NumPy Tutorial presented at SciPy2010

Kittens&DragonsNumPyTutorialpresentedatSciPy2010Stéfan van der WaltStellenbosch University, South Africa28 June 2010 Setup• Tutorial layout• Setup import numpy as npThe NumPy ndarrayprint np.__version__ # version 1.3 or greaterBroadcastingIndexingStructured arrays Point your browser to the problem set atUniversal functionshttp://mentat.za.net/numpy/kittensThe __array_interface__OptimisationUpdate, wrap-up & questions9th Python in Science Conference (SciPy) 2010 3 / 48• Tutorial layout• SetupThe NumPy ndarray• ndarray• Rating: Kitten• Data buffers• Dimensions• Data-type• Strides• Flags• Base Pointer• TheNumPyndarrayBroadcastingIndexingStructured arraysUniversal functionsThe __array_interface__OptimisationUpdate, wrap-up & questions9th Python in Science Conference (SciPy) 2010 4 / 48Revision: Structureofanndarray• Tutorial layout Taking a look atnumpy/core/include/numpy/ndarraytypes.h:• SetupThe NumPy ndarray• ndarray• Rating: Kitten typedef struct PyArrayObject {• Data buffersPyObject_HEAD• Dimensions• Data-type char *data; /* pointer to data buffer */• Stridesint nd; /* number of dimensions */• Flags• Base Pointer npy_intp *dimensions; /* size in each dimension */•npy_intp *strides; /* bytes to jump to getBroadcasting* to the next element inIndexing* each ...