python-watarray is a python wrappers for wat-array, a wavelet tree library.
- Python>=2.4
- wat-array==0.06
$ git clone git://github.com/fuzzysphere/python-watarray.git
$ cd python-watarray
$ python setup.py build
$ python setup.py install>>> import watarray
>>> wa = watarray.WatArray()
>>> A = [5, 1, 0, 4, 2, 2, 0, 3]
>>> wa.Init(A)
>>> wa.length()
8L
>>> wa.Lookup(3)
4L
>>> wa.Rank(2, 6)
2L
>>> wa.Select(2, 2)
5L
>>> wa.RankLessThan(4, 5)
3L
>>> wa.RankMoreThan(4, 5)
1L
>>> wa.FreqRange(2, 5, 2, 6)
3L
>>> wa.RankAll(4, 5)
(1L, 3L, 1L)
>>> wa.RankAll(7, 5) == (watarray.NOTFOUND, watarray.NOTFOUND, watarray.NOTFOUND)
True
>>> wa.MaxRange(1, 6)
(3L, 4L)
>>> wa.MinRange(1, 6)
(2L, 0L)
>>> wa.QuantileRange(1, 6, 3)
(4L, 2L)
>>> wa.ListModeRange(2, 5, 1, 6, 3)
[(2L, 2L), (4L, 1L)]
>>> wa.ListMinRange(1, 5, 1, 6, 3)
[(1L, 1L), (2L, 2L), (4L, 1L)]
>>> wa.ListMaxRange(1, 5, 1, 6, 3)
[(4L, 1L), (2L, 2L), (1L, 1L)]
>>> data = wa.dumps()
>>> wa.Clear()
>>> wa.length()
0L
>>> wa.loads(data)
>>> wa.length()
8L
>>> del waAn instance of WatArray has the following methods.
| Init(A) | Create wat-array from A. |
| length() | Return the length of A. |
| alphabet_num() | Return the number of alphabet (max value in A + 1) of A. |
| Freq(c) | Return the number of c in A. |
| Lookup(pos) | Return A[pos]. |
| Rank(c, pos) | Return the number of c in A[0:pos]. |
| Select(c, rank) | Return the position of the (rank)-th occurence of c in A. |
| RankLessThan(c, pos) | Return the number of c' < c in A[0:pos]. |
| RankMoreThan(c, pos) | Return the number of c' > c in A[0:pos]. |
| FreqRange(min_c, max_c, beg_pos, end_pos) | Return the number of min_c <= c' < max_c in A[beg_pos:end_pos]. |
| MaxRange(beg_pos, end_pos) | Return the maximum value and its position in A[beg_pos:end_pos]. |
| MinRange(beg_pos, end_pos) | Return the minimum value and its position in A[beg_pos:end_pos]. |
| QuantileRange(beg_pos, end_pos, k) | Return the (k+1)-th smallest value and its position in A[beg_pos:end_pos]. |
| ListModeRange(min_c, max_c, beg_pos, end_pos, num) | Return the most frequent characters and its frequencies in A[beg_pos:end_pos] and min_c <= c < max_c. |
| ListMinRange(min_c, max_c, beg_pos, end_pos, num) | Return the characters in ascending order and its frequencies in A[beg_pos:end_pos] and min_c <= c < max_c. |
| ListMaxRange(min_c, max_c, beg_pos, end_pos, num) | Return the characters in descending order and its frequencies in A[beg_pos:end_pos] and min_c <= c < max_c. |
| dump(filename) | Save the current status to the file. |
| load(filename) | Load the status from the file. |
| dumps() | Return the current status as string. |
| load(string) | Load the status from the string. |
For MaxRange, MinRange, and QuantileRange, if there are many such positions, return the left most position. If an argument is invalid, these methods return watarray.NOTFOUND.
Note
The descriptions above are based on documents of wat-array.
Released under the MIT License.