Note that this relies on undocumented and unsupported functionality that may change in some future Matlab release.

This is not possible. The only exposed API’s is to use help to show the file help in the Command Window, or doc to show the documentation in the Help Browser.

I was wondering if there was a way to manually call the Help on Selection feature for a given function. Similar to how I can call doc(function) it would be nice if I could pop up the Help on Selection instead. My goal would be to have a GUI button execute this in a callback.

Good point about foo vs. tan. I hadn’t thought of that. I’m not sure what the best solution is. Your solution seems reasonable.

I agree with the bottom-most rule. But how would you propose distinguishing between

sin(foo F1

where “foo” is a mere variable, and generates no useful help, and

sin(tan F1

where “tan” does indeed generate useful help? I guess the rule there is, if there’s no help on it, move on down the line to the next item until you do find something with associated help. (So in the example above, if you press F1 at “sin(foo”, you get help on “sin”. If you have complete garbage, “foo(baz”, well, you probably don’t get anything.)

plot (sin ( F1

returns “doc sin” as expected, not “doc plot”.

Jared: yes, the “Avoid About” meta-rule would be great – thanks for adding that to the enhancement wish-list.

The rule should try to find the topmost unfinished function argument list or operator/expression, if possible. Maybe that’s too much to parse.

Thus

why F1
why( F1

would both pull up “doc why”, as they do now.

why(42 F1

right now pulls up the “About MATLAB” page, but since the open function is “why” it should pull up “doc why”. Maybe it should pull up http://www.hitchhikersmovie.com/ but that’s another story ;-).

why([42 ; F1

should not pull up “help why”, since the unfinished expression is the “[ ;” concatentation. It should pull up “doc vertcat” or “doc paren”. I’m not sure which it should do… maybe “doc vertcat”. Pick whichever makes for a simpler rule, I guess.

For the plot example:

plot (x, sin(x) F1

would pull up “doc plot” since sin(x) is a finished expression. But

plot (x, sin(x F1

would bring up “doc sin” as it does now.

As a fun aside, why(42) returns:
“To satisfy the tall and good not excessively terrified mathematician.”

Thanks,
Tim (a 6’2″ applied mathematician … I’ll let you fillin the rest…)

Jared

Showing operator help would be clever as well. I hadn’t thought about that. I’ll record these ideas as enhancement requests.

I just checked out how Visual Studio displays help for variable arguments.

They show a list of possible calls of the function. I was however not able to find a screenshot of this.

You could check the solution printfCS.sln as supplied with VS2005.

kind regards, Han