Dependent Manipulate sliders

Question

I would like to use dependent sliders in Manipulate. First slider K0 should be independent and varied from Kmin to Kmax. Two others sliders K1 and K2 should dependend on K0 so that K1*K2 == K0 should be always true. Is it possible?

Answer 1

As always, here is the more customizable DynamicModule version:

DynamicModule[{k0, k1, k2, kMin = -1, kMax = 1},
 Panel[Grid[{
   {"k0", Slider[Dynamic[k0, (k0 = #; k2 = k0/k1) &], {kMin, kMax}], Dynamic@k0},
   {"k1", Slider[Dynamic[k1, (k1 = #; k2 = k0/k1) &], {-1, 1}, Exclusions -> {0}], Dynamic@k1},
   {"k2", Slider[Dynamic[k2, (k2 = #; k1 = k0/k2) &], {-1, 1}, Exclusions -> {0}], Dynamic@k2},
   {Panel[Dynamic@Grid[{
         {"k0", k0}, {"k1", k1}, {"k2", k2}, {"k1*k2", k1*k2}}, 
        Alignment -> Left], ImageSize -> {250, 90}], SpanFromLeft}
   }, Alignment -> Left], ImageSize -> {300, 200}]
 ]

Note that division by zero is handled by Exclusions -> {0}.

Answer 2

Here's one thing you might try

 k0Old = 1; k1Old = 1; k2Old = 1; kMin = 1; kMax = 2;
 Manipulate[
   If[k1 != k1Old || k0 != k0Old, k2 = k0/k1; k1Old = k1; k0 = k0Old];
   If[k2 != k2Old, k1 = k0/k2; k2Old = k2;];
      {k0, k1, k2, k1 k2}, {k0, kMin, kMax}, {k1, 0.1, 10}, {k2, 0.1, 10}]