Question

我对以下代码输出感到困惑：

import numpy as np

numStates = 4
v1 = np.zeros( numStates, dtype = float)    
v2 = np.zeros( numStates, dtype = float )
d1 = np.array([0.24, 0.16, 0.08, 0.8])
d2 = np.array([0.56, 0.64, 0.72, 0.0])
payoff = np.array( [ 0.0, 10.0, 20.0, 30.0 ] )
# to index interior point
indexVet = np.arange(1, 3, 1)

stopit = False
maxIter = 10
count = 0
while not stopit:
    count = count + 1
    print('Before update v2[0]')
    print('v2' + str(v2))
    print('v1' + str(v1))
    v2[0] = d1[0] * v1[0] + d2[0] * v1[1]
    print('After update v2[0]')
    print('v2' + str(v2))
    print('v1' + str(v1))    
    valueFlush = payoff[indexVet] + v1[0] 
    valueWait = d1[indexVet] * v1[indexVet] + d2[indexVet] * v1[indexVet + 1]
    v2[indexVet] = np.maximum( valueFlush, valueWait )
    v2[numStates - 1] = payoff[numStates-1] +  v1[0]
    if ( ( np.max( v2 - v1 ) < 0.0001 ) or ( count > maxIter ) ):
        stopit = True        
    else:
        v1 = v2

这里我尝试使用“while not”来控制我的循环，然后我从输出中看到的是当我执行“v2 [0] = d1 [0] * v1 [0] + d2 [0]行时* v1 [1]“，v2值自动进入v1，就像命令”v1 = v2“被隐式执行一样。我尝试重命名变量，而不是帮助。在执行“v2 [0] = d1 [0] * v1 [0] + d2 [0] * v1 [1]”后，任何人都知道为什么v2等于v1？谢谢！

Answer 1

你的缩进不正确

 private func descriptionAttributedText() -> NSAttributedString {
    let title = "some title on the left side of the screen"
    let subtitle = "subtitle on the right side"

    let rightParagraph = NSMutableParagraphStyle()
    rightParagraph.alignment = .right

    let titleAttributes = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14), NSAttributedStringKey.foregroundColor: UIColor.black]
    let titleString = NSMutableAttributedString(string: title, attributes: titleAttributes)

    let subtitleAttributes = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 13), NSAttributedStringKey.foregroundColor: UIColor.darkGray, NSAttributedStringKey.paragraphStyle: rightParagraph]
    let subtitleString = NSAttributedString(string: subtitle, attributes: subtitleAttributes)

    let paragraph = NSMutableParagraphStyle()
    paragraph.setParagraphStyle(.default)
    paragraph.lineSpacing = 2

    let range = NSMakeRange(0, titleString.string.count)
    titleString.addAttribute(NSAttributedStringKey.paragraphStyle, value: paragraph, range: range)

    titleString.append(subtitleString)


    return titleString
}

应该与while排队，而不是if

即使没有使用命令明确指定，两个ndarray也会隐式地并且自动地彼此相等

1 个答案: