Help function does not work

When I try to open the help window, it displays "An error occurred displaying helpwin content".

[Nikhilesh]

Please drop a few more details, like version name and if possible the error mesaage. And we can discuss it further.

You can also refer to the following discussion help does not work - MATLAB Answers - MATLAB Central (mathworks.com)

[至韬]

The version is R2022b, and error message is as follows when i type something randomly (e.g. 'save'):

com.mathworks.jmi.MatlabException: the input should be either a char-array or a cell-array with chars

at com.mathworks.jmi.NativeMatlab.SendMatlabMessage(Native Method)

at com.mathworks.jmi.NativeMatlab.sendMatlabMessage(NativeMatlab.java:273)

at com.mathworks.jmi.MatlabLooper.sendMatlabMessage(MatlabLooper.java:120)

at com.mathworks.jmi.Matlab.mtFeval(Matlab.java:1732)

at com.mathworks.mde.help.DisplayDocPageWorker.runOnMatlabThread(DisplayDocPageWorker.java:19)

at com.mathworks.jmi.MatlabWorker$2.run(MatlabWorker.java:79)

Answer 1

[Pratheek]

Hi,

Help is a basic functionality in MATLAB these are some of the reasons for which help function fails to work:

1. There may be a conflict with other software installed on your computer. Try disabling any antivirus or firewall software temporarily to see if it resolves the issue.
2. The MATLAB help files may be stored in a network drive that is not currently accessible. If you are using MATLAB in a network environment, make sure that you are connected to the network and that the network drive where the help files are stored is accessible.
3. There may be a problem with the MATLAB installation or configuration. Try resetting the MATLAB preferences to their default values by typing matlab -prefs reset in the Command Window and restarting MATLAB.
4. The help content files may be missing or corrupted. In this case, you may need to reinstall MATLAB to restore the missing or corrupted files.

It is easy to help if you share some information regarding whcih version of MATLAB you are working on and for what command you got this error.

There are different ways to use the help command in MATLAB. Here are some of the most common ones:

1. To get help on a specific function, type help function_name in the Command Window, where function_name is the name of the function you want help with. For example, to get help on the sin function, type help sin.
2. You can also use the doc command to get more detailed help on a function. Type doc function_name in the Command Window, where function_name is the name of the function you want help with. For example, to get detailed help on the sin function, type doc sin.
3. If you don't know the exact name of a function, you can use the help command with a keyword. Type help keyword in the Command Window, where keyword is the keyword you want to search for. For example, to get a list of functions related to trigonometry, type help trigonometry.
4. Finally, you can use the MATLAB Help Browser to search for help topics. Click on the Help menu in the MATLAB Desktop, and select Help Browser. This will open the MATLAB Help Browser, where you can search for help topics by keyword or browse through the contents.

[至韬]

Thanks a lot for your reply!

I met trouble when using help command before, and it seems that i can use it now. Here's the wrong message:

>> help conv

警告: 执行 'matlab.internal.help.helpProcess' 类析构函数时，捕获到以下错误:

错误使用 contains

the input should be either a char-array or a cell-array with chars

出错 matlab.internal.help.makeDualCommand (第 11 行)

if contains(command,'.') || any(contains(string(varargin), invalidDualArgumentPattern))

出错 matlab.internal.help.helpProcess/displayHelp (第 18 行)

searchMessage =

getString(message('MATLAB:helpUtils:displayHelp:SearchMessageWithLinks',

erase(matlab.internal.help.makeDualCommand('docsearch', hp.topic), '"')));

出错 matlab.internal.help.helpProcess/delete (第 104 行)

disp(hp.displayHelp);

出错 help (第 31 行)

end

> 位置：help (第 31 行)

[至韬]

And i also met similar trouble before, the wrong message is as follows:

>> doc conv

错误使用 ismember

第二个参数 必须为文本。

出错 split (第 60 行)

sep = ismember(str, delimiter);

出错 matlab.internal.doc.url.DocContentPage/splitPath (第 139 行)

pathParts = split(pathParts,"/"|"\")';

出错 matlab.internal.doc.url.DocContentPage/set.RelativePath (第 52 行)

splitPath = matlab.internal.doc.url.DocContentPage.splitPath(value);

出错 matlab.internal.doc.reference.getReferencePage>getReferenceItemDocPage (第 129 行)

docPage.RelativePath = refItem.Href;

出错 matlab.internal.doc.reference.getReferencePage>findReferencePage (第 76 行)

docPage = getReferenceItemDocPage(refItems(1));

出错 matlab.internal.doc.reference.getReferencePage (第 22 行)

[docPage, refTopics, primitive] = findReferencePage(topic, isVariable);

出错 doc (第 57 行)

[docPage, displayText, primitive] = matlab.internal.doc.reference.getReferencePage(topics);

[至韬]

And i may try to restall matlab again. I met the same trouble when using R2022a and i've already restalled once. But still thanks for your suggestions!

Answer 2

[Image Analyst]

Sounds like an installation problem. See the FAQ:

https://matlab.fandom.com/wiki/FAQ#After_installation,_MATLAB_crashes_or_gives_an_error_message_when_I_try_to_run_MATLAB.