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1

As Oleksandr pointed out as well, you may not be able to use your constraint as stated. Your alternative expressed as an inequality should actually be quite function, if you can calculate the eigenvalues of your target matrix symbolically in a reasonable time. You first obtain a symbolic expression for your eigenvalues, by running Eigenvalues once only, and ...

2

Wrap your Monitor call in a Function object endowed with a holding attribute: Table[Pause[n/10], {n, 10}] // Function[{input}, Monitor[input, n], HoldAll] This will work as though you had wrapped Monitor around your Table.

2

You can use Unevaluated Unevaluated@Table[Pause[n/10], {n, 5}] // Monitor[#, n] & The neater way will be to use the infix version as suggested by wxffles in the comments, but your question specifically asked for postfix so... For completeness, here it is Table[Pause[n/10], {n, 5}] ~Monitor~ n

0

I fixed the issue by utilizing the "Cubics" and "Quartics" options for eigensystem. The code runs much quicker and the manipulates are smoother. There is no more eigenvalues jumping around. Before the output of the eigensystem was a bunch of "root" expressions which I believe remained unevaluted until the plot functions. Now that the expressions are expanded ...

5

Clarification of HoldPattern usage: HoldPattern[expr] is equivalent to expr for pattern matching, but maintains expr in an unevaluated form. I think this can be ambigious for begginers. One could think that what we are doing in MatchQ[HoldPattern[a[1]], HoldPattern[_[_]]] is to more or less MatchQ[ a[1], _[_] ] where both arguments are kept ...

4

The following is an expansion of the explanation given by Mr.Wizard. The pattern-matcher works on the base of the assumption that Orderless attribute is already applied and the arguments of the Orderless function are already sorted in the canonical order: ClearAll[o] SetAttributes[o, Orderless] MatchQ[Hold[o[y, x, a]], Hold[o[_, x, a]]] (* unsorted ...

4

UPDATE That question is by the essence an exact duplicate of this one. The explanation given by Mr.Wizard means that the pattern-matcher is NOT capable to handle situations when an unevaluated function with Orderless attribute is wrapped by Hold. So this is indeed a gedanken functionality. The pattern-matcher works on the base of the assumption that ...

3

You can put a Verbatim on the Plus: MatchQ[Hold[x + 2 y + 0], Hold[Verbatim[Plus][x, 2 _, 0]]] (* True *) Another way: expr = Inactivate[x + 2 y + 1]; form = Inactivate[x + 2 _ + 1]; MatchQ[expr, IgnoringInactive@form] (* True *)

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