极客教程R语言 查找向量的和、平均数和乘积
在R语言中， sum(), mean(), 和 prod() 方法是可用的，用于计算方法中指定的参数上的指定操作。如果指定了一个单一的向量，那么操作将在单个元素上执行，这相当于应用for循环。
使用的函数
- mean()函数用于计算平均值。
语法： mean(x, na.rm)
参数
- x: 数值向量
- na.rm： 忽略NA值的布尔值
- sum() 用于计算总和
语法： sum(x)
参数
- x: 数值向量
- prod() 用来计算乘积
语法： prod(x)
参数
- x: 数值向量
下面的例子可以帮助你更好地理解。
例1 :
vec = c(1, 2, 3 , 4)
print("Sum of the vector:")
# inbuilt sum method
print(sum(vec))
# using inbuilt mean method
print("Mean of the vector:")
print(mean(vec))
# using inbuilt product method
print("Product of the vector:")
print(prod(vec))
输出
[1] “Sum of the vector:”
[1] 10
[1] “Mean of the vector:”
[1] 2.5
[1] “Product of the vector:”
[1] 24
例2 :
vec = c(1.1, 2, 3.0 )
print("Sum of the vector:")
# inbuilt sum method
print(sum(vec))
# using inbuilt mean method
print("Mean of the vector:")
print(mean(vec))
# using inbuilt product method
print("Product of the vector:")
print(prod(vec))
输出
[1] “Sum of the vector:”
[1] 6.1
[1] “Mean of the vector:”
[1] 2.033333
[1] “Product of the vector:”
[1] 6.6
例3： 有NaN值的向量
# declaring a vector
vec = c(1.1,NA, 2, 3.0,NA )
print("Sum of the vector:")
# inbuilt sum method
print(sum(vec))
# using inbuilt mean method
print("Mean of the vector with NaN values:")
# not ignoring NaN values
print(mean(vec))
# ignoring missing values
print("Mean of the vector without NaN values:")
print(mean(vec,na.rm = TRUE))
# using inbuilt product method
print("Product of the vector:")
print(prod(vec))
输出
[1] “Sum of the vector:”
[1] NA
[1] “Mean of the vector with NaN values:”
[1] NA
[1] “Mean of the vector without NaN values:”
[1] 2.033333
[1] “Product of the vector:”
[1] NA