NumPy from beginner to advanced
preface
I Getting started with Numpy
NumPy (Numerical Python) is an open source numerical calculation extension of Python. It provides multidimensional array objects and various derived objects (such as mask arrays and matrices). This tool can be used to store and process large matrices, which is much more efficient than Python's own nest ...
Posted by feign3 on Tue, 18 Jan 2022 16:16:27 +0100
Python math library Numpy getting started creating arrays
install
c:\> pip install numpy -i https://pypi.tuna.tsinghua.edu.cn/simple
Official Guide
NumPy quickstart — NumPy v1.22 Manualhttps://numpy.org/doc/stable/user/quickstart.html
>>> import numpy
>>> help(numpy)
Squeezed text(75939 lines).
>>>
There are nearly 76000 lines of internal help documents. Choosing so ...
Posted by djsl on Tue, 18 Jan 2022 02:43:59 +0100
Translation of articles on numpy official website
Official website addressWhat is numpynumpy is a scientific computing package for Python. It provides a variety of array objects, derived objects (masked arrays and matrices) and their daily fast operations, including mathematics, logic, shape operation, classification, selection, I/O, discrete Fourier transforms, basic linear algebra, basic dat ...
Posted by Kifebear on Sun, 16 Jan 2022 03:23:34 +0100
Basic Python data analysis tutorial: NumPy Learning Guide (2nd Edition) note 15: Chapter 7 special function 1 - sorting
Chapter VII Special Functions
This chapter mainly introduces Numpy function in financial calculation or signal processing.
7.1 sorting
NumPy provides a variety of sorting functions, as shown below:
The sort function returns the sorted array;The lexport function sorts according to the dictionary order of key values;The argsort function retur ...
Posted by system_critical on Fri, 14 Jan 2022 13:01:43 +0100
Python learning notes
preface
A learning channel of Python numpy Library
1, Basic index and slicing of ndarray
Like a sequence, ndarray can also perform indexing and slicing operations. The index start sequence number also starts from 0, and ndarray can be performed in different dimensions.
① Index and slice of one-dimensional array
The inde ...
Posted by just_nobody on Thu, 06 Jan 2022 08:39:45 +0100
Look at the 12 efficient Numpy&Pandas skills. You'll lose if you don't look at them
In this paper, we share 12 kinds of Numpy and Pandas functions. These efficient functions will make data analysis easier and convenient. Finally, readers can also find the Jupyter Notebook of the code used in this article in the GitHub project.Project address: https://github.com/kunaldhariwal/12-Amazing-Pandas-NumPy-FunctionsSix efficient funct ...
Posted by Caps on Sun, 26 Dec 2021 12:47:55 +0100
Wu Enda's machine learning assignment -- anomaly detection and recommendation system
anomaly detection
reference material: https://github.com/fengdu78/Coursera-ML-AndrewNg-Notes Look at the data first:
import numpy as np
import matplotlib.pyplot as plt
from scipy import stats
from scipy.io import loadmat
import math
data = loadmat('data/ex8data1.mat') # Xval,yval,X
X = data['X']
Xval = data['Xval']
yval = data['yval']
plt.s ...
Posted by m00nz00mer on Sun, 26 Dec 2021 10:16:23 +0100
numpy of Python module
Briefly write the function definitions of the modules commonly used in Python to facilitate subsequent search (excerpt from Python):
Numpy
Create a numpy array (array a will be used for demonstration later):
a = np.array([[1,2,3],[4,5,6]])
The following statements are usually used to import numpy:
import numpy as np
Then follow up w ...
Posted by legomez2000 on Sat, 25 Dec 2021 12:56:35 +0100
Summary of 18 practical Numpy code fragments
Numpy has long been a universal choice for Python developers to perform array operations. It is built based on C language, which makes it a fast and reliable choice to perform array operations, and it has become a necessary basic library for machine learning and data science.In this article, I sorted out some fragments of NumPy code, which are ...
Posted by jannoy on Wed, 15 Dec 2021 03:28:55 +0100
Numpy: array oriented programming
Using numpy array allows us to use simple array expressions to complete a variety of data operation tasks without writing a large number of loops (avoiding loops is the core idea). This method of using array expressions instead of displaying loops is called vectorization. Generally, vectorized array operations are one or two orders of magnitude ...
Posted by nemo on Wed, 08 Dec 2021 11:27:31 +0100