Re: Re: Re: How to find which variable caused

*To*: mathgroup at smc.vnet.net*Subject*: [mg103903] Re: [mg103879] Re: [mg103821] Re: How to find which variable caused*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Mon, 12 Oct 2009 06:36:00 -0400 (EDT)*References*: <20091011164313.476926@jfultz2winlap>*Reply-to*: drmajorbob at yahoo.com

Right you are. My bad. Bobby On Sun, 11 Oct 2009 16:43:13 -0500, John Fultz <jfultz at wolfram.com> wrote: > I was quite explicit about this in my previous email... > >>> * Use separate Dynamics, which display inside a Row[] as empty strings > > I.e., the Row is scoping two empty strings and the Text[]. Replacing > Row with > Column makes empty space because empty strings take up a full line > height in a > Column. The controls come from the surrounding Manipulate, and so > nothing > inside the Row is displaying as a column. > > Sincerely, > > John Fultz > jfultz at wolfram.com > User Interface Group > Wolfram Research, Inc. > > > On Sun, 11 Oct 2009 14:30:22 -0500, DrMajorBob wrote: >> Why does that Row display as a column? (Even when I stretch the window >> over two monitors.) >> >> Replacing Row with Column gives the same result, except that there's a >> lot >> of excess space in the Text box... even when I specify 0 as the 3rd >> argument, as in >> >> Manipulate[ >> Column[{Dynamic[ >> Refresh[xFlag = True; yFlag = False; "", TrackedSymbols -> {x}]], >> Dynamic[Refresh[xFlag = False; yFlag = True; "", >> TrackedSymbols -> {y}]], >> Dynamic[Text[ >> StringJoin["you moved the ", Which[xFlag, "x", yFlag, "y"], >> " slider"]]]}, Left, 0], {x, 0, 1}, {y, 0, 1}, {{xFlag, False}, >> ControlType -> None}, {{yFlag, False}, ControlType -> None}] >> >> Why is that? >> >> Bobby >> >> On Sat, 10 Oct 2009 06:09:45 -0500, John Fultz <jfultz at wolfram.com> >> wrote: >> >>> This is a very simple version of what you asked for that doesn't solve >>> some of >>> the fundamental problems you'll probably come across, but it shows you >>> the >>> techniques to solving them. Principally... >>> >>> * Contain all evaluation inside of scoped Dynamics to prevent the >>> entire >>> Manipulate from refreshing. >>> * Add flag variables (and perhaps you'll want other variables, too) as >>> control >>> variables, but with ControlType->None so they don't appear. >>> * Use separate Dynamics, which display inside a Row[] as empty strings >>> (this is >>> important...remember that if a Dynamic doesn't display onscreen, then >>> there's >>> nothing available to update...see my previous posts on Dynamic if >>> you're >>> at all >>> confused about this), to track the individual variables. >>> + These separate Dynamics each scope a single variable only. >>> + The scoped variable is determined by using Refresh with >>> TrackedSymbols >>> >>> One of the problems my version doesn't solve is sensibly setting a >>> start >>> condition, so the evaluation assumes that the initial state has changed >>> the y >>> parameter (as a result of the initial creation of the flag-tracking >>> dynamics). >>> That's a problem I'll let you figure out. >>> >>> >>> Manipulate[Row[{ >>> Dynamic[ >>> Refresh[xFlag = True; yFlag = False; "", TrackedSymbols -> {x}]], >>> Dynamic[ >>> Refresh[xFlag = False; yFlag = True; "", TrackedSymbols -> {y}]], >>> Dynamic[ >>> Text[StringJoin["you moved the ", Which[xFlag, "x", yFlag, "y"], >>> " slider"]]] >>> }], >>> {x, 0, 1}, {y, 0, 1}, >>> {{xFlag, False}, ControlType -> None}, >>> {{yFlag, False}, ControlType -> None}] >>> >>> >>> Sincerely, >>> John Fultz >>> jfultz at wolfram.com >>> User Interface Group >>> Wolfram Research, Inc. >>> >>> >>> On Thu, 8 Oct 2009 07:49:43 -0400 (EDT), Nasser Abbasi wrote: >>> >>>> >>>> "Nasser Abbasi" <nma at 12000.org> wrote in message >>>> news:hafbgr$j4r$1 at smc.vnet.net... >>>> >>>>>> Again, I want something like this >>>>>> >>>>>> Manipulate[ >>>>>> process[( pickTheCorrectControlVariableWhichChanged ], >>>>>> {a, 0, 1}, {b, 0, 1}, Initialization :> >>>>>> >>>>>> (process[arg_] := Module[{}, Plot[Sin[arg*x], {x, -Pi, Pi}]]) >>>>>> ] >>>>>> >>>> >>>>> I made some progress and I think I have a solution. >>>>> >>>>> I save the old value of each control variable in a global variable, >>>>> then >>>>> in >>>>> the Manipulate expression, I check, using an If statement which >>>>> current >>>>> value of the control variable is different from the old value. I >>>>> got it >>>>> to >>>>> work ok finally. >>>>> >>>>> Here is an example: >>>>> >>>>> olda = 999; >>>>> oldb = 999; >>>>> >>>>> Manipulate[ >>>>> If[olda != a, {olda = a; Style[StringJoin["a=", ToString[a]]]}, >>>>> >>>>> If[oldb != b, {oldb = b; Style[StringJoin["b=", ToString[b]]]}, >>>>> >>>>> Text["this message should NOT show up!"]]], {a, 0, 1}, {b, 0, 1}, >>>>> >>>>> LocalizeVariables -> True, TrackedSymbols -> {a, b}] >>>>> >>>>> >>>> It is me again, with the same problem. >>>> >>>> I found out that I can NOT use global variables in a demo, and I also >>>> can't >>>> wrap the whole Manipulate inside a module. Any one of the above method >>>> will >>>> have solved this problem, but rules are rules, so now I have to find >>>> another >>>> solution. So I am stuck again. >>>> >>>> Before I recode everything again, which I would hate to do, I thought= >>> I'll >>>> ask one more time, may be some expert can have a solution. But this >>>> one= >>> is >>>> really hard. >>>> >>>> I'll explain again the problem to make sure we are all clear on it. >>>> >>>> I need to write a Manipulate where inside the Manipulate I need to >>>> detect >>>> which slider or in other words, which control variable was changed. >>>> i.e. >>>> which slider the user just changed to cause the Manipulate expression >>>> to >>>> be >>>> generated. (I need to do this so I can do different processing based >>>> on >>>> the >>>> slider that was selected) >>>> >>>> We all know that Manipulate generates a new version of its expression= >>> when >>>> one of the control variables changes value. I need to know which >>>> control >>>> variable changed. >>>> >>>> There is the general layout >>>> >>>> Manipulate[ >>>> >>>> (* expression that uses control variables *) >>>> >>>> , >>>> >>>> (* controls here which update the control variables values *) >>>> ] >>>> >>>> But there are restriction on the solution, since this will be for a >>>> demo. >>>> Again, there can NOT be global variables used, (i.e. no variables in >>>> the >>>> Manipulate initialization section, since these are global), and there >>>> can >>>> NOT be a module around Manipulate[], i.e. no Module[{...}, >>>> Manipulate[...]] >>>> allowed. >>>> >>>> Here is a small code to show the problem >>>> >>>> Manipulate[ >>>> Text[StringJoin["you moved the ", "x or y", " slider"]], >>>> {x, 0, 1}, >>>> {y, 0, 1} >>>> ] >>>> >>>> Could someone modify the above, so that the code above will tell which >>>> slider the user _just_ moved? >>>> >>>> It seems like an impossible problem for me to solve without the use of >>>> global variables or a module around Manipulate. >>>> >>>> Here is what I tried so far, and this fail: >>>> >>>> Manipulate[ >>>> Which[ >>>> >>>> x != oldx, >>>> {oldx = x; Text[StringJoin["you moved the ", "x ", " slider"]]}, >>>> >>>> y != oldy, >>>> {oldy = y; Text[StringJoin["you moved the ", "y ", " slider"]]}, >>>> >>>> True, Text["why Ami here??"] >>>> ], >>>> >>>> {x, 0, 1}, >>>> {y, 0, 1}, >>>> {oldx, -999, ControlType -> None}, >>>> {oldy, -999, ControlType -> None} >>>> ] >>>> >>>> The reason it fail is because oldx and oldy are updated to the same >>>> value >>>> of >>>> x and y whenever x or y changes before I get the chance to do the >>>> comparison. I.e. when the new version of the expression is generated, >>>> oldx=x >>>> and oldy=y each time. This seems to consequences of Manipulate= >>> generating >>>> DynamicModule[] for the whole thing. You can see this by using the >>>> SnapShot >>>> option on the Manipulate output. This will generate the whole >>>> expression >>>> form. (Nice tool). >>>> >>>> If someone can make it so that the above will display the correct >>>> message >>>> each time, then I would declare that person to be the Mathematica Guru >>>> of >>>> the year. >>>> >>>> I think I have reached the limit of my current Mathematica >>>> understanding >>>> when it comes to internals of Manipulate and Dynamics to be to solve >>>> this >>>> one. But I'll keep on looking. >>>> >>>> Thank you, >>>> --Nasser > > > -- DrMajorBob at yahoo.com