how to find area of rectangle which is covering another rectangle

I have a list of point [xmin,ymin,xmax,ymax] for each as show by black point How to find which are the rectangles that are being covered by another rectangle and how much it is being covered .the algorithm should be efficient. one solution would be to check every rectangle with each other rectangle which would take a time complexity of O(n^2) , but I need efficient algorithm. Note that there

如何找到覆盖另一个矩形的矩形区域

我有一个点[xmin,ymin,xmax,ymax]的列表,如黑点所示 如何找到哪个矩形被另一个矩形覆盖,以及它被覆盖多少。算法应该是有效的。 一种解决方案是检查每个矩形与每个矩形的时间复杂度为O(n ^ 2),但我需要高效的算法。 请注意,图像中显示了许多这样的矩形,红色的应该被检测出去,绿色应该被保留。 输入是n矩形输出是覆盖区域和它覆盖的矩形ID。 最好给出一些算法和解释。 假设矩形列表是L并且说只有绿色列表的最

Evaluate math expression within string

I have a question concerning evaluation of math expression within a string. For example my string is following: my_str='I have 6 * (2 + 3) apples' I am wondering how to evaluate this string and get the following result: 'I have 30 apples' Is the any way to do this? Thanks in advance. PS python's eval function does not help in this case. It raised an error, when trying to evaluate wi

评估字符串内的数学表达式

我有一个关于字符串内数学表达式评估的问题。 例如我的字符串如下: my_str='I have 6 * (2 + 3) apples' 我想知道如何评估这个字符串,并得到以下结果: 'I have 30 apples' 有没有办法做到这一点? 提前致谢。 PS python的eval函数在这种情况下不起作用。 当尝试使用eval函数进行评估时,它引发了一个错误。 这是我的尝试: >>> import string >>> s = 'I have 6 * (2+3) apples' >>>

Using Google OAuth2 with Flask

Can anyone point me to a complete example for authenticating with Google accounts using OAuth2 and Flask, and not on App Engine? I am trying to have users give access to Google Calendar, and then use that access to retrieve information from the calendar and process it further. I also need to store and later refresh the OAuth2 tokens. I have looked at Google's oauth2client library and can

在Flask中使用Google OAuth2

任何人都可以指出我使用OAuth2和Flask进行身份验证的完整示例,而不是App Engine? 我试图让用户授予Google日历访问权限,然后使用该访问权限从日历中检索信息并进一步处理。 我还需要存储并稍后刷新OAuth2令牌。 我查看了Google的oauth2client库,并且可以开始跳舞以检索授权码,但是我有点失落。 查看Google的OAuth 2.0 Playground我明白我需要请求刷新令牌和访问令牌,但库中提供的示例仅适用于App Engine和Django。

Efficiently compute sum of N smallest numbers in an array

I have a code where first I need to sort values and then I need to sum the first 10 elements. I would love to use Numba package to speed the run time, but it is not working, Numba is getting the code slower than just Numpy. My first test, just for sum: import numpy as np import numba np.random.seed(0) def SumNumpy(x): return np.sum(x[:10]) @numba.jit() def SumNumpyNumba(x): return n

有效计算数组中N个最小数字的和

我有一个代码,首先我需要排序值,然后我需要总结前10个元素。 我很乐意使用Numba软件包来加速运行时间,但它不起作用,Numba的代码比Numpy慢。 我的第一个测试,只是为了总结: import numpy as np import numba np.random.seed(0) def SumNumpy(x): return np.sum(x[:10]) @numba.jit() def SumNumpyNumba(x): return np.sum(x[:10]) 我的测试: x = np.random.rand(1000000000) %timeit SumNumpy(x) %timeit S

Optimizing Many Matrix Operations in Python / Numpy

In writing some numerical analysis code, I have bottle-necked at a function that requires many Numpy calls. I am not entirely sure how to approach further performance optimization. Problem: The function determines error by calculating the following, Code: def foo(B_Mat, A_Mat): Temp = np.absolute(B_Mat) Temp /= np.amax(Temp) return np.sqrt(np.sum(np.absolute(A_Mat - Temp*Temp)

在Python / Numpy中优化许多矩阵操作

在编写一些数字分析代码时,我对一个需要许多Numpy调用的函数进行了分析。 我不完全确定如何进一步的性能优化。 问题: 该功能通过计算以下内容来确定错误, 码: def foo(B_Mat, A_Mat): Temp = np.absolute(B_Mat) Temp /= np.amax(Temp) return np.sqrt(np.sum(np.absolute(A_Mat - Temp*Temp))) / B_Mat.shape[0] 从代码中挤出一些额外性能的最佳方法是什么? 我的最佳行动方案是用Cython在单个for循

Iterating over arrays in cython, is list faster than np.array?

TLDR: in cython, why (or when?) is iterating over a numpy array faster than iterating over a python list? Generally: I've used Cython before and was able to get tremendous speed ups over naive python impl', However, figuring out what exactly needs to be done seems non-trivial. Consider the following 3 implementations of a sum() function. They reside in a cython file called 'cy

迭代cython中的数组,列表比np.array更快吗?

TLDR:在cython中,为什么(或者什么时候?)遍历一个numpy数组比迭代python列表更快? 一般来说:我之前使用过Cython,并且能够在天真的python impl上获得巨大的提速。然而,搞清楚究竟需要做什么似乎并不重要。 考虑sum()函数的以下3个实现。 他们居住在一个名为'cy'的cython文件中(很显然,这里有np.sum(),但除此之外,这是我的观点。) 朴素蟒蛇: def sum_naive(A): s = 0 for a in A: s

Cython either marginally faster or slower than pure Python

I am using several techniques ( NumPy , Weave and Cython ) to perform a Python performance benchmark. What the code basically does mathematically is C = AB , where A, B and C are N x N matrices ( NOTE: this is a matrix product and not an element-wise multiplication). I have written 5 distinct implementations of the code: Pure python (Loop over 2D Python lists) NumPy (Dot product of 2D NumP

Cython比纯Python要稍快或慢一些

我使用几种技术( NumPy , Weave和Cython )来执行Python性能基准测试。 代码基本上在数学上做的是C = AB ,其中A,B和C是N x N矩阵( 注意:这是一个矩阵乘积而不是单元乘法)。 我写了5个不同的代码实现: 纯Python(循环遍历2D Python列表) NumPy(2D NumPy数组的点积) 内联编织(二维数组上的C ++循环) Cython(循环二维Python列表+静态类型) Cython-Numpy(循环遍历2D NumPy数组+静态类型) 我的期望是

How to create a custom numpy dtype using cython

There are examples for creating custom numpy dtypes using C here: Additionally, it seems to be possible to create custom ufuncs in cython: It seems like it should also be possible to create a dtype using cython (and then create custom ufuncs for it). Is it possible? If so, can you post an example? USE CASE: I want to do some survival analysis. The basic data elements are survival times

如何使用cython创建自定义numpy dtype

这里有一些使用C创建自定义numpy dtypes的例子: 另外,它似乎可以在cython中创建自定义的ufuncs: 它似乎也应该可以使用cython创建一个dtype(然后为它创建自定义的ufuncs)。 可能吗? 如果是这样,你可以发布一个例子吗? 使用案例: 我想做一些生存分析。 基本数据元素是具有相关传感器值的生存时间(浮点数)(如果相关时间表示失败时间则为假,如果它代表截尾时间(即在观察期间未发生失败)则为真)。 很明

cython memoryview slower than expected

I've started using memoryviews in cython to access numpy arrays. One of the various advantages they have is that they are considerably faster than the old numpy buffer support: http://docs.cython.org/src/userguide/memoryviews.html#comparison-to-the-old-buffer-support However, I have an example where the old numpy buffer support is faster than memoryviews! How can this be?! I wonder if I&

cython memoryview比预期慢

我已经开始在cython中使用memoryviews来访问numpy数组。 他们拥有的各种优点之一是它们比旧的numpy缓冲区支持要快得多:http://docs.cython.org/src/userguide/memoryviews.html#comparison-to-the-old-buffer-support 但是,我有一个例子,其中旧的numpy缓冲区支持比memoryviews更快! 怎么会这样?! 我想知道我是否正确使用了记忆体? 这是我的测试: import numpy as np cimport numpy as np cimport cython @cython

Finding direct child of an element

I'm writing a solution to test this phenomenon in Python. I have most of the logic done, but there are many edge cases that arise when following links in Wikipedia articles. The problem I'm running into arises for a page like this where the first <p> has multiple levels of child elements and the first <a> tag after the first set of parentheses needs to be extracted. In thi

找到元素的直接子元素

我正在编写一个解决方案来在Python中测试这种现象。 我完成了大部分逻辑,但在维基百科文章中关注链接时会出现许多边缘案例。 我遇到的问题出现在这样一个页面上,其中第一个<p>具有多个子级元素,第一个括号之后的第一个<a>标签需要提取。 在这种情况下(为了提取这个链接),你必须跳过括号,然后到达下一个定位标记/ href。 在大多数文章中,我的算法可以跳过括号,但是以它在圆括号前面寻找链接的方式(或