R語言seq()函數(shù)的調(diào)用方法

更新時間：2021年03月11日 10:23:37 作者：Running Mars

這篇文章主要介紹了R語言seq()函數(shù)的調(diào)用方法,本文給大家介紹的非常詳細，對大家的學(xué)習(xí)或工作具有一定的參考借鑒價值，需要的朋友可以參考下

看到有很多讀者瀏覽了這篇文章，心里很是開心，為了能夠更好地幫助大家，決定再修改一下，幫助大家更好地理解。

--------修改于：2018年4月28日

為了方便大家在開發(fā)環(huán)境中直接實驗測試代碼，下面，我將說明和函數(shù)的用法全部用英文給出（避免亂碼），并加以注釋，希望能夠?qū)Υ蠹矣兴鶐椭?/p>

首先，我們來看一個seq()函數(shù)應(yīng)用的實例！

x <- seq(0, 10, by = 0.01)
y <- sin(x)
plot(y)

下面，我們來看函數(shù)的主要使用方法！

注意：在本文調(diào)用函數(shù)時，均采用寫出入口參數(shù)名的方法，比如：

seq(from = 1, to = 2)

這樣函數(shù)的調(diào)用更加清晰，在調(diào)用較多函數(shù)時，不會發(fā)生混亂和參數(shù)匹配錯誤。

方式一：seq(from, to)

from：生成向量的起點，to：生成向量的終點，默認步長為1（可修改）

a <- seq(from = 1, to = 2)
# [1, 2]

方式二：seq(from, to, by = )

by：向量元素之間的步長

a <- seq(from = 1, to = 3, by = 0.5)
# [1, 1.5, 2, 2.5, 3]

方式三：seq(from, to, length.out = )

length.out：向量中元素數(shù)目

a <- seq(from = 1, to = 3, length.out = 5)
# [1, 1.5, 2, 2.5, 3]

方式四：seq(along.with = )

along.with：表示生成的向量為現(xiàn)有一向量元素的索引

x <- c(1.2, 5.2, 6.3, 4.6)
a <- seq(along.with = x)
# [1, 2, 3, 4]

方式五：seq(from)

該方式和方式四功能相似

x <- c(1.2, 5.2, 6.3, 4.6)
a <- seq(from = x)
# [1, 2, 3, 4]

方式6：seq(length.out = )

生成從1開始，步長為1，長度為length.out的向量

a <- seq(length.out = 5)
# [1, 2, 3, 4, 5]

上述幾種方式為較為常見的方式，詳細的函數(shù)說明如下：

Sequence Generation

Description

Generate regular sequences. seq is a standard generic with a default method. seq.int is a primitive which can be much faster but has a few restrictions. seq_along and seq_len are very fast primitives for two common cases.

---------------------------------------------

Usage

seq(...)
## Default S3 method:
seq(from = 1, to = 1, by = ((to - from)/(length.out - 1)),
length.out = NULL, along.with = NULL, ...)
seq.int(from, to, by, length.out, along.with, ...)
seq_along(along.with)

seq_len(length.out)

---------------------------------------------

Arguments

1：...

arguments passed to or from methods.

2：from, to

the starting and (maximal) end values of the sequence. Of length 1 unless just from is supplied as an unnamed argument.

3：by

number: increment of the sequence.

4：length.out

desired length of the sequence. A non-negative number, which for seq and seq.int will be rounded up if fractional.

5：along.with