Matlab基本函数-log函数

1、log函数：求自然对数

2、用法说明

      y = log(x) 函数对数组x的元素逐个进行以e为底的对数运算。y = a+b*i，有log(y) = log(abs(y))+i*atan2(b,a)

3、举例说明

>> x = 10

x =

    10

>> y = log(x)

y =

    2.3026

>> x = 1:10

x =

     1     2     3     4     5     6     7     8     9    10

>> y = log(x)

y =

         0    0.6931    1.0986    1.3863    1.6094    1.7918    1.9459    2.0794    2.1972    2.3026

>> x = [34-45i 12+23i 56+78i 26.12-45.89i]

x =

  34.0000 -45.0000i  12.0000 +23.0000i  56.0000 +78.0000i  26.1200 -45.8900i

>> y = log(x)

y =

   4.0325 - 0.9237i   3.2559 + 1.0899i   4.5646 + 0.9481i   3.9666 - 1.0533i

4、附录

>> help log
 log    Natural logarithm.
    log(X) is the natural logarithm of the elements of X.
    Complex results are produced if X is not positive.
 
    See also log1p, log2, log10, exp, logm, reallog.

    Overloaded methods:
       codistributed/log
       gpuArray/log
       fints/log
       designdev/log

    Reference page in Help browser
       doc log