Skip to main content

dynamic - Initializing Manipulator value within DialogInput (version 10.1 only)


Bug introduced in 10.1.0 and fixed in 10.2.0


I've confirmed, with WRI, that an issue was introduced in version 10.1 with regard to initializing Manipulator Dynamic values when the Manipulator is wrapped in a DialogInput.



Here, I'm asking for help in creating a work-around. The slightly modified code snippets I've included are from a larger notebook. But, they show the issue.


The following code shows the initialization of the Manipulator when not wrapped within a DialogInput:


DynamicModule[{val = 75.0},
  Print[val]; (* Print for Debug *)
  Column[{Manipulator[Dynamic[val], {50, 100, 0.2},
  Appearance -> {"Open", "Labeled"},

  AppearanceElements -> {"InputField", "StepLeftButton", "StepRightButton"}]}]
]

The above works fine with the Manipulator being initialized to 75., even in version 10.1.


The following is the code that will not propagate the initialization value to the Manipulator inside a DialogInput using version 10.1, but worked in prior versions. Note that the Manipulator is initialized to 50., not 75.:


DynamicModule[{val = 75.0},
  DialogInput[
    Print[val]; (* Print for Debug *)
    Column[{Manipulator[Dynamic[val], {50, 100, 0.2}, 
      Appearance -> {"Open", "Labeled"}, 

      AppearanceElements -> {"InputField", "StepLeftButton", "StepRightButton"}],
       Row[{DefaultButton[DialogReturn[{Today, Round[val, 0.2]}]], CancelButton[]}]}],
  WindowTitle -> "Input Value"]
]

In the actual code, the initialization value for val is from a file, not hard-coded. Can anyone think of a work-around that will allow me to get an initialization value into the Manipulator that works in version 10.1? It may not be possible, but I'm looking for something relatively simple that doesn't require modifying any system files.


To address some questions in the comments:


I should have mentioned that I'm running Win 8.1, 64-bit. Maybe it's specific to that OS version. I did get confirmation from WRI that they were able to reproduce my problem.


The purpose of the code is simply to be able to open a DialogInput with a slider initialized to a piece of data read from a file. If desired, manipulate the slider to a new value and return that value along with the date. If my current approach is not a good one, I'm open to better ideas.




Comments

Post a Comment

Popular posts from this blog

mathematical optimization - Minimizing using indices, error: Part::pkspec1: The expression cannot be used as a part specification

I want to use Minimize where the variables to minimize are indices pointing into an array. Here a MWE that hopefully shows what my problem is. vars = u@# & /@ Range[3]; cons = Flatten@ { Table[(u[j] != #) & /@ vars[[j + 1 ;; -1]], {j, 1, 3 - 1}], 1 vec1 = {1, 2, 3}; vec2 = {1, 2, 3}; Minimize[{Total@((vec1[[#]] - vec2[[u[#]]])^2 & /@ Range[1, 3]), cons}, vars, Integers] The error I get: Part::pkspec1: The expression u[1] cannot be used as a part specification. >> Answer Ok, it seems that one can get around Mathematica trying to evaluate vec2[[u[1]]] too early by using the function Indexed[vec2,u[1]] . The working MWE would then look like the following: vars = u@# & /@ Range[3]; cons = Flatten@{ Table[(u[j] != #) & /@ vars[[j + 1 ;; -1]], {j, 1, 3 - 1}], 1 vec1 = {1, 2, 3}; vec2 = {1, 2, 3}; NMinimize[ {Total@((vec1[[#]] - Indexed[vec2, u[#]])^2 & /@ R...
Post a Comment
Read more

functions - Get leading series expansion term?

Given a function f[x] , I would like to have a function leadingSeries that returns just the leading term in the series around x=0 . For example: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x)] x and leadingSeries[(1/x + 2 + (1 - 1/x^3)/4)/(4 + x)] -(1/(16 x^3)) Is there such a function in Mathematica? Or maybe one can implement it efficiently? EDIT I finally went with the following implementation, based on Carl Woll 's answer: lds[ex_,x_]:=( (ex/.x->(x+O[x]^2))/.SeriesData[U_,Z_,L_List,Mi_,Ma_,De_]:>SeriesData[U,Z,{L[[1]]},Mi,Mi+1,De]//Quiet//Normal) The advantage is, that this one also properly works with functions whose leading term is a constant: lds[Exp[x],x] 1 Answer Update 1 Updated to eliminate SeriesData and to not return additional terms Perhaps you could use: leadingSeries[expr_, x_] := Normal[expr /. x->(x+O[x]^2) /. a_List :> Take[a, 1]] Then for your examples: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x), x] leadingSeries[Exp[x], x] leadingSeries[(1/x + 2 + (1 - 1/x...
Post a Comment
Read more

What is and isn't a valid variable specification for Manipulate?

I have an expression whose terms have arguments (representing subscripts), like this: myExpr = A[0] + V[1,T] I would like to put it inside a Manipulate to see its value as I move around the parameters. (The goal is eventually to plot it wrt one of the variables inside.) However, Mathematica complains when I set V[1,T] as a manipulated variable: Manipulate[Evaluate[myExpr], {A[0], 0, 1}, {V[1, T], 0, 1}] (*Manipulate::vsform: Manipulate argument {V[1,T],0,1} does not have the correct form for a variable specification. >> *) As a workaround, if I get rid of the symbol T inside the argument, it works fine: Manipulate[ Evaluate[myExpr /. T -> 15], {A[0], 0, 1}, {V[1, 15], 0, 1}] Why this behavior? Can anyone point me to the documentation that says what counts as a valid variable? And is there a way to get Manpiulate to accept an expression with a symbolic argument as a variable? Investigations I've done so far: I tried using variableQ from this answer , but it says V[1...
Post a Comment
Read more