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

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3
votes
1answer
52 views

SelectionEvaluate executes out of turn

I'm seeing some unexpected (to me) behavior from SelectionEvaluate. I've got a notebook with two sections. In section 2, I've got code that clears the notebook's ...
3
votes
1answer
83 views

Why doesn't my expression evaluate at the subkernel?

Consider this code: ...
3
votes
1answer
90 views

Defining a function that prints both the name and value of a variable defined locally within the calling function

To save time when debugging with Print statements, I'd like to define a function -- call it PrintVal -- that prints both the name and value of a variable defined locally within the calling function. ...
3
votes
1answer
114 views

Strange integration

Bug introduced in 9.0 or earlier and fixed in 10.1 Note: Beginning with V10.1, this integral returns unevaluated but without error messages. I tried to evaluate this line ...
3
votes
1answer
75 views

Print prints into the Messages notebook rather than into the evaluation notebook

Some time ago I noticed that the results of the evaluating the function Print[something] does not emerge in a new cell created in the notebook where the operation ...
3
votes
1answer
64 views

Apply a function to the current selection in place

Say a have the function foo: foo[x_] := x + 2 Like the Evalution ...
3
votes
1answer
129 views

How to calculate the residue of $1/f(z)$ at a numerical approximation to a root of $f(z)$?

The input Residue[1/DirichletL[19,10,s],{s,s0}] gives 0 even when s0 is a root. For ...
3
votes
2answers
172 views

Evaluate in Plot leads to function error

Please help - I'm really struggling to understand why this evaluates with errors. ...
3
votes
1answer
494 views

Use output of NDSolve as an integration limit of NIntegrate

I've been working on a ODE, for a function y[t], that, due to it's complexity, has to be solved numerically. I then need to use the results of NDSolve, which I ...
3
votes
1answer
307 views

FunctionInterpolation Errors / Question re Evaluation Order and Options

I have using Mathematica functions that takes a Cartesian coordinate relative to the Earth (xyz) and converts it to a latitude, longitude, and altitude (lla). And here it is: ...
3
votes
4answers
88 views

Working with ScheduledTasks inside DynamicModules

I have a question - is it possible to run ScheduleTask[] inside DynamicModule[]? What I have tried so far: ...
3
votes
1answer
303 views

Expanding huge expressions that simplify and factor

The following is for Mathematica 8.0.4 running on Windows 7 laptop (6GB memory). I have eight expressions that are unexpanded multivariate polynomials in 6 variables. They are huge expressions, so ...
3
votes
1answer
70 views

A problem about sorting final result

Three days ago, I asked a question about B-Spline Basis fuction here @Michael E2 given a solution to make the order of interval looks normal The easiest way would be to sort it afterwards: ...
3
votes
1answer
418 views

kernel Local crashes during the course of a For loop

I want to find the minimum of the function r[x,p] subject to the constraint w[x,p,t]==0 (t ...
3
votes
1answer
980 views

Why does Mathematica evaluate Sin[2.0] but not Sin[2]?

I can't understand why is it that In[88]:= Sin[2] Out[88]= Sin[2] while In[89]:= Sin[2.0] Out[89]= 0.909297 I even tried ...
3
votes
2answers
154 views

Keep data in memory inside a notebook without having to evaluate it again [duplicate]

I have a notebook that calculates some data in a relatively large time so I want to keep these data saved inside the notebook without recalculate them every time I open the notebook. I know I can ...
3
votes
1answer
385 views

is there a method to send different cell evaluation to different core

I am running Mathematica on a computer with mulicpu and every cpu has multicore. I am wondering if there exist a method to send different cell evaluation to different core? So if I already have a ...
3
votes
1answer
103 views

Some _atomic elements' TreeForm looks confusing with Level in appearance

In[1]:= Level[1/2,{-1}] Out[1]= {1/2} TreeForm[1/2] ...
3
votes
2answers
60 views

Simplify with assumption of unknown function [duplicate]

I have an unknown multivariate function entry[x,y,z], which is positive. Then how to get FALSE and entry[1,2,3] in the following evaluations? ...
3
votes
2answers
74 views

Mathematica automaticly evaluates some cells

Is there a command or a trick to tell Mathematica to not automaticly evaluate some cells? I use the NMinimize function to calculates some coordinates and then use ...
3
votes
1answer
653 views

Order of operations, precedence in Mathematica [duplicate]

I get confused in the order of operations in Mathematica. For example, f /@ 10^{1, 2, 3} {10, 100, 1000} In my head, that ...
3
votes
0answers
80 views
3
votes
0answers
51 views

Is there an analogue of Evaluated->False (in FindRoot) for FindMinimum?

I guess functions like FindRoot, FindMinimum, etc puts the estimation number into the expression, and then do other ...
3
votes
0answers
54 views

Why does FreeQ seem not to work with complex numbers?

I guess I do not understand how Mathematica evaluates this simple expression inside FreeQ ...
3
votes
0answers
86 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. ...
3
votes
0answers
168 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 ...
3
votes
0answers
812 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-> ...
3
votes
0answers
109 views

Assign variables from list inside With or Module

I have found that it is possible to assign variables from lists, as follows. r = {1, 2, 3}; {a, b, c} = r; b 2 However, ...
3
votes
0answers
70 views

Non-preemptive evaluation of a dynamic function? [duplicate]

I want to monitor a long calculation that is triggered by the release of a Slider. While one can indicate running calculations when the main evaluation loop is ...
3
votes
0answers
497 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: ...
2
votes
2answers
335 views

Get the approximate analytical solution to an algebra equation

Is there a way to get the analytical form to the root of this equation: 2 A e (-ArcTanh[smax/s0] + ArcTanh[(smax Cos[w ζ])/s0]) == F0 ...
2
votes
2answers
146 views

How to make Mathematica returns the exact expression I typed

I'm using Mathematica to compare some constants. Before playing around with those constants, I would like to check that I didn't make any mistake in typing them. So my question is the following: "What ...
2
votes
3answers
100 views

Evaluation inside a Manipulate

Let's assume I have a symbolic expression, and inside a Manipulate I define the actual values: ...
2
votes
2answers
148 views

Time delayed evaluation of a function

I'd like to write a function that delays the evaluation of a function (say) $5$ seconds after I hit Shift+Return. Is this possible?
2
votes
1answer
241 views

Nested Derivative

These two expressions are mathematically the same, but when substituting with the same rule, yield different results. What is happening? ...
2
votes
3answers
549 views

Select sublists with second element nearest to zero

I've got some big lists from which i need some data (one of the big lists). To be specific, I need to divide this biglists in sublists of the same length (10000), and form a new list with the mean of ...
2
votes
3answers
5k views

Step-by-step definite integration

I am interested in obtaining the intermediate steps for rather straightforward symbolic definite integrations (e.g., from an elementary calculus text). As an example, for $\int_0^1 x\,dx$ I'd like ...
2
votes
3answers
159 views

Dynamic plot with Evaluate on expression

I'm trying to make a make a plot of a table of expressions, which should be pre-evaluated (since they are infinite series with analytic sums). I'm able to make the plot normally with ...
2
votes
2answers
64 views

Get the unevaluated expression from a numbered cell

If a cell exists as below: In[1] := (xyPoints = {{1,2},{2,5},{3,10}}; ListLinePlot[xyPoints]) Is it possible to get at the expression rather than the plot shown ...
2
votes
2answers
82 views

PasteButton: Pasting expression name without quotation marks?

I am struggling to find a way to use PasteButton to paste the name of an expression (in particular a list) without showing the contents of the expression or without ...
2
votes
1answer
88 views

Block assignments not quite sequential?

With scalars, Block acts like Scheme's let*, that is, the assignments (appear to) happen sequentially: ...
2
votes
1answer
72 views

Show [In] and [Out] tags after quitting Mathematica

I cannot find a way to show [in] and [out] tags when evaluating cells after I close the application. Is there a way to keep these shown? I disabled the kernel in global options but cannot transfer ...
2
votes
2answers
64 views

function definition with a given list of parameters: how to use Evaluate[] properly?

given a list of variables variables = {a, b, c}; I want to automatically define a function f[{a_,b_,c_},x_] := g[a,b,c,x] ...
2
votes
2answers
124 views

Handling a sequence of unevaluated arguments

I have the following piece of code: ...
2
votes
1answer
246 views

Is there a way to simplify a symbolic expression at assignment, once-for-all?

I have a series of symbolic function calls that could be greatly simplified using some assumptions. I think I would like for these assumptions to be used in the definition of the function so that they ...
2
votes
2answers
122 views

Merging two held expressions into a held compound expression

Consider e1 = Hold[a = x + x; b = y + y + y]; e2 = Hold[c = a + a + b + b + b; c^2]; How can I obtain the following? ...
2
votes
1answer
122 views

Strange results of definitions using OwnValues

I am asking this question simultatenously with this one, which is strongly related. I was trying to see if I could create the behaviour as in that question without using ...
2
votes
2answers
311 views

While loop doing cell evaluation not completing

I am trying to get a loop structure using While to repeatedly evaluate another cell referred to in its body (using a cell tag). ...
2
votes
2answers
327 views

Evaluating Polynomials at Grid Points

I am continuing my quest on B-splines. The code below builds a 5x5 matrix out of B-splines, using the BSplineBasis[] routine. I now want to evaluate the polynomials that are stored in each matrix ...