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Method argpartition
NumPy Random Generator4 topics
Method choiceMethod dotMethod finfoMethod histogramMethod iinfoMethod maxMethod meanMethod placeMethod rootsMethod seedMethod uniformMethod viewMethod zerosMethod sumObject busdaycalendarMethod is_busdayProperty dtypeMethod uniqueMethod loadtxtMethod vsplitMethod fliplrMethod setdiff1dMethod msortMethod argsortMethod lexsortMethod aroundMethod nanmaxMethod nanminMethod nanargmaxMethod nanargminMethod argmaxMethod argminProperty itemsizeMethod spacingMethod fixMethod ceilMethod diffProperty flatProperty realProperty baseMethod flipMethod deleteMethod amaxMethod aminMethod logical_xorMethod logical_orMethod logical_notMethod logical_andMethod logaddexpMethod logaddexp2Method logspaceMethod not_equalMethod equalMethod greater_equalMethod lessMethod less_equalMethod remainderMethod modMethod emptyMethod greaterMethod isfiniteMethod busday_countMethod repeatMethod varMethod random_sampleMethod randomMethod signMethod stdMethod absoluteMethod absMethod sortMethod randintMethod isrealMethod linspaceMethod gradientMethod allMethod sampleProperty TProperty imagMethod covMethod insertMethod logMethod log1pMethod exp2Method expm1Method expMethod arccosMethod cosMethod arcsinMethod sinMethod tanMethod fromiterMethod trim_zerosMethod diagflatMethod savetxtMethod count_nonzeroProperty sizeProperty shapeMethod reshapeMethod resizeMethod triuMethod trilMethod eyeMethod arangeMethod fill_diagonalMethod tileMethod saveMethod transposeMethod swapaxesMethod meshgridProperty mgridMethod rot90Method log2Method radiansMethod deg2radMethod rad2degMethod degreesMethod log10Method appendMethod cumprodProperty nbytesMethod tostringProperty dataMethod modfMethod fmodMethod tolistMethod datetime_as_stringMethod datetime_dataMethod array_splitMethod itemsetMethod floorMethod put_along_axisMethod cumsumMethod bincountMethod putMethod putmaskMethod takeMethod hypotMethod sqrtMethod squareMethod floor_divideMethod triMethod signbitMethod flattenMethod ravelMethod rollMethod isrealobjMethod diagMethod diagonalMethod quantileMethod onesMethod iscomplexobjMethod iscomplexMethod isscalarMethod divmodMethod isnatMethod percentileMethod isnanMethod divideMethod addMethod reciprocalMethod positiveMethod subtractMethod medianMethod isneginfMethod isposinfMethod float_powerMethod powerMethod negativeMethod maximumMethod averageMethod isinfMethod multiplyMethod busday_offsetMethod identityMethod interpMethod squeezeMethod get_printoptionsMethod savez_compressedMethod savezMethod loadMethod asfarrayMethod clipMethod arrayMethod array_equivMethod array_equalMethod frombufferMethod set_string_functionMethod matmulMethod genfromtxtMethod fromfunctionMethod asscalarMethod searchsortedMethod full_likeMethod fullMethod shares_memoryMethod ptpMethod digitizeMethod argwhereMethod geomspaceMethod zeros_likeMethod fabsMethod flatnonzeroMethod vstackMethod dstackMethod fromstringMethod tobytesMethod expand_dimsMethod ranfMethod arctanMethod itemMethod extractMethod compressMethod chooseMethod asarrayMethod asmatrixMethod allcloseMethod iscloseMethod anyMethod corrcoefMethod truncMethod prodMethod crossMethod true_divideMethod hsplitMethod splitMethod rintMethod ediff1dMethod lcmMethod gcdMethod cbrtMethod flipudProperty ndimMethod array2stringMethod set_printoptionsMethod whereMethod hstack
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chevron_left Documentation
Method argpartition
NumPy Random Generator4 topics
Method choiceMethod dotMethod finfoMethod histogramMethod iinfoMethod maxMethod meanMethod placeMethod rootsMethod seedMethod uniformMethod viewMethod zerosMethod sumObject busdaycalendarMethod is_busdayProperty dtypeMethod uniqueMethod loadtxtMethod vsplitMethod fliplrMethod setdiff1dMethod msortMethod argsortMethod lexsortMethod aroundMethod nanmaxMethod nanminMethod nanargmaxMethod nanargminMethod argmaxMethod argminProperty itemsizeMethod spacingMethod fixMethod ceilMethod diffProperty flatProperty realProperty baseMethod flipMethod deleteMethod amaxMethod aminMethod logical_xorMethod logical_orMethod logical_notMethod logical_andMethod logaddexpMethod logaddexp2Method logspaceMethod not_equalMethod equalMethod greater_equalMethod lessMethod less_equalMethod remainderMethod modMethod emptyMethod greaterMethod isfiniteMethod busday_countMethod repeatMethod varMethod random_sampleMethod randomMethod signMethod stdMethod absoluteMethod absMethod sortMethod randintMethod isrealMethod linspaceMethod gradientMethod allMethod sampleProperty TProperty imagMethod covMethod insertMethod logMethod log1pMethod exp2Method expm1Method expMethod arccosMethod cosMethod arcsinMethod sinMethod tanMethod fromiterMethod trim_zerosMethod diagflatMethod savetxtMethod count_nonzeroProperty sizeProperty shapeMethod reshapeMethod resizeMethod triuMethod trilMethod eyeMethod arangeMethod fill_diagonalMethod tileMethod saveMethod transposeMethod swapaxesMethod meshgridProperty mgridMethod rot90Method log2Method radiansMethod deg2radMethod rad2degMethod degreesMethod log10Method appendMethod cumprodProperty nbytesMethod tostringProperty dataMethod modfMethod fmodMethod tolistMethod datetime_as_stringMethod datetime_dataMethod array_splitMethod itemsetMethod floorMethod put_along_axisMethod cumsumMethod bincountMethod putMethod putmaskMethod takeMethod hypotMethod sqrtMethod squareMethod floor_divideMethod triMethod signbitMethod flattenMethod ravelMethod rollMethod isrealobjMethod diagMethod diagonalMethod quantileMethod onesMethod iscomplexobjMethod iscomplexMethod isscalarMethod divmodMethod isnatMethod percentileMethod isnanMethod divideMethod addMethod reciprocalMethod positiveMethod subtractMethod medianMethod isneginfMethod isposinfMethod float_powerMethod powerMethod negativeMethod maximumMethod averageMethod isinfMethod multiplyMethod busday_offsetMethod identityMethod interpMethod squeezeMethod get_printoptionsMethod savez_compressedMethod savezMethod loadMethod asfarrayMethod clipMethod arrayMethod array_equivMethod array_equalMethod frombufferMethod set_string_functionMethod matmulMethod genfromtxtMethod fromfunctionMethod asscalarMethod searchsortedMethod full_likeMethod fullMethod shares_memoryMethod ptpMethod digitizeMethod argwhereMethod geomspaceMethod zeros_likeMethod fabsMethod flatnonzeroMethod vstackMethod dstackMethod fromstringMethod tobytesMethod expand_dimsMethod ranfMethod arctanMethod itemMethod extractMethod compressMethod chooseMethod asarrayMethod asmatrixMethod allcloseMethod iscloseMethod anyMethod corrcoefMethod truncMethod prodMethod crossMethod true_divideMethod hsplitMethod splitMethod rintMethod ediff1dMethod lcmMethod gcdMethod cbrtMethod flipudProperty ndimMethod array2stringMethod set_printoptionsMethod whereMethod hstack
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NumPy | take method

NumPy
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schedule Jul 1, 2022
Last updated
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Numpy's take(~) method is used to access values, rows and columns of an array.

Parameters

1. a | array_like

The array to perform the method on.

2. indices | number or array_like

The indices of the values to be fetched. If you provide a number type, then you're accessing a single value, row or column in the array. If array_like type is provided, then you're accessing multiple rows/columns.

3. axis | number | optional

The axis along which to select values. By default, axis=None, that is, your input array a will be deemed as a flattened array.

Return value

Depending on the parameters, the return type will differ.

  • If no axis is provided, then you get a number since you're just accessing a single value.

  • If axis is provided, then you get a Numpy array since you're accessing a row or a column.

Examples

Accessing a single value in a matrix

x = [[4,5,6], [7,8,9]]
np.take(x, 1)
5

Remember, if you provide a number type for the second argument, then Numpy will treat your input array as a flattened array, that is, x=[4,5,6,7,8,9]. In this example, we're taking the first index of this flattened array, and so the value 5 is returned.

Accessing a single row of a matrix

To access a row of a matrix, supply the parameter axis=0.

x = [[4,5,6], [7,8,9]]
np.take(x, 1, axis=0)
array([7, 8, 9])

To clarify what this code is doing, we're just fetching the 2nd row (i.e. rows also follow index order, so that's why we set 1 as the second argument):

$$\begin{pmatrix} 4&5&6\\ \color{red}{7}&\color{red}{8}&\color{red}{9}\\ \end{pmatrix}$$

Accessing a single column of a matrix

To access a column of a matrix, supply the parameter axis=1.

x = [[4,5,6], [7,8,9]]
np.take(x, 1, axis=1)
array([5, 8])

To clarify what this code is doing, we're just fetching the 2nd column (i.e. columns also follow index order, so that's why we set 1 as the second argument):

$$\begin{pmatrix} 4&\color{red}{5}&6\\ 7&\color{red}{8}&9\\ \end{pmatrix}$$

Accessing multiple rows of a matrix

To access multiple columns of a matrix, supply the parameter axis=0, and provide type array-like for the second argument:

x = [[4,5,6], [7,8,9]]
np.take(x, [0,1], axis=0)
array([[4, 5, 6],
[7, 8, 9]])

We're accessing 1st and 2nd rows, as in:

$$\begin{pmatrix} \color{red}{4}&\color{red}{5}&\color{red}{6}\\ \color{red}{7}&\color{red}{8}&\color{red}{9}\\ \end{pmatrix}$$

Accessing multiple columns of a matrix

To access multiple columns of a matrix, supply the parameter axis=1, and provide type array-like for the second argument:

x = [[4,5,6], [7,8,9]]
np.take(x, [0,2], axis=1)
array([[4, 6],
[7, 9]])

We're accessing the 1st and 3rd columns, as in:

$$\begin{pmatrix} \color{red}{4}&5&\color{red}{6}\\ \color{red}{7}&8&\color{red}{9}\\ \end{pmatrix}$$
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