np.array([1,2,3]) |
Creates a 1D array with values 1, 2, 3. (shape 1x3)
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np.array([(1,2,3), (4,5,6)]) |
Creates 2D array of shape 2x3 with values 1,2,3,4,5,6
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np.array([[(1,2,3), (4,5,6)], [(7,8,9), (10,11,12)]]) |
Creates a 3D array with shape 2x2x3
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np.zeros(3,4) |
Creates a 3x4 array of zeros
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np.arrange(1,60,5) |
Creates a 1D array of values 1 through 60 at steps of 5
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a.reshape(2,3,4) |
Reshapes array
a into an array of shape 2x3x4 |
a.shape |
To get the shape of the array
a |
a[0] |
Gets the 0th element in 1D array
a |
b[0,0] |
Gets the 0th element in 2D array
b |
c[0,0,0] |
Gets the 0th element in 3D array
c |
c[9,0,0] |
Gets the element which is the 0th element in the 0th row in the 9th depth
|
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1D arrays
|
|
a[:] |
Selects everything
|
a[2:5] |
Selects the 2nd through the 4th rows (does not include the 5th row)
|
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2D arrays
|
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b[:,:] |
Selects all rows and all columns
|
b[:,0] |
Selects all rows, and the zeroth column
|
b[0,:] |
Selects the zeroth row, and all columns in that row
|
b[0:2,:] |
Selects the zeroth and first row, but NOT the second. It includes all the columns in that row
|
b[0:2,0:2] |
Selects the zeroth and first row, and the zeroth and first column
|
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3D arrays
|
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c[:,:,:] |
Selects all rows and columns on all depths
|
c[0,:,:] |
Selects the everything in the first depth
|
c[:,0,:] |
Selects the first row of each depth
|
c[:,:,0] |
Selects the first column of each depth
|
Cheatography n. The art of mapping complex subjects into clear, instantly navigable reference guides.
