')

def line_mode(cut_dots):
    cut_dots_T = cut_dots.T
    x = cut_dots_T[0]
    y = cut_dots_T[1]
    table_x = np.linspace(x[0],x[-1],x[-1]-x[0]+1)

    for i in range(x.size-1):
        if i==0:
            table_y = np.linspace(y[0],y[1],x[1]-x[0]+1)
        else:
            table_y = np.concatenate((table_y, np.linspace(y[i],y[i+1],x[i+1]-x[i]+1)[1:]))
    plt.plot(table_x, table_y)
    plt.show()
    return(table_x,table_y)

if __name__ == '__main__':
    # 1. 定義折點，須包括第一個和最后一個點（務必確保最小和最大的x值），定義輸出值類型
    cut_dots=np.array([[0,0.5],[8,0.65],[18,0.996],[63,0.996]]) #need min/max
    type = 'float'#'int'
    # 2. 繪制多段折線圖，并返回擬合的y值
    table_x,table_y = line_mode(cut_dots)
    # 3. 輸出&輸出為txt，指定輸出文件名
    txt = r'table_y.txt'

    write2txt(txt,table_y,type)