Questions about how Mathematica evaluates expressions, tracing evaluation (Trace*), handling expressions in unevaluated form (Hold*, Unevaluated), nonstandard evaluation, etc.

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2
votes
1answer
25 views

How can FoldList be used in postfix form?

As an exercise, I was trying to convert the following Clojure code to Mathematica: ...
5
votes
1answer
44 views

How to understand the different output of two UnsetShared?

Update From technical support, Thank you for contacting Wolfram Technical Support. I understand that you are reporting an issue with UnsetShared deleting the shared variable after a second ...
1
vote
1answer
19 views

Delete Cell Inside of Module

I want to print a dynamic output while some code is running and then automatically delete it when when the output is done. PrintTemporary is not quite what I am looking for -- I want the output to be ...
0
votes
0answers
43 views

Problem when extracting value from another function [closed]

I've created the following procedures to determine the pedal points of a point over polygons. ...
2
votes
3answers
106 views

Strong glitch with Evaluate in Manipulate

I'm experiencing a strong evaluation problem for a Manipulate box and I can't find the best solution yet. Here's a MWE to show the glitch : ...
1
vote
1answer
64 views

Help on order of evaluation within plot function

it is my first time asking a question here so please let me know if there's anything I should be doing that I'm unaware of. I'm sure the answer to my question already exists on the site but I'm having ...
3
votes
1answer
41 views

Difference between Initialization Cell and Group

Is there a difference between setting a Cell or a Group of cells to be an ...
0
votes
1answer
62 views

Function Evaluation in Table [closed]

Apologies in advance: this is a really basic question, and I am sure it has been answered, but I don't know enough mathematica to even find the answer. I have a differential equation I want to ...
1
vote
1answer
36 views

How do I run DialogInput and SystemDialogInput by keyboard shortcut?

I have tried modifying KeyEventTranslations.tr with code: ...
0
votes
1answer
27 views

Strange cell evaluation state

I have encountered a strange cell evaluation state (Shown in the image). It seems to be related with unknown variable a. What does this state means ? how it is different from simple error ?
2
votes
0answers
45 views

Optimization for iterating and plotting a matrix product and its elements?

I have an iterative matrix product of this type Since i didnt knew how to do it, I explicitly wrote the product as {Ayn + Bxn, Cyn + Dxn} and evaluated it with the NestList construct ...
1
vote
1answer
52 views

Calling functions defined inside Manipulate in other notebook?

I'm creating a notebook with a Manipulate and I'm trying to call/use a function from another notebook (I use Get for that), in ...
1
vote
0answers
49 views

Estimating processing time for commands

I am trying to evaluate some equations by using Taylor series of expansion (Series[], ExpandAll[], and Normal[] command), and using n equation and n unknown (Solve). Following is not full command (if ...
1
vote
2answers
75 views

Partial Function Evaluation [closed]

How can I evaluate only part of a stack of function calls? In particular, given f[x_,y_,z_]=x+y+z;, say, I'd like to define a function ...
1
vote
3answers
101 views

Multiple Plots inside a Manipulate with different dynamic variables on their x-axes

I have an expression with lots of variables, and I would like to make several plots of the expression, where the axis in each is a different variable. The idea is to put them side by side inside a ...
4
votes
1answer
57 views

Blocking dialog with a blocking child dialog

Suppose I have a DialogInput, in which there is a Button. The Button can trigger another ...
1
vote
1answer
37 views

Notebook Initialization

I am running Mathematica 10.2. I am having trouble automatically initializing a notebook. I realize that there have been several other questions/answers on this topic, but the advice given there ...
1
vote
1answer
60 views

How to force evaluation inside the body of a pure function?

For example, I'm writing a function to scale my list of numbers into a specific range. It goes like ...
-1
votes
1answer
57 views

How to plot a function, that is not properly defined in mathematica? [closed]

After rather long and relatively complicated calcuations, I finally got to a point where all my $x(t)$ functions are ...
6
votes
2answers
108 views

What is the Difference Between Rule (->) and RuleDelayed (:>)?

I am new to Mathematica so this question may seem rudimentary. Sorry for that! :) I want to implement the well-known property of Kronecker's Delta $$\Sigma_{i=1}^{n} a_i \delta_{ij}=a_j,\quad 1 \le ...
8
votes
3answers
175 views

Expand series unevaluated

I'm newbie in Mathematica. I'd like to obtain nice and verbose output for any series calculation. For example, given a simple sequence n*(-1)^(n-1) and ...
6
votes
0answers
64 views

Why Unevaluated doesn't work on unheld side of Rule/RuleDelayed?

Unevaluated is a function that I never truly understand, and here's one of the cases confusing me: ...
8
votes
1answer
145 views

Why one needs two Unevaluated to show 1+1 correctly in TreeForm?

The task sounds simple, give the tree plot of 1+1. However, after some trying, I can only make this possible by using two Unevaluated. ...
1
vote
1answer
57 views

Convert an evaluated in place code to original

I like "Evaluate In Place," because it hides code and works well. However, I can't figure out how to return to the original code when I want to modify it. I'm sure there is an easy way, but I can't ...
12
votes
3answers
449 views

Handling Kernel quit

One can use $Epilog to do something when the Kernel is quit or put an end.m file next to the ...
9
votes
0answers
64 views

Is there a way to TagSet a HoldAllComplete function?

Let's say I want to overload the built-in function Lookup, to handle my data wrapped in myObject. One would use ...
2
votes
1answer
59 views

Create a notebook and save it without prompting Dynamics

This is closely related to the recent: Creating self destructing notebook. However the answer doesn't work in my case. ...
8
votes
1answer
919 views

Creating self destructing notebook

Inspired by this post I've been trying to implement the idea in Wolfram with no success yet. I've come pretty close though and need some help. So I've managed to do this: ...
1
vote
0answers
103 views

Why this expression is not evaluated correctly?

Look at the following code: ...
4
votes
1answer
43 views

Partial evaluation of symbols with non-inert OwnValues

Background: there are many, many questions here about the infamous ::setraw error. More often, than not, they have to do with repeated assignments to symbols. Here's the code: ...
0
votes
1answer
42 views

Computing approximations of exponential [closed]

I have the code f[x_] := 13 x e^-x bit = Nest[f, 1, #] & /@ Prepend[1]@Range[4, 16, 4] Which I am using to compute values of $f^{(4)}(1), f^{(8)} (1), ...
1
vote
0answers
54 views

Evaluation of a Notebook

I am new to Mathematica so I do apologize if my question is too elementary. In the start of my notebook, I want to make sure that any previous definitions are wiped out so I use the ...
3
votes
1answer
92 views

Map works but Thread doesn't

This question may be trivial, but I can't get past it for the life of me. I have $n$ matrices of dimension $p_i \times N_i$, with $i$ indexing the $n$-set. I also have $n$ vectors of the appropriate ...
5
votes
2answers
147 views

Evaluate numerically an extremely small number

How to evaluate numerically $e^{-4 \cdotp 10^{35}}$ in the form $0,a_1a_2...\times 10^{-n}$ ...
3
votes
1answer
50 views

An issue regarding the use of CopyToClipboard with dynamic content

Please, consider the following code: ...
2
votes
1answer
46 views

Recognition Power Head for numeric value

We know: Map[Head, {a, a^2, a^3}] (* {Symbol, Power, Power} *) and Map[Head, {2, 2^2, 2^3}] all of them will be known as ...
1
vote
0answers
43 views

How can I use x->Root outputs from Solve? [duplicate]

Do not understand the meaning of the output given by Mathematica to this equation: ...
0
votes
0answers
41 views

EvaluationMonitor and variables with indices + subscripts

I have encountered the following problem while using EvaluationMonitor with NMinimize: variables that have both a subscript and an index, e.g. Subscript[x,y][1] do ...
0
votes
1answer
48 views

Manipulate curves [duplicate]

I want to draw curves with manipulation. When I use the following code, I receive nothing. ...
6
votes
0answers
46 views

How trap expression that doesn't evaluate?

If evaluating an expression produces an error, it's easy to trap that using Check or Throw......
1
vote
1answer
35 views

Access variable middle of the run [duplicate]

I execute a Table[] that need large time to be finished. If I abort it I loose what evaluated until now. Does it possible to stop running and save what evaluated ...
12
votes
1answer
888 views

Why is this 2D plot so slow?

I first do a 3D Plot of four surfaces (eigenvalues of a $4\times4$ matrix) over $kx,kz$ (setting $ky=0$ all along). And then I try to give a 2D plot along three connected particular lines in ...
0
votes
0answers
40 views

Substitute arguments before evaluating variables in Block [duplicate]

Suppose I have f = x^2; mod[x_] := Module[{}, f] Then mod[3] returns x^2. Is there any way to tell Mathematica to treat the "x" inside of f as the same "x" as ...
1
vote
0answers
68 views

Unexpected behavior of Set [closed]

Set doesn't work in some conditions. ...
11
votes
4answers
190 views

Evaluation of Alternatives

I recently stumbled upon a few examples that suggest patterns containing Alternatives do not evaluate for individual alternatives. For example: ...
1
vote
0answers
55 views

Solving a polynomial equation with an approximate constraint is slower than the symbolic solution

Why do these two operations have such different timing, when the only difference is specifying r as approximate $0.1$ vs arbitrary-precision $1/10$? Here are the ...
1
vote
1answer
84 views

How can I draw truth tables using Mathematica [duplicate]

For instance, the given expression p ⊕ (p v q) In the problem I'm trying to solve. There's a Mathematica answer to this: ...
0
votes
0answers
61 views

Approaching infinity [on hold]

I'm using Mathematica to visualize the autocorrelations of all kinds of wave-types. Obviously, my waves aren't infinite and don't have infinite periods though, so the autocorrelation I get is a ...
0
votes
0answers
39 views

Why doesn't Grid evaluate when I wrap all its arguments in Dynamic? [duplicate]

Here is a small program involving Dynamic: ...