itemcoding.html

来自「本程序是基于linux系统下c++代码」· HTML 代码 · 共 150 行

HTML
150 行
字号 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>R: Item Coding &ndash; Handling Item Labels and Column IDs Conversions</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link rel="stylesheet" type="text/css" href="../../R.css">
</head><body>

<table width="100%" summary="page for itemCoding {arules}"><tr><td>itemCoding {arules}</td><td align="right">R Documentation</td></tr></table>
<h2>Item Coding &ndash; Handling Item Labels and Column IDs Conversions</h2>


<h3>Description</h3>

<p>
Provides the generic functions and the S4 methods for converting item labels
into column IDs used in the binary matrix representation and vice versa.
</p>
<p>
<code>decode</code> converts from the numeric (column IDs) representation to
readable item labels.  <code>decode</code> is used by <code><a href="LIST.html">LIST</a></code>.
</p>
<p>
<code>encode</code> converts from readable item labels to an itemMatrix using a
given coding. With this method it is possible to create several compatible
<code>itemMatrix</code> objects (i.e., use the same binary representation for
items) from data. 
</p>
<p>
<code>recode</code> recodes an <code>itemMatrix</code> object so its coding is compatible
with another object.
</p>


<h3>Usage</h3>

<pre>
decode(x, ...)
## S4 method for signature 'list':
decode(x, itemLabels)
## S4 method for signature 'numeric':
decode(x, itemLabels)

encode(x, ...)
## S4 method for signature 'list':
encode(x, itemLabels, itemMatrix = TRUE)
## S4 method for signature 'character':
encode(x, itemLabels, itemMatrix = TRUE)
## S4 method for signature 'numeric':
encode(x, itemLabels, itemMatrix = TRUE)

recode(x, ...)
## S4 method for signature 'itemMatrix':
recode(x, itemLabels = NULL, match = NULL)
</pre>


<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>x</code></td>
<td>
a vector or a list of vectors of character strings 
(for <code>encode</code>) or of numeric (for <code>decode</code>), or
an object of class <code>itemMatrix</code> (for <code>recode</code>).</td></tr>
<tr valign="top"><td><code>itemLabels</code></td>
<td>
a vector of character strings used for coding where 
the position of an item label in the vector gives the item's column ID.  
The used <code>itemLabels</code> vector can be obtained from <code>itemMatrix</code>,  
<code>transactions</code> and <code>associations</code> by the 
method <code>itemLabels</code>.</td></tr>
<tr valign="top"><td><code>itemMatrix</code></td>
<td>
return an object of class <code>itemMatrix</code> otherwise
an object of the same class as <code>x</code> is returned.</td></tr>
<tr valign="top"><td><code>match</code></td>
<td>
an <code>itemMatrix</code> object whose item coding <code>x</code> 
should match.</td></tr>
<tr valign="top"><td><code>...</code></td>
<td>
further arguments.</td></tr>
</table>

<h3>Value</h3>

<p>
<code>recode</code> always returns an object
of class <code>itemMatrix</code>.
<br>
For <code>encode</code> with <code>itemMatrix = TRUE</code> an object
of class <code>itemMatrix</code> is returned.
Otherwise the result is of the same type as <code>x</code>, e.g., a
list or a vector.</p>

<h3>See Also</h3>

<p>
<code><a href="LIST.html">LIST</a></code>,
<code><a href="associations-class.html">associations-class</a></code>,
<code><a href="itemMatrix-class.html">itemMatrix-class</a></code>
</p>


<h3>Examples</h3>

<pre>
data("Adult")

## Example 1: Manual decoding
## get code
iLabels &lt;- itemLabels(Adult)
head(iLabels)

## get undecoded list and decode in a second step
list &lt;- LIST(Adult[1:5], decode = FALSE)
list

decode(list, itemLabels = iLabels)

## Example 2: Manually create an itemMatrix 
data &lt;- list(
    c("income=small", "age=Young"),
    c("income=large", "age=Middle-aged")
    )

iM &lt;- encode(data, iLabels)
iM

inspect(iM)

## use the itemMatrix to create transactions
as(iM, "transactions")

## Example 3: use recode
## select first 100 transactions and all education-related items
sub &lt;- Adult[1:100, itemInfo(Adult)$variables ==  "education"]
itemLabels(sub)
image(sub)

## recode to match Adult again
sub.recoded &lt;- recode(sub, match = Adult)
image(sub.recoded)
</pre>



<hr><div align="center">[Package <em>arules</em> version 0.6-6 <a href="00Index.html">Index]</a></div>

</body></html>

itemcoding.html - 源码说明

本页面展示了「本程序是基于linux系统下c++代码」中的 itemcoding.html 源码文件，采用 HTML 编程语言编写，共 150 行代码。您可以在线阅读完整代码内容，也可以返回资源详情页下载完整源码包进行本地学习和开发。

虫虫下载站收录了大量与linux相关的技术资源，包括源代码、技术文档、电路图等，是电子工程师和嵌入式开发者的专业学习平台。

⌨️ 快捷键说明

复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?