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

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131 views

Built-in symbols which are more close to the root/core of Wolfram Language

Seeing the vast scope of science covered by the Wolfram Language (WL) and the large amount of built-in symbols (functions), I am curious to know which built-in symbols are more close to the root of ...
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117 views

Are there any videos that show how different Mathematica expressions are evaluated?

Are there any videos that show how different Mathematica expressions are represented internally as object graphs and demonstrate how they are transformed during an evaluation? I am asking because I ...
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102 views

Why the flat f[x] is treated as ghostHead_[f[x]]?

While reading this answer I feel confused. If we do not care any specific detail of the original question, then ybeltukov's answer essentially makes use of the following fact ...
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133 views

Can I define an axiomatic (Boolean algebra) system and prove theorems using Mathematica?

The general question is Can I define an axiomatic system and prove theorems using Mathematica? The more concrete one is about Boolean algebra. I consider this axiomatic Boolean algebra system ...
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62 views

Regarding Evaluated True

Done a bit of reading: Normal[Series[ ]] does not give a normal expression Regarding the Evaluated->True, consider: ...
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39 views

Use EvaluationCompletionAction to notify me only after long evaluation

Is it possible to use the option EvaluationCompletionAction to notify me (e.g. with a Beep[]) when an evaluation that took ...
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189 views

DynamicModule, SaveDefinitions and global functions

Unfortunately, I had not checked stackoverflow, because there, the exact same behavior was already reported. Please see the Q&A "SaveDefinitions considered dangerous". Up-front, I'm on Ubuntu ...
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77 views

Problem with inequality using refine

I am using inequalities to follow some line of reasoning in Mathematica and I came across a problem I can not explain to myself. Does from a>=0 and b>=0 not follow a+b >= 0? How does Mathematica ...
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106 views

Dynamic and Refresh

If I am not mislead by my memory, in Mathematica 6 a function Refresh was introduced, having the options UpdateInterval and ...
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74 views

Functional-Style Fixed-Length Queue Object?

Following up on question Side-effecting an array in an association? and @Mr.Wizard's answer in there, I'm modernizing and tweaking Daniel Lichtblau's efficient queues and ran into a little roadblock. ...
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154 views

Memory problem in Mathematica 10

I'm having a problem with memory. I'm doing nonliner fits of several data lists to a system of differential equations. When I evaluate the "Do" cycle the memory grows with the iteration step up to my ...
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416 views

A is fast, B is fast, but together they're Mathematica-crashing slow?

I'm trying to do something with finding solutions to a quantum mechanics problem with n wells. If there are 40 wells, I need to find the solution to an equation in the form: ...
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44 views

What is the difference between GenerateDocument and TemplateApply[NotebookTemplate[

Abstract GenerateDocument[ _NotebookObject ] seems to do the same what TemplateApply[ NotebookTemplate @ _NotebookObject ] ...
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132 views

Mathematica shift-enter problem

Would really appreciate if someone can help with this problem: When I first open a Mathematica note book, say you do 1+2 and press shift-enter. As expected, I get "3" as the output. Now suppose you ...
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64 views

$Epilog does not work when exit

The following code does work: $Epilog := Print@1; Quit[]; But if I close the document and exit WM or click QuitKernel, it does not work. Why?
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73 views

Assign a value to a variable without using Set or SetDelayed?

I supose probably yes, but at the end I assume that internally mathematica has to use Set or SetDelayed. Am I right? Background: I am developing a super simple phraser that takes a code description ...
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78 views

Assign variables from list inside With or Module

I have found that it is possible to assign variables from lists, as follows. In[1]:= r = {1, 2, 3}; In[2]:= {a, b, c} = r; In[3]:= b Out[3]= 2 However, if I try ...
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287 views

Lazy evaluation/loading of parts of an expression

Is it possible to have an expression x such that its elements are only evaluated when they are individually accessed, for example when evaluating statements like ...
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113 views

Strange double evaluation using MorphologicalGraph

(MMA 9.0.0 on Mac OS/X 10.8) Please consider the following snippet (this is as SMALL as I could make it -- my attempts at making a smaller repro-case eliminated the effect that I am investigating) ...
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37 views

Unexpected order of evaluation in ForAll

I noticed that ForAll behaves rather unexpectedly when its first argument is a symbol which has been Set in an outer scope. For ...
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75 views

How can I use L.Shifrin s code formatter package better

in the document of HoldAllComplete, it says: Evaluate cannot be used to override HoldAllComplete.. for example, when I'm ...
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83 views

Smart pointer for Mathematica?

Would the implementation of the smart pointer idea be possible in Mathematica ? Let's say I have an object "o" of the form Class[object] where object is an Association, and Class has the HoldFirst ...
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106 views

How to make a graph of this function?

I need to plot the following function: ...
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42 views

Question on Function in Replacement Operation

I am trying to create a replacement function which, depending on the input, gives an additional minus. In my example I have an undefined function a with two ...
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80 views

Summing the probability distribution to 1 to convince myself

I have worked out a probability distribution and want to check its sum which is necessarily 1. First we write $$ r \triangleq \frac{(2 \lambda + \mu)^2}{2(\mu + \lambda)^2}, \quad s \triangleq ...
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53 views

Is it possible to pipe the output of EvaluationMonitor to Excel?

I have an EvaluationMonitor setup to capture the points processed by NIntegrate. This is a case where the same function, integrated over the same region in cartesian coordinates yields a dramatically ...
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78 views

How to implement nested With as a single construct using functional programming (Fold)?

It is possible to define my own With construct where each local constant can depend on the previous defined local constants? I wish to replace something like this ...
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102 views

Expression for evaluating multiple functions?

I am constructing 3D data points for a plot and corresponding to specific conditions "manually". I define the values of five parameters [these I always have to define myself]. From those, I evaluate ...
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334 views

Is there a way to stop evaluation immediately?

Sometimes I'll have a loop that I accidentally made too big. I'll evaluate, and MM will try to run through the entire loop. The program itself doesn't actually seem frozen... I can go to Evaluation-> ...
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25 views

What makes items with head `Function` different?

I apologize beforehand for the muddleheadedness of this question. It reflects the fact that I'm trying to interpret outward "behaviors" of Mathematica expressions without having any understanding of ...
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23 views

Timing of an Evaluation is not correctly displayed

From: http://reference.wolfram.com/language/howto/DisplayTheTimingOfAnEvaluationInANotebookWindow.html I ran a process that took about two minutes to finish. But the time recorded is only 0.18 ...
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27 views

Alter evaluation order when applying scalar multiplication to function

Consider the following program: g = 2f; g[x] (* (2f)[x] *) Is there any way I can change the above expression to have it return ...
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73 views

How can I solve this expression?

I'm trying to solve this expression for A, but I'm not sure how. ...
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62 views

Calculating the rank of an abstract matrix

I'm trying to compute the rank of a 4x4 matrix with 4 parameters and 2 variables. I tried to calculate its rank under some assumptions on those conditions and I kept getting rank 4. So I did an ...
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0answers
70 views

How to prevent long evaluation and infinite loops

I'm new to this, so sometimes I accidentally ask Mathematica to do calculations with numbers so big that it can't handle it and it immediately freezes my laptop to the point where there's nothing I ...
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0answers
57 views

Creating a lazy evaluator of the lambda calculus

I have a sub project in my research to write a lazy evaluator of the lambda calculus. How should I approach this problem? I already have a implementation of the lambda calculus in another language. ...
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102 views

How to speed up my code with constructing matrices

I have run this program for a long time to get the result for n = 2048(about 5hours) and no more result till now (can't run with n = 4096). I would know how to make it more efficient. Any help or ...
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74 views

Trying to Simplify an Expression

I'm trying to simplify an expression: ...
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47 views

Order of evaluation when using Solve and Minimize

I have to solve numerically an integral, that ends up being more or less as follows: Solve[f[x]==a*Sum[Sin[x-i]*(f[i]-f[i-1]),{i,1,x}],f[x]] (not actual ...
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27 views

Expanding Function Based on Congruence Classes

I'm trying to get Mathematica to expand $\quad \quad \beta_n=\sum_{r=0}^{n}\frac{\alpha_r}{(q^4;q^4)_{n-r}(q^4;q^4)_{n+r}},$ where $\alpha_r$ is an integer valued sequence that is given by ...
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96 views

Mathematica not evaluating q derivative of Jacobi theta function

Jacobi theta functions, $\theta_a(u,q)$ for $a=1,2,3,4$ are defined in the unit disk $|q|<1$. For some reason that I would like to understand, Mathematica does not evaluate numerically the $q$ ...
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55 views
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135 views

Mathematica not responding

I am working in the field of applied physics. Some body suggested me to use Mathematica for plotting graphs and programming. After going through some tutorials, I have written the following code but ...
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48 views

System of Nonlinear equations with Gamma and Incomplete Gamma function

The next two nonlinear equations are cumulative ratios of a production system. The mathematical model includes two essential parameters (n, tau) that can be obtained by solving this system. I'm ...
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67 views

kernel stops evaluation, clears variables

I am using the new Mathematica 10 student edition. As I am evaluating a table of integrals and calling NIntegrate repeatedly, the evaluation stops without error and the kernel clears all variables. ...
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48 views

Evaluation inside Compile

here's a simple question: I have a function: ...
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64 views

CreateDocument using a specific Evaluator (Kernel)

I was trying to build a button to create a new document that contained a dynamicaly changing table. In the parent notebook i am using another kernel - not the usual "Local". The problem is that in the ...
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195 views

Select and plot real positive solutions for a sixth order parametric equation

I need your help in order to solve the following problem: I have a sixth order equation: $ax^6+bx^5+cx^4+dx^3+ex^2+fx+g=0$ and I solved it using Solve[] command, ...
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144 views

Integrating and plotting pde system solution

I have a trouble with plotting a pde system solution. I'm solving a PDE system in 2-dimensional space and then I want to integrate the solution along one dimension and build a log plot along the ...