在 R 编程中执行对数计算 - log()、log10()、log1p() 和 log2() 函数

R 语言中的log()函数返回参数中传递的参数的自然对数（以 e 为底的对数）。

Syntax: log(x)

Parameter:
x: Specified value.

Returns: It returns the natural logarithm of the specified value, infinity for 0 and NaN for the negative value.

示例 1：

# R program to calculate log value 
print(log(1)) 
print(log(30)) 
print(log(0)) 
print(log(-44)) 

输出：

[1] 0
[1] 3.401197
[1] -Inf
[1] NaN
Warning message:
In log(-44) : NaNs produced

对数（x，基数 = y）

log(x,base=y)是 R 中的一个内置函数，用于计算以 y 为底的指定值的对数，0 为无穷大，负值为 NaN。

Syntax: log(x, base = y)

Parameters:
x and base y.

Returns: It returns the logarithm of the specified value to base y, infinity for 0, and NaN for the negative value.

示例 2：

# R program to calculate log value 
print(log(10,base=10)) 
print(log(16,base=2)) 
print(log(0,base=10)) 
print(log(-44,base=4)) 

输出：

[1] 1
[1] 4
[1] -Inf
[1] NaN
Warning message:
In print(log(-44, base = 4)) : NaNs produced

log10()函数

log10()是 R 中的一个内置函数，用于计算以 10 为底的指定值的对数，0 为无穷大，负值为 NaN。

Syntax: log10(x)

Parameters:
x: Specified values.

Returns: It returns the logarithm of the specified value to base 10,infinity for 0 and NaN for negative value.

示例 2：

# R program to calculate log value 
print(log10(1)) 
print(log10(10)) 
print(log10(0)) 
print(log10(-44)) 

输出：

[1] 0
[1] 1
[1] -Inf
[1] NaN
Warning message:
In print(log10(-44)) : NaNs produced

log1p()

log1p()是 R 中的一个内置函数，用于计算 1+x 的准确自然对数，其中 x 是指定值，对于 0 抛出无穷大，对于负值抛出 NaN。

Syntax: log1p(x)

Parameters:
x: Specified values.

Returns: It returns the accurate natural logarithm of 1+x, where x is the specified value and throws infinity for 0 and NaN for negative value.

例子：

# R program to illustrate 
# the use of log1p() method
  
# Getting the accurate natural 
# logarithm of 1 + x, where x is 
# the specified value and throws 
# infinity for 0 and NaN for negative value.
print(log1p(1))
print(log1p(10))
print(log1p(0))
print(log1p(-44))

输出：

[1] 0.6931472
[1] 2.397895
[1] 0
[1] NaN
Warning message:
In log1p(-44) : NaNs produced

日志2（）

log2()是 R 中的一个内置函数，用于计算 x 以 2 为底的对数，其中 x 是指定值，或者对于 0 抛出无穷大，对于负值抛出 NaN。

Syntax: log2(x)

Parameters:
x: Specified values.

Returns: It returns the logarithm of x to base 2, where x is the specified value or throws infinity for 0 and NaN for negative value.

例子：

# R program to illustrate 
# the use of log2() method
  
# Getting the logarithm of x 
# to base 2, where x is the 
# specified value or throws 
# infinity for 0 and NaN for negative value.
print(log2(1))
print(log2(2))
print(log2(0))
print(log2(-44))

输出：

[1] 0
[1] 1
[1] -Inf
[1] NaN
Warning message:
In print(log2(-44)) : NaNs produced