Coupled controls in a Manipulate expression

Question

I have a paragraph

Manipulate[
    expr,
    { {a, 1}, 1, 4, 1},
    { {b, 2}, 2, 5, 1}
]

and I want variable b to be bigger than a at all times.

I have searched for help on this and one thread on this site mentions the functions Manipulate and Dynamic, but as I am new to Mathematica I don't fully understand the solution - and as I won't need Mathematica too much in the future it's not expedient for me to read through 5 page tutorials on both functions until I maybe get how both work.

Thanks in advance

Does this or linked topics answer your question?: Interdependent controls in Manipulate — Kuba, Nov 26 '16 at 19:33
Manipulate[a + b, {{a, 1}, 1, 4, 1}, {b, a + 1, a + 6, 1}] — Alan, Nov 26 '16 at 20:14

score 2 · Answer 1 · answered Nov 28 '16 at 03:11

2

You can assign dependencies between the Manipulate variables. For example:

Manipulate[If[b < a, {a, b} = {Min[a, b], Max[a, b]}]; {a, b}, 
          {{a, 1}, 1, 4}, {{b, 2}, 2, 5}]

answered Nov 28 '16 at 03:11

bill s

68,936
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score 0 · Answer 2 · edited Apr 13 '17 at 12:55

0

Extending the comment by Alan with a TrackingFunction to ensure that also the value of b is increased whenever necessary:

Manipulate[a + b,
 {{a, 1}, 1, 4, 1, TrackingFunction -> (a = #; If[b <= a, b = a + 1]; &)},
 {b, a + 1, a + 6, 1}]

edited Apr 13 '17 at 12:55

Community

1

answered Dec 11 '16 at 10:24

Karsten7

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Coupled controls in a Manipulate expression

2 Answers2