Re: Keep Slider Consistent With a Slow Graph
- To: mathgroup at smc.vnet.net
- Subject: [mg100197] Re: Keep Slider Consistent With a Slow Graph
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Thu, 28 May 2009 04:26:17 -0400 (EDT)
- References: <gvdqtl$6q1$1@smc.vnet.net>
bobbaillie at frii.com wrote:
> The graph displayed by the Manipulate below takes a while to display.
> While the calculation is taking place, if you click on some other
> value on the slider, the slider moves and displays its new value.
> However, the graph will plot using the original value.
>
> The result is that the graph and the slider are now out of sync. This
> is bad user interface design.
>
> In the real example I am working with, there is no way to make the
> calculations go fast enough to keep up with clicks on the slider. For
> the same reason, I cannot allow the user to slide the slider, so
> ContinuousAction must be False.
>
> Nevertheless, is there some way to make sure the slider and the graph
> stay consistent with each other?
>
> Robert Baillie
>
> plotSlowGraph[xMax_] :=
> Module[
> { x, t },
> Plot[ NIntegrate[1/((t^2 - 1)*t*Log[t]),
> {t, x, Infinity}], {x, 2, xMax} ]
> ];
>
> Manipulate[
> Graphics[ plotSlowGraph[xMax] ],
> { {xMax, 10, "x Max"}, 10, 400, 10, Appearance -> "Labeled" },
> ContinuousAction -> False, SaveDefinitions->True
> ]
>
I would have thought that if you have a really slow process, a slider
just isn't a good way to manipulate it. Even with
ContinuousAction->False, you have the problem that merely releasing the
mouse will initiate a calculation at a value the user may not want.
Maybe you need a design in which the slider manipulates a number in an
InputField (which could obviously also be set directly) together with a
button that initiates a calculation.
David Bailey
http://www.dbaileyconsultancy.co.uk