dimod.SampleSet.slice#

SampleSet.slice(*slice_args, **kwargs)[source]#

Create a new sample set with rows sliced according to standard Python slicing syntax.

Parameters:

  • start (int, optional, default=None) – Start index for slice.

  • stop (int) – Stop index for slice.

  • step (int, optional, default=None) – Step value for slice.

  • sorted_by (str/None, optional, default='energy') – Selects the record field used to sort the samples before slicing. Note that sorted_by determines the sample order in the returned sample set.

Returns:

SampleSet

Examples

>>> import numpy as np
...
>>> sampleset = dimod.SampleSet.from_samples(np.diag(range(1, 11)),
...                   dimod.BINARY, energy=range(10))
>>> print(sampleset)
   0  1  2  3  4  5  6  7  8  9 energy num_oc.
0  1  0  0  0  0  0  0  0  0  0      0       1
1  0  1  0  0  0  0  0  0  0  0      1       1
2  0  0  1  0  0  0  0  0  0  0      2       1
3  0  0  0  1  0  0  0  0  0  0      3       1
4  0  0  0  0  1  0  0  0  0  0      4       1
5  0  0  0  0  0  1  0  0  0  0      5       1
6  0  0  0  0  0  0  1  0  0  0      6       1
7  0  0  0  0  0  0  0  1  0  0      7       1
8  0  0  0  0  0  0  0  0  1  0      8       1
9  0  0  0  0  0  0  0  0  0  1      9       1
['BINARY', 10 rows, 10 samples, 10 variables]

The above example’s first 3 samples by energy == truncate(3):

>>> print(sampleset.slice(3))
   0  1  2  3  4  5  6  7  8  9 energy num_oc.
0  1  0  0  0  0  0  0  0  0  0      0       1
1  0  1  0  0  0  0  0  0  0  0      1       1
2  0  0  1  0  0  0  0  0  0  0      2       1
['BINARY', 3 rows, 3 samples, 10 variables]

The last 3 samples by energy:

>>> print(sampleset.slice(-3, None))
   0  1  2  3  4  5  6  7  8  9 energy num_oc.
0  0  0  0  0  0  0  0  1  0  0      7       1
1  0  0  0  0  0  0  0  0  1  0      8       1
2  0  0  0  0  0  0  0  0  0  1      9       1
['BINARY', 3 rows, 3 samples, 10 variables]

Every second sample in between, skipping top and bottom 3:

>>> print(sampleset.slice(3, -3, 2))
   0  1  2  3  4  5  6  7  8  9 energy num_oc.
0  0  0  0  1  0  0  0  0  0  0      3       1
1  0  0  0  0  0  1  0  0  0  0      5       1
['BINARY', 2 rows, 2 samples, 10 variables]