7.7.3. IDX of Integers
|
(lsh/libidx/idx-int.lsh) |
Basic operations on vectors, matrices, and tensors of integers.
7.7.3.0. (idx-i1addc m1 c m2)
|
(lsh/libidx/idx-int.lsh) |
Add constant to idx1 of int.
7.7.3.1. (idx-i2addc m1 c m2)
|
(lsh/libidx/idx-int.lsh) |
Add constant to idx2 of int.
7.7.3.2. (idx-i1concat int-vec1 int-vec2 ...)
|
(lsh/libidx/idx-int.lsh) |
Concatenate the int-vectors in
argument list and return new big vector.
7.7.3.3. (random-permute perm-vector)
|
(lsh/libidx/idx-int.lsh) |
randomly permute the elements of the given
permutation-vector (an integer vector)
7.7.3.4. (multinomial-sample probabilities)
|
(lsh/libidx/idx-int.lsh) |
Given a vector of probabilities of
length N summing to one for events 0 to N-1, return an integer i
associated to these events with probability
probabilities [i]. The algorithm samples a uniform number
between 0 and 1 and loops through the
probabilities vector, so its running time is O(N).
N.B.: if the sum S of the elements is 1, then
the value N-1 will be sampled more frequently with extra probability 1 -
S. if the sum S of the elements is 1, then only the first M
elements will be sampled, with M being such that it is the largest
integer such that the sum of the probabilities
from 0 to M-1 is above 1.
7.7.3.5. (fast-multinomial-sample cumulative-probabilities)
|
(lsh/libidx/idx-int.lsh) |
Given a vector of cumulative-probabilities
of length N, monotonically increasing between 0 and 1, return an integer
between 0 and N-1 sampled from the corresponding distribution. The
algorithm samples a uniform number between 0 and 1 and does a binary
search in the cumulative probabilities, so its running time O(log(N))
whereas the running time of (multinomial-sample
probabilities ) is O(N). For this call to be really fast, the
computation of cumulative-probabilities
from probabilities must be done ahead
of time (because it takes O(N) time). It can be done with
(distribution2cumulative probabilities
cumulative-probabilities ).
See: (multinomial-sample probabilities
)
See: (distribution2cumulative
probabilities cumulative-probabilities
)
7.7.3.6. (distribution2cumulative probabilities cumulative-probabilities)
|
(lsh/libidx/idx-int.lsh) |
Fill cumulative-probabilities by
putting at the i-th position the sum the numbers in
probabilities from the beginning to the (i-1)-th position.
Therefore, cp[0]=0 and cp[N-1] may be 1. This is
P(value < i).
7.7.3.7. (element-in-set int-element int-set)
|
(lsh/libidx/idx-int.lsh) |
Return true iff int-element is in the
int-set vector.
7.7.3.8. (idx-i1max m)
|
(lsh/libidx/idx-int.lsh) |
returns largest element in m
7.7.3.9. (idx-i1min m)
|
(lsh/libidx/idx-int.lsh) |
same as idx-m1min for vectors of integers
7.7.3.10. (idx-i1fill-with-index m)
|
(lsh/libidx/idx-int.lsh) |
fill the elements of idx1 m with their
index.
7.7.3.11. (idx-i1fill m c)
|
(lsh/libidx/idx-int.lsh) |
((-idx1- (-int-)) m):
((-int-) c):
CREATED: P.Haffner, April 97
DESCRIPTION: Fills 1D int matrix with constant <c>
7.7.3.12. (idx-i2fill m c)
|
(lsh/libidx/idx-int.lsh) |
((-idx2- (-int-)) m)):
((-int-) c):
CREATED: P.Haffner, April 97
DESCRIPTION: Fills 2D int matrix with constant <c>