rate = 4.0 inter_arrival_times = rng.exponential(scale=1./rate, size=50) 接下来,我们使用 NumPy 的add通用函数的accumulate方法计算实际到达时间。我们还创建一个包含 0 到 49 的整数的数组,表示每个点的到达次数: 代码语言:javascript 代码运行次数:0 运行 复制 arrivals = np.add.accumulate(inter_arrival...
六、形态图像处理 在本章中,我们将讨论数学形态学和形态学图像处理。形态图像处理是与图像中特征的形状或形态相关的非线性操作的集合。这些操作特别适合于二值图像的处理(其中像素表示为 0 或 1,并且根据惯例,对象的前景=1 或白色,背景=0 或黑色),尽管它可以扩展到灰度图像。 在形态学运算中,使用结构元素(小模...
self.x = x self.y = ydef__repr__(self):returnf'Vector({self.x!r},{self.y!r})'def__abs__(self):returnmath.hypot(self.x, self.y)def__bool__(self):returnbool(abs(self))def__add__(self, other): x = self.x + other.x y = self.y + other.yreturnVector(x, y)def__...
要生成 0 到 1 之间的随机浮点数,包括 0 但不包括 1,我们使用rng对象上的random方法: random_floats = rng.random(size=(5,5))# array([[0.22733602, 0.31675834, 0.79736546, 0.67625467, 0.39110955],# [0.33281393, 0.59830875, 0.18673419, 0.67275604, 0.94180287],# [0.24824571, 0.94888115, 0.66723745, 0...
You can append an array with columns that are two rows high to another array with columns that are two rows high. The following example demonstrates how to add elements to a NumPy array using thenumpy.append()function: importnumpyasnp# create 2D array objects (integers)np_arr1=np.array([...
+= is faster than + for concatenating more than two strings because the first string (example, s1 for s1 += s2 + s3) is not destroyed while calculating the complete string.▶ Let's make a giant string!def add_string_with_plus(iters): s = "" for i in range(iters): s += "...
dis('s[2]+=b') # 此处 原文是s[a] 1 0 LOAD_NAME 0 (s) 2 LOAD_CONST 0 (2) 4 DUP_TOP_TWO 6 BINARY_SUBSCR① 8 LOAD_NAME 1 (b) 10 INPLACE_ADD② 12 ROT_THREE 14 STORE_SUBSCR③ 16 LOAD_CONST 1 (None) 18 RETURN_VALUE 上面是我的结果,跟书中的不太一样(这种我就不...
| This affects how floats are converted to and from binary strings. | | fromhex(string, /) from builtins.type | Create a floating-point number from a hexadecimal string. | | >>> float.fromhex('0x1.ffffp10') | 2047.984375 | >>> float.fromhex('-0x1p-1074') | -5e-324 | | --...
| one of the latter two if it appears to match the underlying C reality. | | Override the automatic determination of C-level floating point type. | This affects how floats are converted to and from binary strings. 1. 2. 3. 4.
5.0 // 3.0 # => 1.0 # works on floats too -5.0 // 3.0 # => -2.0 两个除号表示取整除,Python会为我们保留去除余数的结果。 除了取整除操作之外还有取余数操作,数学上称为取模,Python中用%表示。 # Modulo operation 7 % 3 # => 1