Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array...

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Numpy Ming Ye 2015, modified Beerli 2017

Transcript of Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array...

Page 1: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Numpy

MingYe2015,modifiedBeerli2017

Page 2: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

NumPyisfundamentalpackageforscientificcomputingwithPython

• powerfulN-dimensionalarrayobject• sophisticatedfunctions• basiclinearalgebrafunctions• basicFouriertransforms• sophisticatedrandomnumbercapabilities• toolsforintegratingFortrancode.• toolsforintegratingC/C++code.

Page 3: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Numpyprovides•extensionpackagetoPythonformulti-dimensionalarrays

•closertohardware(efficiency)

•designedforscientificcomputation(convenience)•Alsoknownasarrayorientedcomputing

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NumpyArray

Page 5: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store
Page 6: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Arraysize

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2dimensionalarray

Page 8: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

3dimensionalarray

Page 9: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Arrayinitialization

Page 10: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store
Page 11: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

3dimensionalarray

Page 12: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Datatype

Differentdata-typesallowustostoredatamorecompactlyinmemory,butmostofthetimewesimplyworkwithfloatingpointnumbers.

Page 13: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

wecanexplicitlyspecifydata

Page 14: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Otherdatatypes

Page 15: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Slicesinlistvsarray

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reshape

Ravel:return1-Darrayofinput

unspecified(-1)valueisinferred

Page 17: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

RavelvsFlatten

Flattenreturnsaview

Ravlereturnsacopy

Page 18: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Transposefordimensionshuffling

• IfAisanm×nmatrixthenATisannxmmatrix

Page 19: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Assignment

PROBLEMATIC!

Page 20: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Assignment:TWOPOSSIBLESOLUTIONS

Page 21: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

ndenumerate• Multidimensionalindexiterator.• Returnaniteratoryieldingpairsofarraycoordinatesand

values.

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Addingandmultiplyingelementwise

Page 23: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Matrixmultiplication

array

matrix

Page 24: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

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Manyoperationsworkwitharrays

• abs,cos,sin,...

• accumulate,all

• append,arange,argsort,array_split,matrix,

• asmatrix(notcopied)

• average,copy,cross,delete

• linearalgebra:diagonal,dot,eye,fill,fix,flat(iterator),flatten,indices,inner,insert,item,linspace,mat,maximum,ndim,outer,pinv,repeat,reshape,shape,swapaxis,tile,tolist,transpose,zeros

Page 25: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Convertingnumpyarraytopythonlist

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Example:2DLapacianequation

Numericalsolutionusingfinitedifference

Regularloopvsvectorization

@

2

@x

2+@

2

@y

2=

xx

+

yy

= 0

Page 27: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store
Page 28: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

N=10 N=100 N=1000

loop 0.000897000000002 0.106809 6.922471

Vectorization 0.000724000000002 0.00067 0.023252

comparison

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ReadandWritefiles

• Loadtxt:Constructanarrayfromdatainatextorbinaryfile.

• Savetxt:saveasdelimitatedtext

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Functions

• Functionswithscalararguments

– scalar:float,int

• Functionswitharrayarguments

– automaticallyspeedup

Page 31: Numpy - Peter Beerli · Numpy Array Array size. 2 dimensional array. 3 dimensional array. Array initialization. 3 dimensional array. Data type Different data-types allow us to store

Legate NumPy: Accelerated and Distributed Array Computing · NumPy array objects also act as a common data storage format that can be used to share data between other Python libraries,

Legate NumPy: Accelerated and Distributed Array Computing · NumPy array objects also act as a common data storage format that can be used to share data between other Python libraries,

One Dimensional Array · Two Dimensional Array فٕفهن لٔلأا : حهخاري 2 loops ٗنا جارحذ( ٍٚعثنا خا حفٕفًنا اُع r دَاك ااف 1 فٕفنا

One Dimensional Array · Two Dimensional Array فٕفهن لٔلأا : حهخاري 2 loops ٗنا جارحذ( ٍٚعثنا خا حفٕفًنا اُع r دَاك ااف 1 فٕفنا

Computer Orange Template - MYKVS.INpython.mykvs.in/presentation/class xii/informatics practices/Numpy - Array.pdf · subscript/index determines dimensions of the array. An array of

Computer Orange Template - MYKVS.INpython.mykvs.in/presentation/class xii/informatics practices/Numpy - Array.pdf · subscript/index determines dimensions of the array. An array of

Objeto Array en numpy-Python

Objeto Array en numpy-Python

Ricco Rakotomalala ricco/cours/slides/PH - en - matrices avec... · 4 Array creation R.R. – Université Lyon 2 First, we must import the « NumPy » module import numpy as np np

Ricco Rakotomalala ricco/cours/slides/PH - en - matrices avec... · 4 Array creation R.R. – Université Lyon 2 First, we must import the « NumPy » module import numpy as np np

Arrays. Objectives Declare and initialize a one-dimensional array Store data in a one-dimensional array Display the contents of a one-dimensional array.

Arrays. Objectives Declare and initialize a one-dimensional array Store data in a one-dimensional array Display the contents of a one-dimensional array.

Numpy - CBSE Board) Arraypython.mykvs.in/presentation/class xi/informatics practices/Numpy... · subscript/index determines dimensions of the array. An array of one dimension is known

Numpy - CBSE Board) Arraypython.mykvs.in/presentation/class xi/informatics practices/Numpy... · subscript/index determines dimensions of the array. An array of one dimension is known

Multi dimensional array

Multi dimensional array

One Dimensional Array

One Dimensional Array

Topics to be covered Introduction to array Introduction to array Types of array Types of array One dimensional array One dimensional array Declaration.

Topics to be covered Introduction to array Introduction to array Types of array Types of array One dimensional array One dimensional array Declaration.

Array computing in Python - [Groupe Calcul]calcul.math.cnrs.fr/Documents/Ecoles/2013/python/NumPy introduction... · Array computing in Python Konrad HINSEN Centre de Biophysique

Array computing in Python - [Groupe Calcul]calcul.math.cnrs.fr/Documents/Ecoles/2013/python/NumPy introduction... · Array computing in Python Konrad HINSEN Centre de Biophysique

Lecture 15: High Dimensional Data Analysis, Numpy Overvie€¦ · Point Person: Prof Ingrid Daubechies COMPSCI/MATH 290-04 Lecture 15: High Dimensional Data Analysis, Numpy Overview.

Lecture 15: High Dimensional Data Analysis, Numpy Overvie€¦ · Point Person: Prof Ingrid Daubechies COMPSCI/MATH 290-04 Lecture 15: High Dimensional Data Analysis, Numpy Overview.

Hands-on Lab: Deep Learning with the Theano Python Library · Introduction Theano Models Exercices NumPy/SciPy I NumPy provides an n -dimensional numeric array in Python I Perfect

Hands-on Lab: Deep Learning with the Theano Python Library · Introduction Theano Models Exercices NumPy/SciPy I NumPy provides an n -dimensional numeric array in Python I Perfect

Polk Audio Stereo Dimensional Array Vintage Speakers

Polk Audio Stereo Dimensional Array Vintage Speakers

media.readthedocs.org · CHAPTER 1 Overview CuPyis an implementation of NumPy-compatible multi-dimensional array on CUDA. CuPy consists of cupy. ndarray, the core multi-dimensional

media.readthedocs.org · CHAPTER 1 Overview CuPyis an implementation of NumPy-compatible multi-dimensional array on CUDA. CuPy consists of cupy. ndarray, the core multi-dimensional

The NumPy Array: A Structure for Efficient Numerical Computation · 2012-09-03 · The NumPy Array: A Structure for Efficient Numerical Computation Presented at the G-Node Autumn

The NumPy Array: A Structure for Efficient Numerical Computation · 2012-09-03 · The NumPy Array: A Structure for Efficient Numerical Computation Presented at the G-Node Autumn

numPy Python packages and Libraries - WordPress.com · Python, NumPy. What is NumPy? NumPy is a general-purpose array-processing package. It provides a high-performance multidimensional

numPy Python packages and Libraries - WordPress.com · Python, NumPy. What is NumPy? NumPy is a general-purpose array-processing package. It provides a high-performance multidimensional

viterbi.usc.edu · Web viewThree-dimensional crossbar array systems and methods for writing information to and reading information stored in three-dimensional crossbar array junctions

viterbi.usc.edu · Web viewThree-dimensional crossbar array systems and methods for writing information to and reading information stored in three-dimensional crossbar array junctions

NumPy / SciPy and Array-Oriented Computing Travis Oliphant, PhD PyCodeConf

NumPy / SciPy and Array-Oriented Computing Travis Oliphant, PhD PyCodeConf

ARRAYS - Nathaniel G. Martinds.nathanielgmartin.com/wk01/W1L3-Arrays.pdf · 2016. 12. 30. · g e o f E n g g. 5 Types of Array ARRAYS One Dimensional Array Multi Dimensional Array

ARRAYS - Nathaniel G. Martinds.nathanielgmartin.com/wk01/W1L3-Arrays.pdf · 2016. 12. 30. · g e o f E n g g. 5 Types of Array ARRAYS One Dimensional Array Multi Dimensional Array