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