Re: clunky fn plots

[<pl...@pi...>]

On 10/11/11 20:25, Juhász Péter wrote:
> On Tue, 2011-10-11 at 19:49 +0200, pl...@pi... wrote:
>> On 10/11/11 19:21, sfeam (Ethan Merritt) wrote:
>>> On Tuesday, 11 October 2011, pl...@pi... wrote:
>>>> On 10/11/11 18:42, sfeam (Ethan Merritt) wrote:
>>>>> On Tuesday, 11 October 2011, pl...@pi... wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I was under the impression that plotting functions and data in the same
>>>>>> plot command meant the interval for the fn plot would follow the
>>>>>> datafile.
>>>>>
>>>>> The sample interval for function plots is controlled only by the
>>>>> "set sample" and "set isosample" commands.   There is no connection to
>>>>> the number or location of points in any of the data plots.
>>>>>
>>>>> 	Ethan
>>>>>
>>>>
>>>> Many thanks Ethan .
>>>>
>>>> in fact my college had just discovered that setting via wgnuplot's menus
>>>> . It would have taken me a lot longer on linux digging blindly thought
>>>> the help.
>>>
>>> Then the most useful thing might be for you to suggest where in the help
>>> system to add this information.  Where did you look first?  Would that be
>>> a logical place to add mention of "set sample"?
>>
>> Well , I think that is half (most of ) the discovery problem. Why would
>> I think of looking for sample or set sample without already know the answer?
>>
>> This term is presumably short for sample rate, but when a _user_ is
>> thinking of plotting a function he will not consider that he is
>> "sampling".  The term does not evoke what it does.
>>
>> "help function" is very terse and does not deal directly with plotting
>> functions nor does it direct you to that sort of info with a "see also".
>>
>> "help plot" does not even have a subtopic about functions.
>>
>> help plot>  ranges does not cover it either, though there would be some
>> logical reason to look there.
>>
>> Indeed , could this actually be set as a extension to the range specifier ?
>>
>>
>> Any , or perhaps all those places could be used to at least point the
>> user with a "see also" comment.
>>
>> I hope those suggestions are useful.
>>
>> best.
>>
>
> An idea I've just had:
> perhaps it would be worth introducing a feature like "man -k" in *nix
> or ?? in R.
>
> If the user were looking for the way to do something but didn't know
> where he should look, he could use a hypothetical new "searchhelp" or
> "helpindex" command with some keyword related to his troubles, and
> gnuplot would list the relevant help topics.
>
>
> By the way, an answer to your original question would be
>
> plot "datafile" using 1:2, "" using 1:(f($1))
>
> which would evaluate your function at exactly the same points as the
> datafile.
>
> Péter Juhász
>
>

Ah , thank you very much. That , to me would seem to be a logical 
default if the fn is in that same command as the data.

set sample is sufficient if it is findable, but I prefer this solution.

Hopefully it can be a bit more visible as a result of this thread.

Thanks for that tip.

regards. Peter.