17.1 Exponents and Logarithms
- Mapping Function: exp (x)
Compute
e^x , now with MathML,
for each element of x.
To compute the matrix exponential, see Linear Algebra.
See also: log.
- Mapping Function: expm1 (x)
Compute
exp (x) - 1
accurately in the neighborhood of zero.
See also: exp.
- Mapping Function: log (x)
Compute the natural logarithm,
ln (x) ,
for each element of x.
To compute the matrix logarithm, see Linear Algebra.
See also: exp, log1p, log2, log10, logspace.
- Function File: reallog (x)
Return the real-valued natural logarithm of each element of x.
If any element results in a complex return value reallog aborts and
issues an error.
See also: log, realpow, realsqrt.
- Mapping Function: log1p (x)
Compute
log (1 + x)
accurately in the neighborhood of zero.
See also: log, exp, expm1.
- Mapping Function: log10 (x)
Compute the base-10 logarithm of each element of x.
See also: log, log2, logspace, exp.
- Mapping Function: log2 (x)
- Mapping Function: [f, e] = log2 (x)
Compute the base-2 logarithm of each element of x.
If called with two output arguments, split x into
binary mantissa and exponent so that
1/2 <= abs(f) < 1
and e is an integer. If
x = 0 , f = e = 0 .
See also: pow2, log, log10, exp.
- Function File: pow2 (x)
- Function File: pow2 (f, e)
With one input argument, compute
2 .^ x
for each element of x.
With two input arguments, return
f .* (2 .^ e).
See also: log2, nextpow2, power.
- Function File: nextpow2 (x)
Compute the exponent for the smallest power of two larger than the input.
For each element in the input array x, return the first integer
n such that
2^n ≥ abs (x).
See also: pow2, log2.
- Function File: realpow (x, y)
Compute the real-valued, element-by-element power operator.
This is equivalent to x .^ y , except that
realpow reports an error if any return value is complex.
See also: power, reallog, realsqrt.
- Mapping Function: sqrt (x)
Compute the square root of each element of x.
If x is negative, a complex result is returned.
To compute the matrix square root, see Linear Algebra.
See also: realsqrt, nthroot.
- Function File: realsqrt (x)
Return the real-valued square root of each element of x.
If any element results in a complex return value realsqrt aborts and
issues an error.
See also: sqrt, realpow, reallog.
- Mapping Function: cbrt (x)
Compute the real cube root of each element of x.
Unlike x^(1/3) , the result will be negative if x is
negative.
See also: nthroot.
- Function File: nthroot (x, n)
-
Compute the real (non-complex) n-th root of x.
x must have all real entries and n must be a scalar.
If n is an even integer and x has negative entries then
nthroot aborts and issues an error.
Example:
nthroot (-1, 3)
⇒ -1
(-1) ^ (1 / 3)
⇒ 0.50000 - 0.86603i
See also: realsqrt, sqrt, cbrt.
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