[instaviz-users] Recog 1.0.2

[Glen Low]

Juan, All

On 05/10/2008, at 6:12 PM, Juan Antonio Navarro Pérez wrote:

> * When you purposefully draw incoherent shapes, or just random
> strokes, shapes tend to be accepted as ellipse or diamond. I don't
> know what should be better, perhaps to let the user know that the
> shape was not recognized as a valid shape?

I experimented with a version that returned "unknown" when the  
probability is below a certain threshold, but Recog became more fussy  
about getting the shapes right. On the balance of things I'll have to  
see how it goes with the flow of the final Instaviz app -- it might be  
easier to cancel out of a wrongly recognized shape than deal with the  
occasional dialog box asking for a confirmation and/or frustrating the  
user with no shape being drawn.
>
>
> * I'm guessing that the most popular shapes will be squares and
> circles. When I try to draw them, most of the times they're recognized
> appropriately, but there are a few cases in which they end up being
> recognized as rectangle or ellipse. Would it be a good idea to skew
> the recognizer so that it tends to detect mostly squares and circles,
> and only detect a rectangle/ellipse if the shape is really thin?

Actually according to the few Graphviz stats I've been gathering, the  
most popular shape is the ellipse, which is the default shape in any  
case. I'd suspect ellipses and rectangles are more popular since you  
can put more text into them.
>
>
> * Finally, I've found an interesting "bug" in the recognizer. When you
> draw a square with the following strokes: down, right, up, left, down
> (i.e. the last/first side is drawn twice), then the square tends to be
> recognized as an ellipse. I'm guessing ellipses tend to have more
> overlapping when drawing than squares. Anyway, I don't know how much
> people would draw a "double side" like that in real life. (I know I
> didn't when providing data with the previous Guesstur app).

Hmm... the recognizer tends to be thrown off when you use more strokes  
than the shape in question (e.g. doubling strokes or overlapping  
strokes), and also if you use less strokes (e.g. drawing an incomplete  
rectangle). Does this bother any of you?




Cheers, Glen Low


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