involves the calculation of a large amount of data there are multiple loops nested within the use of pandas for calculation extremely slow is there any effective way to speed up? ...
vector = np.array ([2Jing 4 Jing 6 Jing 8 Jing 10]) deal with 1: 2 to 4 elements, take the reverse vector = np.array([1,2,3,4,5,6]) vector[vector>2] vector[np.where(vector>3)] processing 2: reverse values greater than 2 and less than 8 : vecto...
how to query data in B dataframe according to the ID, of A dataframe in pandas, An and B tables have the same ID column. Similar to SQL s column-level subquery: select * from t_class where c_id in (select c_class_id from t_student) , An and B have an o...
Why do two list-to-np.array, datatypes of exactly the same type become object, and the other floatable! print(len(X_l)) -sharp 2013 print(len(X_s)) -sharp 1980 print(X_l[0].dtype) -sharp float64 print(X_s[0].dtype) -sharp float64 print(X_l[0].shape) ...
didn t GMP say the fastest large number operation library on earth? ...
1. When I am converting the real data of two dataframe tables into numpy data for column content comparison, I encounter the following situations: input: individual elements of different arrays d12.values [0] [0], d12.values [1] [0], d11.values [...
topic description use the numpy gradient function to calculate the gradient related codes Please paste the code text below (do not replace the code with pictures) g = img [0 3, 0:3] g = array ([[138144141], [134, 135, 132], [137, 1...
problem description The matrix is as follows: 1,2017,2,5 1,2018,1,5 1,2018,2,4 2,2017,1,5 1,2018,1,2 according to the first three columns, there are three kinds of matrix to produce a new matrix: 1,2017,2,5 1,2018,1,7 1,2018,2,4 2,2017,1,5 one li...
for example, numpy, I looked at the package structure of numpy on github and found that numpy is a package, but its _ _ init__.py file does not have a function definition such as ones (), and there is no import reference to it, so why can I write numpy.o...
binom is a binomial distribution, so what is the distribution of nbinom? Looking at their calculation formulas, it is only in the combination that the total number and the number of occurrences are reduced by 1 ....
ask God to explain how the results of this a [iMagnej] are all taken out of a. Why do I not understand the meaning expressed by [iMagnej] ? ...
coding can be implemented in all four of the above methods. What s the difference between them? Of course, the length of the script is different. I can already see it. < H1 > get_dummies method < H1 > df7 = DataFrame({ key :list( bbacab ), ...
when using pip3 to install arch and ffn python packages under Ubuntu16.04LTS system python3.5.2, it is always prompted: Could not find a version that satisfies the requirement numpy==1.9.3 No matching distribution found for numpy==1.9.3 this error is...
this is a basic random walk problem. according to the contents of the book, I try to find indexes on axis=1 whose absolute value is greater than or equal to 7, but there are always several rows whose index is 0, and the index entered normally is fine....
1. According to Google s official machine learning course code, there is no problem when executing in an interactive environment, but an error will be reported when executed in vscode; the 2.python code is as follows: import numpy as np np.random.p...
as mentioned above, I am going to save about 30, 000 pictures in numpy format first, so that it will be much more convenient and faster to use later. but in the process of running, it seems that there is an error due to insufficient memory, which is r...
I now have a batch of images that I want to convert to numpy data to save, but the image size is not fixed (I don t want resize) for example, a. Shapee = (3rec 2jue 9), b. Shapee = (3pr 3pr 8), how to merge a meme b into c? That is to say, to realize...
I have just learned about WeChat Mini Programs, but I don t understand the applicable scenarios of wx.login and wx.getUserinfo. It seems that a code, will be returned in wx.login and then the user s openid can be obtained by requesting the interface pr...
recently, when writing a unit test for a component, the test filter found a small problem. I ve seen the source code of vue, and I ve found that vue is an expression that compiles a node into _ f () {} if it encounters a filter during compilation. The...
large models do not open wireframes by default, while small models load wireframes by default as a developer, I hope I can have an API that can customize the effect of switching wireframes in order to adapt to different project needs. ...
for example, why do you respond to http requests by adding @ Controller annotations? ...
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