![\"\u5206\u6bb5\u51fd\u6570\u5982\u4f55\u7528python\u8868\u793a\"](\"https:\/\/cdn-kb.worktile.com\/kb\/wp-content\/uploads\/2024\/04\/25200914\/d812759e-a260-473b-a5d4-f923cff06f8c.webp\")
<\/p>\n<\/p>\n
\u5206\u6bb5\u51fd\u6570\u5728Python\u4e2d\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528 \u4f7f\u7528 if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n else:<\/p>\n return 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u5206\u6bb5\u51fd\u6570 \u9664\u4e86 <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u4e86\u5d4c\u5957\u7684\u4e09\u5143\u8fd0\u7b97\u7b26\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u867d\u7136\u8fd9\u79cd\u65b9\u6cd5\u66f4\u7b80\u6d01\uff0c\u4f46\u5bf9\u4e8e\u590d\u6742\u7684\u5206\u6bb5\u51fd\u6570\u53ef\u80fd\u4f1a\u964d\u4f4e\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u3002<\/p>\n<\/p>\n \u5bf9\u4e8e\u66f4\u590d\u6742\u7684\u5206\u6bb5\u51fd\u6570\uff0c\u53ef\u4ee5\u4f7f\u7528 def piecewise_function(x):<\/p>\n conditions = [x < 0, x == 0, x > 0]<\/p>\n functions = [-1, 0, 1]<\/p>\n return np.piecewise(x, conditions, functions)<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528 import numpy as np<\/p>\n x = np.array([0, 1, 2, 3])<\/p>\n y = np.array([0, 1, 0, -1])<\/p>\n pp = PiecewisePolynomial(x, y[:, np.newaxis])<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c SymPy\u662f\u4e00\u4e2aPython\u5e93\uff0c\u7528\u4e8e\u7b26\u53f7\u8ba1\u7b97\u3002\u5b83\u4e5f\u53ef\u4ee5\u7528\u4e8e\u5b9a\u4e49\u548c\u64cd\u4f5c\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528SymPy\u5b9a\u4e49\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n x = symbols('x')<\/p>\n piecewise_function = Piecewise((-1, x < 0), (0, x == 0), (1, x > 0))<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u4e86 \u9664\u4e86\u4e0a\u8ff0\u65b9\u6cd5\uff0c\u8fd8\u53ef\u4ee5\u901a\u8fc7\u5b9a\u4e49\u4e00\u4e2a\u7c7b\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u590d\u6742\u903b\u8f91\u548c\u72b6\u6001\u7ba1\u7406\u7684\u573a\u666f\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def __init__(self):<\/p>\n pass<\/p>\n def __call__(self, x):<\/p>\n if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n else:<\/p>\n return 1<\/p>\n piecewise_function = PiecewiseFunction()<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u5b9a\u4e49\u4e86\u4e00\u4e2a Pandas\u5e93\u4e3b\u8981\u7528\u4e8e\u6570\u636e\u5904\u7406\u548c\u5206\u6790\uff0c\u4f46\u5b83\u4e5f\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528Pandas\u5e93\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def piecewise_function(x):<\/p>\n if isinstance(x, pd.Series):<\/p>\n return pd.cut(x, bins=[-float('inf'), 0, 0, float('inf')], labels=[-1, 0, 1], include_lowest=True)<\/p>\n else:<\/p>\n if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n else:<\/p>\n return 1<\/p>\n data = pd.Series([-2, -1, 0, 1, 2])<\/p>\n piecewise_function(data)<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c \u5728\u67d0\u4e9b\u7279\u5b9a\u573a\u666f\u4e0b\uff0c\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u4e5f\u53ef\u4ee5\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def piecewise_function(x):<\/p>\n if re.match(r'^[0-9]+$', str(x)):<\/p>\n return 'positive integer'<\/p>\n elif re.match(r'^-[0-9]+$', str(x)):<\/p>\n return 'negative integer'<\/p>\n else:<\/p>\n return 'non-integer'<\/p>\n print(piecewise_function(5)) # \u8f93\u51fa: positive integer<\/p>\n print(piecewise_function(-5)) # \u8f93\u51fa: negative integer<\/p>\n print(piecewise_function(5.5))# \u8f93\u51fa: non-integer<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u5339\u914d\u4e0d\u540c\u6a21\u5f0f\u7684\u8f93\u5165\u503c\uff0c\u5e76\u8fd4\u56de\u76f8\u5e94\u7684\u7ed3\u679c\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5904\u7406\u5b57\u7b26\u4e32\u6a21\u5f0f\u5339\u914d\u7684\u573a\u666f\u3002<\/p>\n<\/p>\n \u95ed\u5305\u662f\u4e00\u79cd\u5177\u6709\u5c01\u95ed\u73af\u5883\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u95ed\u5305\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def piecewise_function(x):<\/p>\n if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n else:<\/p>\n return 1<\/p>\n return piecewise_function<\/p>\n piecewise_function = make_piecewise_function()<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u5b9a\u4e49\u4e00\u4e2a\u95ed\u5305\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5728\u95ed\u5305\u4e2d\u4fdd\u7559\u72b6\u6001\u548c\u903b\u8f91\uff0c\u975e\u5e38\u7075\u6d3b\u3002<\/p>\n<\/p>\n \u88c5\u9970\u5668\u662f\u4e00\u79cd\u7528\u4e8e\u4fee\u6539\u51fd\u6570\u884c\u4e3a\u7684\u9ad8\u7ea7\u7279\u6027\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u88c5\u9970\u5668\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def wrapper(x):<\/p>\n if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n else:<\/p>\n return 1<\/p>\n return wrapper<\/p>\n @piecewise_decorator<\/p>\n def piecewise_function(x):<\/p>\n return x<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u5b9a\u4e49\u4e00\u4e2a\u88c5\u9970\u5668 \u679a\u4e3e\u7c7b\u578b\u53ef\u4ee5\u7528\u6765\u5b9a\u4e49\u5206\u6bb5\u51fd\u6570\u7684\u4e0d\u540c\u533a\u95f4\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u679a\u4e3e\u7c7b\u578b\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n class Interval(Enum):<\/p>\n NEGATIVE = -1<\/p>\n ZERO = 0<\/p>\n POSITIVE = 1<\/p>\n def piecewise_function(x):<\/p>\n if x < 0:<\/p>\n return Interval.NEGATIVE<\/p>\n elif x == 0:<\/p>\n return Interval.ZERO<\/p>\n else:<\/p>\n return Interval.POSITIVE<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: Interval.NEGATIVE<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: Interval.ZERO<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: Interval.POSITIVE<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u679a\u4e3e\u7c7b\u578b \u751f\u6210\u5668\u662f\u4e00\u79cd\u53ef\u4ee5\u8fed\u4ee3\u7684\u5bf9\u8c61\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u751f\u6210\u5668\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n if x < 0:<\/p>\n yield -1<\/p>\n elif x == 0:<\/p>\n yield 0<\/p>\n else:<\/p>\n yield 1<\/p>\n gen = piecewise_generator(-1)<\/p>\n print(next(gen)) # \u8f93\u51fa: -1<\/p>\n gen = piecewise_generator(0)<\/p>\n print(next(gen)) # \u8f93\u51fa: 0<\/p>\n gen = piecewise_generator(1)<\/p>\n print(next(gen)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u5b9a\u4e49\u4e00\u4e2a\u751f\u6210\u5668 \u5217\u8868\u53ef\u4ee5\u7528\u6765\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u5217\u8868\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n values = [-1, 0, 1]<\/p>\n def piecewise_function(x):<\/p>\n for (start, end), value in zip(intervals, values):<\/p>\n if start <= x <= end:<\/p>\n return value<\/p>\n return None<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u5217\u8868 \u5b57\u5178\u53ef\u4ee5\u7528\u6765\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u5b57\u5178\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n (-float('inf'), 0): -1,<\/p>\n (0, 0): 0,<\/p>\n (0, float('inf')): 1<\/p>\n }<\/p>\n def piecewise_function(x):<\/p>\n for (start, end), value in intervals.items():<\/p>\n if start <= x <= end:<\/p>\n return value<\/p>\n return None<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u5b57\u5178 \u5143\u7ec4\u53ef\u4ee5\u7528\u6765\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u5143\u7ec4\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def piecewise_function(x):<\/p>\n for (start, end), value in intervals:<\/p>\n if start <= x <= end:<\/p>\n return value<\/p>\n return None<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u5143\u7ec4 \u96c6\u5408\u53ef\u4ee5\u7528\u6765\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u96c6\u5408\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n (-float('inf'), 0): -1,<\/p>\n (0, 0): 0,<\/p>\n (0, float('inf')): 1<\/p>\n }<\/p>\n def piecewise_function(x):<\/p>\n for (start, end), value in intervals.items():<\/p>\n if start <= x <= end:<\/p>\n return value<\/p>\n return None<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u4f7f\u7528\u96c6\u5408 \u5d4c\u5957\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u5d4c\u5957\u51fd\u6570\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n def negative():<\/p>\n return -1<\/p>\n def zero():<\/p>\n return 0<\/p>\n def positive():<\/p>\n return 1<\/p>\n if x < 0:<\/p>\n return negative()<\/p>\n elif x == 0:<\/p>\n return zero()<\/p>\n else:<\/p>\n return positive()<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u5b9a\u4e49\u5d4c\u5957\u51fd\u6570 \u9012\u5f52\u662f\u4e00\u79cd\u51fd\u6570\u8c03\u7528\u81ea\u8eab\u7684\u7f16\u7a0b\u6280\u5de7\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u9012\u5f52\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n if x < 0:<\/p>\n return -1<\/p>\n elif x == 0:<\/p>\n return 0<\/p>\n elif x > 0:<\/p>\n return 1<\/p>\n else:<\/p>\n return piecewise_function(x)<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u9012\u5f52\u8c03\u7528 \u5217\u8868\u63a8\u5bfc\u5f0f\u662f\u4e00\u79cd\u7b80\u6d01\u7684\u6784\u9020\u5217\u8868\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n return [-1 if x < 0 else (0 if x == 0 else 1)][0]<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u5217\u8868\u63a8\u5bfc\u5f0f\u6784\u9020\u4e00\u4e2a\u5305\u542b\u5206\u6bb5\u51fd\u6570\u7ed3\u679c\u7684\u5217\u8868\uff0c\u5e76\u8fd4\u56de\u5217\u8868\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u6d01\u4e14\u6613\u4e8e\u7406\u89e3\u3002<\/p>\n<\/p>\n \u751f\u6210\u5668\u8868\u8fbe\u5f0f\u662f\u4e00\u79cd\u7b80\u6d01\u7684\u6784\u9020\u751f\u6210\u5668\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u751f\u6210\u5668\u8868\u8fbe\u5f0f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n return next((value for (start, end), value in intervals.items() if start <= x <= end), None)<\/p>\n intervals = {<\/p>\n (-float('inf'), 0): -1,<\/p>\n (0, 0): 0,<\/p>\n (0, float('inf')): 1<\/p>\n }<\/p>\n print(piecewise_function(-1)) # \u8f93\u51fa: -1<\/p>\n print(piecewise_function(0)) # \u8f93\u51fa: 0<\/p>\n print(piecewise_function(1)) # \u8f93\u51fa: 1<\/p>\n <\/code><\/pre>\n<\/p>\n \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u901a\u8fc7\u751f\u6210\u5668\u8868\u8fbe\u5f0f\u6784\u9020\u4e00\u4e2a\u751f\u6210\u5668\uff0c\u5e76\u8fd4\u56de\u751f\u6210\u5668\u7684<\/p>\n<\/p>\n \u5206\u6bb5\u51fd\u6570\u5728Python\u4e2d\u5982\u4f55\u5b9e\u73b0\uff1f<\/strong> \u5728Python\u4e2d\uff0c\u5206\u6bb5\u51fd\u6570\u53ef\u4ee5\u5904\u7406\u54ea\u4e9b\u7c7b\u578b\u7684\u6570\u636e\uff1f<\/strong> \u6709\u6ca1\u6709\u73b0\u6210\u7684\u5e93\u53ef\u4ee5\u7b80\u5316\u5206\u6bb5\u51fd\u6570\u7684\u5b9e\u73b0\uff1f<\/strong>if<\/code>\u3001elif<\/code>\u548celse<\/code>\u8bed\u53e5\u3001lambda<\/code>\u51fd\u6570\u3001numpy<\/code>\u5e93\u3001scipy<\/code>\u5e93\u7b49\u591a\u79cd\u65b9\u5f0f\u6765\u8868\u793a\u3002<\/strong>\u4e0b\u9762\u6211\u4eec\u8be6\u7ec6\u63cf\u8ff0\u5176\u4e2d\u4e00\u79cd\u65b9\u5f0f\uff1a\u901a\u8fc7if<\/code>\u3001elif<\/code>\u548celse<\/code>\u8bed\u53e5\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002<\/p>\n<\/p>\n\u4e00\u3001IF\u3001ELIF\u3001ELSE \u8bed\u53e5\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
if<\/code>\u3001elif<\/code>\u548celse<\/code>\u8bed\u53e5\u662f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u6700\u76f4\u63a5\u65b9\u5f0f\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\uff0c\u5c55\u793a\u5982\u4f55\u7528\u8fd9\u4e9b\u63a7\u5236\u6d41\u8bed\u53e5\u5b9e\u73b0\u4e00\u4e2a\u5206\u6bb5\u51fd\u6570\uff1a<\/p>\n<\/p>\ndef piecewise_function(x):<\/p>\npiecewise_function<\/code>\u6839\u636e\u8f93\u5165\u503cx<\/code>\u7684\u4e0d\u540c\u533a\u95f4\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c\u3002\u8fd9\u79cd\u65b9\u6cd5\u76f4\u89c2\u4e14\u6613\u4e8e\u7406\u89e3\uff0c\u9002\u7528\u4e8e\u7b80\u5355\u7684\u5206\u6bb5\u51fd\u6570\u3002<\/p>\n<\/p>\n\u4e8c\u3001LAMBDA \u51fd\u6570\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
if<\/code>\u3001elif<\/code>\u548celse<\/code>\u8bed\u53e5\uff0c\u8fd8\u53ef\u4ee5\u4f7f\u7528lambda<\/code>\u51fd\u6570\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002lambda<\/code>\u51fd\u6570\u662f\u4e00\u79cd\u533f\u540d\u51fd\u6570\uff0c\u9002\u7528\u4e8e\u5b9a\u4e49\u7b80\u5355\u7684\u3001\u4e34\u65f6\u7684\u51fd\u6570\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528lambda<\/code>\u51fd\u6570\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\npiecewise_function = lambda x: -1 if x < 0 else (0 if x == 0 else 1)<\/p>\n\u4e09\u3001NUMPY \u5e93\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
numpy<\/code>\u5e93\u4e2d\u7684numpy.piecewise<\/code>\u51fd\u6570\u3002numpy.piecewise<\/code>\u5141\u8bb8\u6211\u4eec\u5b9a\u4e49\u591a\u4e2a\u6761\u4ef6\u548c\u76f8\u5e94\u7684\u51fd\u6570\uff0c\u4ece\u800c\u5b9e\u73b0\u590d\u6742\u7684\u5206\u6bb5\u51fd\u6570\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<\/p>\nimport numpy as np<\/p>\nnumpy.piecewise<\/code>\u51fd\u6570\u5b9a\u4e49\u4e86\u4e09\u4e2a\u6761\u4ef6\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002numpy.piecewise<\/code>\u4f1a\u6839\u636e\u8f93\u5165\u503cx<\/code>\u7684\u4e0d\u540c\u533a\u95f4\uff0c\u8fd4\u56de\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u8fd9\u79cd\u65b9\u6cd5\u975e\u5e38\u7075\u6d3b\uff0c\u9002\u7528\u4e8e\u590d\u6742\u7684\u5206\u6bb5\u51fd\u6570\u3002<\/p>\n<\/p>\n\u56db\u3001SCIPY \u5e93\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
scipy<\/code>\u5e93\u4e2d\u7684scipy.interpolate.PiecewisePolynomial<\/code>\u53ef\u4ee5\u7528\u6765\u6784\u5efa\u5206\u6bb5\u591a\u9879\u5f0f\u51fd\u6570\u3002\u867d\u7136\u8fd9\u4e2a\u65b9\u6cd5\u4e3b\u8981\u7528\u4e8e\u63d2\u503c\u548c\u62df\u5408\uff0c\u4f46\u4e5f\u53ef\u4ee5\u7528\u6765\u8868\u793a\u5206\u6bb5\u51fd\u6570\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\uff1a<\/p>\n<\/p>\nfrom scipy.interpolate import PiecewisePolynomial<\/p>\nx<\/code>\u548cy<\/code>\u5b9a\u4e49\u4e86\u5206\u6bb5\u591a\u9879\u5f0f\u7684\u8282\u70b9\uff0cPiecewisePolynomial<\/code>\u6784\u5efa\u4e86\u5206\u6bb5\u591a\u9879\u5f0f\u51fd\u6570\u3002\u8fd9\u4e2a\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u9ad8\u7cbe\u5ea6\u63d2\u503c\u548c\u62df\u5408\u7684\u5206\u6bb5\u51fd\u6570\u3002<\/p>\n<\/p>\n\u4e94\u3001\u4f7f\u7528SymPy\u5e93\u8868\u793a\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
from sympy import Piecewise, symbols<\/p>\nPiecewise<\/code>\u7c7b\u6765\u5b9a\u4e49\u5206\u6bb5\u51fd\u6570\u3002Piecewise<\/code>\u7c7b\u5141\u8bb8\u6211\u4eec\u5b9a\u4e49\u591a\u4e2a\u6761\u4ef6\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u4ec5\u53ef\u4ee5\u5904\u7406\u6570\u503c\uff0c\u8fd8\u53ef\u4ee5\u5904\u7406\u7b26\u53f7\u8868\u8fbe\u5f0f\uff0c\u975e\u5e38\u9002\u5408\u9700\u8981\u7b26\u53f7\u8ba1\u7b97\u7684\u573a\u666f\u3002<\/p>\n<\/p>\n\u516d\u3001\u901a\u8fc7\u81ea\u5b9a\u4e49\u7c7b\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
class PiecewiseFunction:<\/p>\nPiecewiseFunction<\/code>\u7c7b\uff0c\u5e76\u5b9e\u73b0\u4e86__call__<\/code>\u65b9\u6cd5\uff0c\u4f7f\u5f97\u5b9e\u4f8b\u5bf9\u8c61\u53ef\u4ee5\u50cf\u51fd\u6570\u4e00\u6837\u8c03\u7528\u3002\u8fd9\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5728\u7c7b\u4e2d\u6dfb\u52a0\u66f4\u591a\u7684\u903b\u8f91\u548c\u72b6\u6001\uff0c\u9002\u7528\u4e8e\u590d\u6742\u7684\u5206\u6bb5\u51fd\u6570\u3002<\/p>\n<\/p>\n\u4e03\u3001\u4f7f\u7528pandas\u5e93\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
import pandas as pd<\/p>\npd.cut<\/code>\u51fd\u6570\u88ab\u7528\u6765\u6839\u636e\u8f93\u5165\u503cx<\/code>\u7684\u4e0d\u540c\u533a\u95f4\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5904\u7406\u5927\u91cf\u6570\u636e\u7684\u573a\u666f\u3002<\/p>\n<\/p>\n\u516b\u3001\u901a\u8fc7\u6b63\u5219\u8868\u8fbe\u5f0f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
import re<\/p>\n\u4e5d\u3001\u4f7f\u7528\u95ed\u5305\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def make_piecewise_function():<\/p>\n\u5341\u3001\u4f7f\u7528\u88c5\u9970\u5668\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_decorator(func):<\/p>\npiecewise_decorator<\/code>\u6765\u4fee\u6539piecewise_function<\/code>\u51fd\u6570\u7684\u884c\u4e3a\u3002\u8fd9\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5728\u4e0d\u4fee\u6539\u539f\u59cb\u51fd\u6570\u7684\u60c5\u51b5\u4e0b\u6dfb\u52a0\u5206\u6bb5\u903b\u8f91\u3002<\/p>\n<\/p>\n\u5341\u4e00\u3001\u4f7f\u7528\u679a\u4e3e\u7c7b\u578b\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
from enum import Enum<\/p>\nInterval<\/code>\u5b9a\u4e49\u4e86\u5206\u6bb5\u51fd\u6570\u7684\u4e0d\u540c\u533a\u95f4\u3002\u679a\u4e3e\u7c7b\u578b\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n<\/p>\n\u5341\u4e8c\u3001\u4f7f\u7528\u751f\u6210\u5668\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_generator(x):<\/p>\npiecewise_generator<\/code>\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u751f\u6210\u5668\u53ef\u4ee5\u5728\u9700\u8981\u65f6\u751f\u6210\u503c\uff0c\u975e\u5e38\u9002\u5408\u5904\u7406\u5927\u6570\u636e\u548c\u6d41\u5f0f\u6570\u636e\u3002<\/p>\n<\/p>\n\u5341\u4e09\u3001\u4f7f\u7528\u5217\u8868\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
intervals = [(-float('inf'), 0), (0, 0), (0, float('inf'))]<\/p>\nintervals<\/code>\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\uff0c\u5217\u8868values<\/code>\u5b58\u50a8\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u901a\u8fc7\u904d\u5386\u533a\u95f4\u5217\u8868\u548c\u51fd\u6570\u503c\u5217\u8868\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u6d01\u4e14\u6613\u4e8e\u6269\u5c55\u3002<\/p>\n<\/p>\n\u5341\u56db\u3001\u4f7f\u7528\u5b57\u5178\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
intervals = {<\/p>\nintervals<\/code>\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u901a\u8fc7\u904d\u5386\u5b57\u5178\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u6d01\u4e14\u6613\u4e8e\u6269\u5c55\u3002<\/p>\n<\/p>\n\u5341\u4e94\u3001\u4f7f\u7528\u5143\u7ec4\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
intervals = [((-float('inf'), 0), -1), ((0, 0), 0), ((0, float('inf')), 1)]<\/p>\nintervals<\/code>\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u901a\u8fc7\u904d\u5386\u5143\u7ec4\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u6d01\u4e14\u6613\u4e8e\u6269\u5c55\u3002<\/p>\n<\/p>\n\u5341\u516d\u3001\u4f7f\u7528\u96c6\u5408\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
intervals = {<\/p>\nintervals<\/code>\u5b58\u50a8\u5206\u6bb5\u51fd\u6570\u7684\u533a\u95f4\u548c\u76f8\u5e94\u7684\u51fd\u6570\u503c\u3002\u901a\u8fc7\u904d\u5386\u96c6\u5408\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u6d01\u4e14\u6613\u4e8e\u6269\u5c55\u3002<\/p>\n<\/p>\n\u5341\u4e03\u3001\u4f7f\u7528\u5d4c\u5957\u51fd\u6570\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_function(x):<\/p>\nnegative<\/code>\u3001zero<\/code>\u548cpositive<\/code>\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u7ed3\u6784\u6e05\u6670\uff0c\u6613\u4e8e\u7ef4\u62a4\u3002<\/p>\n<\/p>\n\u5341\u516b\u3001\u4f7f\u7528\u9012\u5f52\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_function(x):<\/p>\npiecewise_function<\/code>\u51fd\u6570\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u590d\u6742\u9012\u5f52\u903b\u8f91\u7684\u573a\u666f\u3002<\/p>\n<\/p>\n\u5341\u4e5d\u3001\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_function(x):<\/p>\n\u4e8c\u5341\u3001\u4f7f\u7528\u751f\u6210\u5668\u8868\u8fbe\u5f0f\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570<\/h3>\n<\/p>\n
def piecewise_function(x):<\/p>\n\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528if-elif-else<\/code>\u7ed3\u6784\u6765\u5b9e\u73b0\u5206\u6bb5\u51fd\u6570\u3002\u9996\u5148\uff0c\u5b9a\u4e49\u4e00\u4e2a\u51fd\u6570\uff0c\u5e76\u5728\u51fd\u6570\u5185\u90e8\u6839\u636e\u4e0d\u540c\u7684\u8f93\u5165\u503c\u5e94\u7528\u4e0d\u540c\u7684\u903b\u8f91\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u901a\u8fc7\u7b80\u5355\u7684\u6761\u4ef6\u8bed\u53e5\u6765\u5224\u65ad\u8f93\u5165\u503c\u5c5e\u4e8e\u54ea\u4e2a\u533a\u95f4\uff0c\u5e76\u8fd4\u56de\u76f8\u5e94\u7684\u7ed3\u679c\u3002<\/p>\n
\u5206\u6bb5\u51fd\u6570\u53ef\u4ee5\u5904\u7406\u5404\u79cd\u7c7b\u578b\u7684\u6570\u636e\uff0c\u5305\u62ec\u6574\u6570\u3001\u6d6e\u70b9\u6570\u548c\u5b57\u7b26\u4e32\u7b49\u3002\u5177\u4f53\u53d6\u51b3\u4e8e\u4f60\u5e0c\u671b\u5728\u4e0d\u540c\u6761\u4ef6\u4e0b\u8fd4\u56de\u4ec0\u4e48\u6837\u7684\u503c\u3002\u4f8b\u5982\uff0c\u5982\u679c\u8f93\u5165\u7684\u662f\u6570\u503c\u578b\u6570\u636e\uff0c\u53ef\u4ee5\u6839\u636e\u6570\u503c\u8303\u56f4\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c\uff1b\u5982\u679c\u662f\u5b57\u7b26\u4e32\uff0c\u53ef\u4ee5\u6839\u636e\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u8fdb\u884c\u4e0d\u540c\u7684\u5904\u7406\u3002<\/p>\n
\u662f\u7684\uff0cPython\u4e2d\u6709\u4e00\u4e9b\u5e93\u53ef\u4ee5\u5e2e\u52a9\u7b80\u5316\u5206\u6bb5\u51fd\u6570\u7684\u5b9e\u73b0\u3002\u4f8b\u5982\uff0cNumPy\u5e93\u63d0\u4f9b\u4e86np.piecewise()<\/code>\u51fd\u6570\uff0c\u53ef\u4ee5\u975e\u5e38\u65b9\u4fbf\u5730\u5b9a\u4e49\u5206\u6bb5\u51fd\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u5141\u8bb8\u4f60\u4e3a\u6bcf\u4e2a\u6761\u4ef6\u6307\u5b9a\u4e00\u4e2a\u5bf9\u5e94\u7684\u51fd\u6570\u6216\u503c\uff0c\u4f7f\u5f97\u5206\u6bb5\u51fd\u6570\u7684\u5b9e\u73b0\u66f4\u52a0\u7b80\u6d01\u548c\u9ad8\u6548\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5206\u6bb5\u51fd\u6570\u5728Python\u4e2d\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528if\u3001elif\u548celse\u8bed\u53e5\u3001lambda\u51fd\u6570\u3001numpy\u5e93\u3001scipy\u5e93 […]","protected":false},"author":3,"featured_media":1159138,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1159131"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=1159131"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1159131\/revisions"}],"predecessor-version":[{"id":1159141,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1159131\/revisions\/1159141"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1159138"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1159131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1159131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1159131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}