Short version of question
In recent versions of Matlab (I have seen it in R2014b and R2015a on Windows), when you type help foo you get a brief description of the function and its signatures. For example, typing help bsxfun produces something like this (only with better format):
This MATLAB function applies the element-by-element binary operation specified by the function handle fun to arrays A and B, with singleton expansion enabled.
C = bsxfun(fun,A,B)
Reference page for bsxfun
See also arrayfun, repmat
Other uses of bsxfun
distcomp/bsxfun
This is of course only a summary of the actual documentation. To get the full documentation you need to type doc foo. This opens the HTML help browser, which takes quite some time (at least on some computers).
Is there a way to get the full help in the command window (thus avoiding the help browser), as it used to be in older Matlab versions?
Long version of question
To look into this in more detail, I'll define "old" Matlab versions as those that don't have HTML help, and "new" versions as those that do. I also need to give each type of help a name, in order to refer to them:
FP (Full, Plain): full help in the form of plain text, shown in Matlab command window (old style).
SH (Summarized, HTML): summarized help in the form of HTML, shown in Matlab command window.
FH (Full, HTML): full help in the form of HTML, shown in the help browser.
As is well known, the text for FP help is contained in the first comment lines in the file defining the function. In new Matlab versions, functions may also have an associated HTML file. This file contains SH help in an HTML tag, and FH help in HTML code.
Possible behaviour is:
In old Matlab versions, help foo produced FP help.
In new Matlab versions, help foo produces SH help if foo has an associated HTML help file, and FP help if it doesn't.
In new Matlab versions, doc foo produces FH help if foo has an associated HTML help file. If it doesn't, FP help is shown in the help browser (without format).
So the problem is more properly phrased as: how to show FP help in new Matlab versions when foo has an associated HTML help file. The question is meaningful because
Most Matlab functions do have an associated HTML help file.
Most Matlab functions, even built-in functions (that have no m-code), have and m-file containing FP help.
An additional motivation is that in some cases the FP documentation contains features that don't appear in the FH documentation (see for example here).
Original answer (Matlab versions R2014b, R2015a)
Although the documentation doesn't tell, the help function in these Matlab versions supports zero, one or two output arguments. You can check this typing open help and looking at the function signature:
function [out, docTopic] = help(varargin)
In essence, help works internally as follows:
It creates an object called process, of class helpUtils.helpProcess, by calling the class constructor as:
process = helpUtils.helpProcess(nargout, nargin, varargin);
where nargout, argin and varargin are those with which help was called.
It runs the method process.getHelpText, which calls the undocumented, built-in function helpfunc, and as a result sets the property process.helpStr. This property contains the help string which is shown in the command window.
As it turns out, at least on Windows, depending on the value of nargout (which gets passed to the constructor helpUtils.helpProcess) the resulting help string will be FP or SH. Namely, it will be FP if nargout>0, and SH if nargout==0. You can check this by typing the following code (adapted from help.m) directly in the command window:
process = helpUtils.helpProcess(1, 1, {'bsxfun'});
process.getHelpText
process.helpStr
This will produce FP help. On the other hand, changing the first 1 (which corresponds to nargout in the actual call) into a 0,
process = helpUtils.helpProcess(0, 1, {'bsxfun'});
process.getHelpText
process.helpStr
will produce SH help.
I don't know why this is so, that is, how it works on a deeper level than this. All I know is that the getHelp method calls the undocumented helpfunc, which is at least involved in producing FP help.
So, to get FP help you need to call help with one or two output arguments. For example,
str = help('foo')
assigns the FP help text to variable str and displays it. Or you can use
disp(help('foo'))
which also has the effect of calling help with an (implicit) output argument.
To have this behaviour from the standard command help foo, you could define a help function to override Matlab's help, and place it in your Matlab document folder. This folder normally appears first in the path (or you can make sure it does by editing startup.m), and thus has precedence. The new function will essentially call Matlab's help with one output argument, and then display the resulting (FP) help text. In order to call the overriden function it is necessary to temporarily change to its folder:
function help(varargin)
if isempty(varargin)
varargin = {'help'}; %// `help` should be equivalent to `help help`
end
d = pwd; %// take note of current folder
cd(fullfile(matlabroot, 'toolbox', 'matlab', 'helptools')) %// folder where the
%// standard `help` function is
disp(help(varargin{1}));
cd(d) %// restore folder
So now, finally, help foo produces the old-style (FP) help.
Edit for Matlab version R2015b
In Matlab R2015b the behaviour seems to have changed for the better. Typing help foo no longer produces SH help. It's not exactly FP either. In fact it's better than that: it produces FH help but in the command Window, not in the browser. Or, equivalently, it produces FP help but with links and better formattting.
So no need to tweak anymore!
Edit for Matlab version R2018a
Matlab R2018a again gives SH help. The solution provided in this answer works (that is, produces FP help).
So back to tweaking!
A better way is to include the full path to the function when using the help command, then old style full help is displayed and the links also work, e.g. try:
help surf
help(fullfile(matlabroot, 'toolbox', 'matlab', 'graph3d', 'surf.m'))
I’ve just submitted an override help function based on this to MATLAB FEX:Full Command Line Help
I try to create a snippet which needs a little elisp code (about 15 lines). I don't want to put all the code there to make the snippet looks very ugly. A function call is the best choice. But I am not sure where should I put the code for that function.
For example: (Ugly)
${1: $(supper long elisp code here)}
I expect something like:
${1: $(my-function arg)}
Then where should I put my-function code?
You can place the code in your initialization file. The function just needs to be defined before call yas-expand.
(Edited to include followup from comments.)
You can also create a .yas-snippet.el file in the same directory as the snippet with your function (example).
When using the Matlab interface I can access the help for a function by using help function
or by pressing F1 while the cursor is on the function name.
Is it possible to access the Matlab help files from within Vim? An other possibility may be to convert Matlab function help to a Vim helpfile and use :help function
I found that font-lock-add-keywords is the key but I cannot find how to add a pattern. For example, in clojure;
(defn a-function-name [argument vector]
...)
a-function-name is highlighted becuase it's after defn and before [argument vector]. How can I write a rule for this?
(font-lock-add-keywords 'lisp-mode XXXXX)
I cannot write XXXXX part for myself.
=======================
Thank you to all of you :-) Yes, I can find clue in docs and clojure-mode.el as of you said.
Here is what I do and it works well (at least for me)
(font-lock-add-keywords
'lisp-mode
'(("(\\(#defn\\)\\>[ \r\t\n]*\\(\\sw+\\)+\\>?"
(2 'font-lock-function-name-face))))
Why I need this is that I define some macros and emacs does not highlight them properly.
Type C-h f font-lock-add-keywords. In the help for that function, there will be a link for font-lock-keywords, where the format for what you call XXXXXX is described.
If with that help you are still having trouble, post your attempt to achieve what you want so you can receive more specific help regarding your problem.
To add to what #juanleon said: See the Elisp manual, node Search-Based Fontification for information about font-lock-keywords. That will help you "write the XXXXX part for yourself."
Then, as #juanleon said, try something and ask for more help here if it doesn't work. Code tried gets help.
I wrote a Lisp function earlier that had an error. The first challenge was to figure out how to view the function again. That challenge is solved. Now that I see WHAT I have done wrong, I want to modify the contents of the defined function without rewriting the whole thing?
Seems like as intelligent as Lisp is, there HAS to be a way to do this, I just don't know what it is because I am fairly new to the language. Can this be done?
Judging from the question, I think that you have a strange setup. It seems to indicate that you are writing your functions directly at the REPL. Don't do that.
The usual setup is to have an IDE (for example, Emacs with Slime) where you edit a source file, and then "send" top-level forms (like function definitions) to the REPL.
Every useful REPL has a history functionality. It allows you to move in the history of your input backwards and forwards.
When I write code in the REPL simple keystrokes like m-p gets back earlier code. Some IDEs might even be able to locate source code in a Lisp listener with m-. .
In most REPLS you can also search incrementally backwards.
If you want a log of your input use the function DRIBBLE..
There are some more options, like retrieving the code from the function - when a Lisp IDE supports that.
There is the advice functionality in many Lisps, which lets you run additional code before or after or around an existing function. But the comment is right, why wouldn't you rewrite a function if you're still learning and trying things out? Do they charge you by the compile cycle?