Results for: "String#[]"

Returns the number of bits of the value of int.

“the number of bits” means that the bit position of the highest bit which is different to the sign bit. (The bit position of the bit 2**n is n+1.) If there is no such bit (zero or minus one), zero is returned.

I.e. This method returns ceil(log2(int < 0 ? -int : int+1)).

(-2**12-1).bit_length     #=> 13
(-2**12).bit_length       #=> 12
(-2**12+1).bit_length     #=> 12
-0x101.bit_length         #=> 9
-0x100.bit_length         #=> 8
-0xff.bit_length          #=> 8
-2.bit_length             #=> 1
-1.bit_length             #=> 0
0.bit_length              #=> 0
1.bit_length              #=> 1
0xff.bit_length           #=> 8
0x100.bit_length          #=> 9
(2**12-1).bit_length      #=> 12
(2**12).bit_length        #=> 13
(2**12+1).bit_length      #=> 13

This method can be used to detect overflow in Array#pack as follows.

if n.bit_length < 32
  [n].pack("l") # no overflow
else
  raise "overflow"
end

Private. Use Matrix#determinant

Returns the determinant of the matrix, using Bareiss’ multistep integer-preserving gaussian elimination. It has the same computational cost order O(n^3) as standard Gaussian elimination. Intermediate results are fraction free and of lower complexity. A matrix of Integers will have thus intermediate results that are also Integers, with smaller bignums (if any), while a matrix of Float will usually have intermediate results with better precision.

Returns the inner product of this vector with the other.

Vector[4,7].inner_product Vector[10,1]  => 47

Returns an angle with another vector. Result is within the [0…Math::PI].

Vector[1,0].angle_with(Vector[0,1])
# => Math::PI / 2

Returns the portion of the original string after the current match. Equivalent to the special variable $'.

m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie")
m.post_match   #=> ": The Movie"

Returns the factorization of value.

Parameters

value

An arbitrary integer.

generator

Optional. A pseudo-prime generator. generator.succ must return the next pseudo-prime number in the ascending order. It must generate all prime numbers, but may also generate non prime numbers too.

Exceptions

ZeroDivisionError

when value is zero.

Example

For an arbitrary integer:

n = p_1**e_1 * p_2**e_2 * .... * p_n**e_n,

prime_division(n) returns:

[[p_1, e_1], [p_2, e_2], ...., [p_n, e_n]].

Prime.prime_division(12) #=> [[2,2], [3,1]]

Returns the factorization of self.

See Prime#prime_division for more details.

Iterates the given block over all prime numbers.

See Prime#each for more details.

As int is already an Integer, all these methods simply return the receiver.

Synonyms are to_int, floor, ceil, truncate.

List of options that will be supplied to RDoc

Dup internal hash.

Clone internal hash.

Sets the system path (the Shell instance’s PATH environment variable).

path should be an array of directory name strings.

Specifies the threads that this object will wait for, but does not actually wait.

Specifies the threads that this object will wait for, but does not actually wait.