Re: [Matplotlib-users] Placing a marker at specific places where lines join?

[Wayne W. <sie...@sb...>]

Well, I'm not quite sure what to say to your claim. In certain instances 
I am trying to get through to someone here that something is missing for 
newbies. In one word, pedagogy (as perhaps in a text book, not a 
reference manual or dictionary). I'm trying to be positive about it, and 
not negative. Positive criticism I hope. I apologize if I offend you.

Note the post of my to-do list here a few days ago.  Clearly I have a 
number of things to do to better understand what is going on, and I plan 
to do them. Every item was gleaned from this mailing list. Everyone. I 
have the 868 page pdf that that someone mentioned (It is perhaps the 
best source here, but is very long for newbies.), and I have searched it 
for clues on how to proceed in this instance. I have seen references to 
marker in the document, set_marker, edge, etc. I've looked through the 
doc you suggested in the link. I have looked at a good number or 
examples on various questions I have about matplotlib to see their 
applicability. Examples are not necessarily education.  I'm not sure you 
really understand my question.

I see examples on  how to produce markers at every join of lines.That's 
really easy. I do not see how to put a single marker on the plot. Not 
one at each join.  I'll draw you a picture and attach it. The attachment 
consists of maybe 100 joined lines.
They are so short that they look like a straight line in many cases. 
Nevertheless,I'd like to mark the joins in such a way that suggests 
meaningful points. These lines represent a path. Sometimes it dodges 
away from the main path a good distance, or may go backwards*.  At the 
start I'd like to put a marker (perhaps green), 90 points away I'd like 
to put another marker, and finally at the end  another marker (perhaps 
red).  The image I produced doesn't not exactly produce this, but the 
point is four markers, and not 100.  Is it possible to do that? A friend 
of mine tells me that in MatLab that it is.

* Yes, I read about plot display navigation in the big 868 page file. 
This will  have  a  good payoff to the users of the program I'm working 
on. The developer put an MPL plot in it, and no description of the plot 
navigation.



On 2/13/2010 6:55 PM, John Hunter wrote:
> On Sat, Feb 13, 2010 at 8:03 PM, Wayne Watson
> <sie...@sb...>  wrote:
>    
>> Suppose I plot a line from (0,0) to (1,1.5) to (2,2). Now I want to mark

-- 
"Crime is way down. War is declining. And that's far from the good 
news." -- Steven Pinker (and other sources) Why is this true, but yet 
the media says otherwise? The media knows very well how to manipulate us 
(see limbic, emotion, $$). -- WTW