Browse and cite Stata manuals easily: The wwwhelp command

Abstract

In this article, we describe a new command, wwwhelp, that facilitates direct access to online versions of Stata’s official help files or PDF documentation. Addressing the challenges associated with storing, citing, and sharing documentation, wwwhelp complements the help command by enabling access to documentation outside the Stata environment. In addition to fully using the abundant resources available on Stata’s website, wwwhelp enhances the convenience of citing Stata commands in articles and blog posts, thereby promoting the utilization and dissemination of Stata commands.

1 Introduction

Retrieving Stata’s learning materials is crucial to the proficiency of Stata users and the continued development of the software. Users can browse help files offline and click on links for more detailed PDF documentation with the help command. However, the offline help files can be read and used only within Stata, and the offline PDF documentation, ¹ which can also be accessed outside Stata, is too big to pinpoint and disseminate specific commands quickly and accurately. Fortunately, alternative versions of documentation for each official command are provided on Stata’s website, including online help files and corresponding online PDF documentation, which are easier to navigate and share. The help files offer brief overviews of the official commands, while the PDF documentation provides more detailed explanations, such as Remarks and examples sections. ² Below are links to good examples of an online help file and an online PDF documentation entry:

Help file: https://www.stata.com/help.cgi?regress

PDF documentation: https://www.stata.com/manuals/rregress.pdf

We developed a command, wwwhelp, that enables more convenient access to these resources outside Stata’s environment. In addition, with options such as texfull or markdown, the wwwhelp command can display citations and links to online help files or PDF documentation in Stata’s Results window that can be easily copied to the clipboard or documents in various formats such as .tex or .md. For advanced users aiming to share Stata knowledge in articles or blog posts, wwwhelp is particularly convenient for referencing Stata commands and providing links to relevant pages for readers’ convenience, which enables readers without Stata installed or without a computer at hand to understand the detailed functions of Stata commands. For example, Gould (2010) wrote

You can read the online help or the manual about the Mata function luinv(). I chose it because I needed a matrix inverter that could handle nonsymmetric matrices.

Users can type wwwhelp mata luinv, texfull to get the link and citation pasted into the clipboard automatically as

which turns out to be the following readable text after being pasted into a .tex file and then compiled.

You can read the online help or the manual about the Mata function [M-5] mata luinv . I chose it because I needed a matrix inverter that could handle nonsymmetric matrices.

For more detailed information, see section 2.3.

The remainder of the article is organized as follows. Section 2 introduces the usage of the wwwhelp command. Section 3 concludes. For more details of the conceptual framework and programming challenges, please see the appendix.

2 Syntax and usage

2.1 Syntax

2.2 Common use

wwwhelp is used to open the online help files and PDF documentation of Stata’s official commands. Specifically, the documents that can be opened directly using the help command can also be opened online using the wwwhelp command, including both detailed PDF versions and simple help versions. By default, wwwhelp opens the online PDF version, which contains detailed descriptions and explanations of a specific command. When the web option is specified, the online help version will be opened so that users can quickly look at the basic information of commands. For example, one can type the following command:

It will open a 30-page PDF version of the documentation that details how to use the xtreg command. The document is opened through the browser and can be easily downloaded, cited, and shared.

Figure 1.

Open PDF documentation via wwwhelp

Now we add the web option.

This command will open a simple online help file that concisely describes the syntax of xtreg and offers a brief introduction of uses and functions of the command. The online help files are small and useful supplements to the PDF documentation, facilitating dissemination and reference. Furthermore, we have written hhelp, a simpler command based on wwwhelp that allows faster access to the online help versions without any options. So wwwhelp xtreg, web is equivalent to hhelp xtreg.

Figure 2.

Open online help file via wwwhelp with option web or hhelp

2.3 Citing with various formats

To enhance the convenience of citation, the wwwhelp command has incorporated various formatting options, including markdown, txt, ms, latex, texfull, and format(), and has enabled users to access web links to the online documentation in their desired format. Notably, the text will be automatically copied to the clipboard; users can disable this automatic copying function with the clipoff option if they wish. For more information, refer to the online appendix. In this section, we will introduce the referencing feature of wwwhelp through specific scenarios and provide a detailed explanation of formatting options.

In practice, there are numerous scenarios in which a Stata command might be referenced. For example, references in the Stata Blog are frequently seen but seldom hyperlinked to online help files or PDF documentation, as shown in the following excerpt from Balov (2022):

Quarterly observations on real GDP, measured in billions of dollars, are obtained from the Federal Reserve Economic Data repository using the import fred command. I consider observations only between the first quarter of 1947 and second quarter of 2021. A quarterly date variable, dateq , is generated and used with tsset to set up the time series.

References in the Stata Journal also lack hyperlinks to online help files or PDF documentation, as shown in the following excerpt from Cox (2022):

One more step in technique yields many useful results. The step is to use generate and egen (see [D] generate and [D] egen ) as workhorses within a framework provided by the by (see [D] by ) prefix. The perspective is now that new variables are needed, so that we can graph, table, and further analyze our results most easily.

In other resources, such as Stata manuals and textbooks, referencing Stata commands is also necessary. However, the lack of hyperlinks prevents users from accessing related information independently of Stata.

With wwwhelp, Stata commands can be hyperlinked to the corresponding online help files or PDF documentation, which allows users to obtain detailed information about the commands by simply clicking on the links instead of switching to Stata and searching in the Command window. The wwwhelp command provides several hyperlink formatting options that are designed to accommodate the different syntax requirements of various editors. For example, the texfull and markdown options generate link text that is suitable for L^AT_EX and Markdown syntax, respectively. In the following sections, we will provide a detailed introduction to the usage of the markdown, txt, ms, latex, texfull, and format() formatting options. In addition, every option has a corresponding abbreviation, such as m for markdown. For details, see help wwwhelp.

markdown displays the web link in Markdown format:

The text is automatically copied to the clipboard and appears as a clickable link when pasted into Markdown. It looks like this: [R] regress . Notably, on macOS, the note will say … Press ‘Command+V’ to paste, while on Windows it will say … Press ‘Ctrl+V’ to paste.

txt displays the web link as text:

It can be copied to the dialog box of Facebook or WeChat for Chinese users.

ms sends rich text punctuated with links to the clipboard, which can be pasted easily to Microsoft Word:

When users press Ctrl+V in Microsoft Word, the text will appear as a clickable link. It looks like this: [R] regress . However, this option has some limitations. It requires Stata 16 or newer versions of Stata to be installed. It also requires Python because the commands call the Windows API through Stata’s interaction with Python, and it is currently available only for Windows systems. Otherwise, it will automatically switch to the txt option, which displays plain text with links as shown above.

texfull displays the web link as full T_EX text:

It can be inserted into a .tex document, which will appear as a clickable link in the PDF file when compiled using a T_EX editor. It looks like this: [R] regress .

latex displays the web link in L^AT_EX form:

It can be inserted into a .tex document, which will appear as a clickable link in the PDF file when compiled using a L^AT_EX editor. It looks like this: [R] regress .

Note that because \stwwwhelp is a new user-defined command in the .tex document, it must be defined by adding the following code to the introductory section of the .tex file:

format( # ) displays the web link in three supporting Markdown preset formats.

format(1) is rendered in Markdown as [R] regress .

format(2) is rendered in Markdown as regress .

format(3) is rendered in Markdown as help regress .

Below are examples of format(1)–format(3):

All the above are web links to the online PDF documentation. wwwhelp can also provide web links to the online help files if you specify the web option:

2.4 Special cases

There are some special cases in using the wwwhelp command, including the following:

Multiple keywords

Some help files require multiple keywords to be uniquely identified. The basic syntax structure is category+keyword, such as the graph class (wwwhelp graph export), the Mata class (wwwhelp mata intro), and the function class (wwwhelp math function, wwwhelp string function). For more complicated cases, we recommend using the help command to find out the correct keywords at the first step and then using the wwwhelp command to get their online help files. More specifically, we can find the target document by searching some keywords with the help command, clicking on the relevant hint links, copying the complete command (for example, help datetime functions) from the address bar of the Viewer window, and then pasting it into the Stata Command window. If you add the prefix www to the retrieved command, the resulting wwwhelp datetime functions command can be executed to access the online version.

Sections

For long documents, users can usually locate a particular section in the document using the command help command## Section, where Section refers to the specific subsection of interest and the ## symbol serves as a locator. For example, help regress postestimation##estatvif will open the help file for the regress postestimation command and automatically navigate to the location of estatvif. However, because the naming of the subsection bookmarks in the PDF documentation is not systematic, subsection positioning through wwwhelp might not be exact. For example, when a user enters wwwhelp regress postestimation##estatvif, Stata will open the online PDF documentation for regress postestimation but will not locate the estatvif section accurately.

Command abbreviations

wwwhelp also supports command abbreviations. For uniquely identified command abbreviations, wwwhelp will open the corresponding online help file or PDF documentation directly. For example, wwwhelp reg is equivalent to wwwhelp regress, which will open an online PDF version of documentation for the regress command. If a command abbreviation does not uniquely identify the official command, wwwhelp will provide advice and list several similar commands using the abbreviation as a keyword for users to choose from. For example,

3 Conclusions

This article introduced wwwhelp, which enables direct access to Stata’s online documentation, including both detailed PDF versions and simple help versions. It also incorporates various formatting options, enabling users to access web links to the online documentation in their desired format, which will be automatically copied to the clipboard. In brief, just add a “www” before “help”, and you can enjoy Stata’s powerful and desirable help.

wwwhelp can access only online help files or PDF documentation. We hope that future research can further use other online resources, such as the Stata Journal and StataCorp’s website, so that users can easily retrieve and browse all Stata resources online.

5 Programs and supplemental material

Supplemental Material, sj-zip-1-stj-10.1177_1536867X241233676 - Browse and cite Stata manuals easily: The wwwhelp command

Supplemental Material, sj-zip-1-stj-10.1177_1536867X241233676 for Browse and cite Stata manuals easily: The wwwhelp command by Yongli Chen and Yujun Lian in The Stata Journal