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@ -1705,12 +1705,36 @@ import numpy as np |
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``` |
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```python |
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<el_or_array> = <array>[:,0] # First column. |
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<el_or_array> = <array>.sum([<axis>]) # Axis is an index of dimension that gets collapsed. |
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<el_or_array> = <array>.argmin([<axis>]) # Returns index/es of smallest elements. |
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<el_or_array> = <array>[filter_expression] |
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<el_or_array> = <array>.sum([<axis>]) # Axis is an index of dimension that gets collapsed. |
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<el_or_array> = <array>.argmin([<axis>]) # Returns index/es of smallest element/s. |
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``` |
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### Indexing |
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#### Basic indexing |
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```python |
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<el> = <2d_array>[0, 0] |
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``` |
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#### Basic slicing |
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```python |
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<1d_view> = <2d_array>[0] # First row. |
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<1d_view> = <2d_array>[:, 0] # First column. Also [..., 0]. |
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<3d_view> = <2d_array>[None,:,:] # Expanded by dimension of size 1. |
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``` |
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#### Integer array indexing |
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**If row and column indexes differ in shape, they are combined with broadcasting.** |
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```python |
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<1d_array> = <2d_array>[<1d_row_indexes>, <1d_column_indexes>] |
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<2d_array> = <2d_array>[<2d_row_indexes>, <2d_column_indexes>] |
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``` |
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#### Boolean array indexing |
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```python |
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<2d_bool_array> = <2d_array> > 0 |
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<1d_array> = <2d_array>[<2d_bool_array>] |
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`` |
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### Broadcasting |
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**Broadcasting is a set of rules by which NumPy functions operate on arrays of different sizes and/or dimensions.** |
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```python |
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