IBM 15 Manuale Utente
140
Chapter 8
Function
Result
Description
cdf_normal(NUM, MEAN,
STDDEV)
STDDEV)
Real
Returns the probability that a value from the normal
distribution with the specified mean and standard
distribution with the specified mean and standard
deviation will be less than the specified number.
cdf_t(NUM, DF)
Real
Returns the probability that a value from Student’s t
distribution with the specified degrees of freedom will
distribution with the specified degrees of freedom will
be less than the specified number.
Bitwise Integer Operations
These functions enable integers to be manipulated as bit patterns representing two’s-complement
values, where bit position
values, where bit position
N has weight 2**N. Bits are numbered from 0 upward. These operations
act as though the sign bit of an integer is extended indefinitely to the left. Thus, everywhere above
its most significant bit, a positive integer has 0 bits and a negative integer has 1 bit.
its most significant bit, a positive integer has 0 bits and a negative integer has 1 bit.
Note: Bitwise functions cannot be called from scripts.
Function
Result
Description
~~ INT1
Integer
Produces the bitwise complement of the integer INT1.
That is, there is a 1 in the result for each bit position for
which INT1 has 0. It is always true that
That is, there is a 1 in the result for each bit position for
which INT1 has 0. It is always true that
~~ INT = –(INT
+ 1). Note that this function cannot be called from a
script.
script.
INT1 || INT2
Integer
The result of this operation is the bitwise “inclusive or”
of INT1 and INT2. That is, there is a 1 in the result for
each bit position for which there is a 1 in either INT1
or INT2 or both.
of INT1 and INT2. That is, there is a 1 in the result for
each bit position for which there is a 1 in either INT1
or INT2 or both.
INT1 ||/& INT2
Integer
The result of this operation is the bitwise “exclusive
or” of INT1 and INT2. That is, there is a 1 in the result
for each bit position for which there is a 1 in either
INT1 or INT2 but not in both.
or” of INT1 and INT2. That is, there is a 1 in the result
for each bit position for which there is a 1 in either
INT1 or INT2 but not in both.
INT1 && INT2
Integer
Produces the bitwise “and” of the integers INT1 and
INT2. That is, there is a 1 in the result for each bit
position for which there is a 1 in both INT1 and INT2.
INT2. That is, there is a 1 in the result for each bit
position for which there is a 1 in both INT1 and INT2.
INT1 &&~~ INT2
Integer
Produces the bitwise “and” of INT1and the bitwise
complement of INT2. That is, there is a 1 in the result
for each bit position for which there is a 1 in INT1 and
a 0 in INT2. This is the same as
complement of INT2. That is, there is a 1 in the result
for each bit position for which there is a 1 in INT1 and
a 0 in INT2. This is the same as
INT1&& (~~INT2) and
is useful for clearing bits of INT1 set in INT2.
INT << N
Integer
Produces the bit pattern of INT1 shifted left by N
positions. A negative value for N produces a right shift.
positions. A negative value for N produces a right shift.
INT >> N
Integer
Produces the bit pattern of INT1 shifted right by N
positions. A negative value for N produces a left shift.
positions. A negative value for N produces a left shift.
INT1 &&=_0 INT2
Boolean
Equivalent to the Boolean expression
INT1 && INT2
/== 0 but is more efficient.
INT1 &&/=_0 INT2
Boolean
Equivalent to the Boolean expression
INT1 && INT2
== 0 but is more efficient.