R语言格式化数字和字符串format函数

数字和字符串可以使用 format()函数的格式化为特定样式。

语法

format()函数的基本语法是：

format(x, digits, nsmall,scientific,width,justify = c("left", "right", "centre", "none"))     

以下是所使用的参数的说明：

• x - 为向量输入
• digits - 是显示总位数
• nsmall - 是最小位数的小数点右边
• scientific - 设置为TRUE，则显示科学记数法
• width - 指示要通过填充空白在开始时显示的最小宽度
• justify - 是字符串显示在左边，右边或中心

示例

# Total number of digits displayed. Last digit rounded off.
result <- format(23.123456789, digits = 9)
print(result)

# Display numbers in scientific notation.
result <- format(c(6, 13.14521), scientific = TRUE)
print(result)

# The minimum number of digits to the right of the decimal point.
result <- format(23.47, nsmall = 5)
print(result)

# Format treats everything as a string.
result <- format(6)
print(result)

# Numbers are padded with blank in the beginning for width.
result <- format(13.7, width = 6)
print(result)

# Left justify strings.
result <- format("Hello",width = 8, justify = "l")
print(result)

# Justfy string with center.
result <- format("Hello",width = 8, justify = "c")
print(result)

当我们上面的代码执行时，它产生以下结果：

[1] "23.1234568"
[1] "6.000000e+00" "1.314521e+01"
[1] "23.47000"
[1] "6"
[1] "  13.7"
[1] "Hello   "
[1] " Hello  "

原文：http://www.cnblogs.com/csguo/p/7294080.html