Questions tagged [core-language]
Questions on the basic structure of the Mathematica language (Wolfram language) including atomic data types, syntax etc
567
questions
1
vote
2
answers
101
views
Change the output for `Times`function
When I have an input like:
1/2*k
The output is:
How to change the output of Timesfunction to see this result:
Another ...
- 1,223
1
vote
1
answer
87
views
Defining iterative algorithms [closed]
Assume the iterative algorithm of interest to be as follows:
...
- 145
4
votes
2
answers
143
views
Iconize behaves in a confusing manner
When I evaluate Iconize[Range[10], "range10"], it returns an icon labled "range10", which if evaluated returns ...
- 5,412
12
votes
2
answers
127
views
Bad Float Counts? (Length[xs] != Total@Counts[xs])
In Mma 11.3, tallying floats with Counts seems to fail. (Tally works fine, and rounding fixes the problem.) Is this behavior ...
- 13.1k
1
vote
1
answer
45
views
using strings from a header row as "pointers"
Suppose I have a list like:
data={{"product","amount","price"},{"A",1,100},{"A",3,100},{"B",5,200}}
I could use a Map to calculate over each row the "amount" * "...
- 3,740
0
votes
0
answers
67
views
Implementing a function that exhibits linearity
I am trying to define a function $\mathbb{E}_t$ such that $\mathbb{E}_{t}[f[x_{s}]] = f[x_{s}]$ if s<=t, and $\mathbb{E}_{t}[f[x_{s}]] = \mathbb{E}_{t}[f[x_{s}]]$ if s>t. $\mathbb{E}_{t}$ is ...
0
votes
0
answers
95
views
Is there a direct way of adding two random step size lists
As shown in the figure, I have three lists a,b and c. I want to see whether a + b +C0= c(here C0 is a constant).
Since list a and b have varing step size (...
- 91
6
votes
2
answers
265
views
Flat attribute : example I don't understand
I am just beginning to learn about attributes of function in mathematica.
I saw the example "Flat". But there is something I don't get :
...
- 2,085
3
votes
1
answer
156
views
Inspecting Mathematica object
I'm using ProofObject for my question, but it applies to other objects too.
FindEquationalProof returns ...
- 291
1
vote
0
answers
85
views
Is there packages can help read, analyze or understand MMA codes? [closed]
Sometimes, I think that it's difficult to learn high level codes, or even when looking back on some long lines of codes I myself had written, espectially when lots of pure-functions was used, so I'm ...
- 2,399
5
votes
3
answers
542
views
How to put the variable in a certain order after using "Solve[]"
I have this code:
...
6
votes
1
answer
67
views
unexpected result from augmented assignment to association
Is the last of these results expected? If so, how?
...
- 13.1k
1
vote
0
answers
113
views
raise error on type mismatch
Is there a best practice for raising an error on a type mismatch? For compiled functions I'm guessing the answer is the use of GeneralUtilities`WithMessageHandler. ...
- 13.1k
3
votes
1
answer
125
views
Module - Symbols out of scope of lexical scoping
The Problem
Consider the following code (1):
In[1]:= x = 2;
Module[{x, y},
y[x_] = x;
y[1]
]
Out[2]= 2
I expected the answer ...
- 1,115
8
votes
2
answers
479
views
Can we make a faster Boole implementation?
I just learned about Mr. Wizard's very efficient code here.
...
- 6,924
1
vote
3
answers
458
views
Unable to implement bisection method using recursion [duplicate]
I have tried to implement a bisection method for finding roots using SetAttributes[BisectionItt, HoldAll] and then ...
- 111
0
votes
0
answers
70
views
How can I better formulate a conditional statement?
To solve optimization problems I have seen this:
Is there a more elegant way to do this with alternative conditional expressions? Is there something equivelant to ...
4
votes
1
answer
65
views
Is it possible to write an expression A such that Evaluate[Evaluate[A]] is different from Evaluate[A]?
Mathematica is cool for all sorts of "magic tricks", but I'm trying to get an idea on how the core term-rewriting system works. Is it possible to make a term such that the output of its evaluation can ...
- 862
17
votes
1
answer
459
views
Distinguishing Wolfram Language and Mathematica, the software
Which features are part of Mathematica, the software, and which features are Wolfram Language?
I would say there has to be a line discriminating the two somewhere. One could say that Mathematica, in ...
- 4,846
14
votes
3
answers
246
views
What is the difference between Set and SetDelayed when evaluating the RHS leaves it unchanged?
I thought there was no difference between f[a_] = 2 + a; and f[a_] := 2 + a; because the resulting ...
- 1,116
3
votes
1
answer
250
views
Why did Set work instead of SetDelayed?
I started with the following expression
a[t_] := -Pi Sin(Pi/2*t)
where initial velocity is 2 Pi and initial distance is 1.
...
- 77
4
votes
1
answer
74
views
How can I evaluate only the (bound) variables in an expression?
Given an arbitrary expression, how can I have Mathematica only evaluate the (bound) symbols, i.e. replace them by their respective values, but not do any further simplification/evaluation of the ...
- 371
0
votes
1
answer
48
views
FunctionExpand vs FullSimplify
The documentation (v.11.3) says: "FunctionExpand is automatically called by FullSimplify."
Why then does ...
- 13.1k
1
vote
1
answer
56
views
undesirable/buggy change in behavior of Limit in Mma 11.2?
The behavior of Limit changed in Mma 11.2, and I think it is in some ways undesirable or possibly buggy. Consider
...
- 13.1k
1
vote
1
answer
83
views
What resources can I use to become familiar with high level syntax?
I was reading a question about dropping higher order terms and realized that I have a serous gap in knowledge when it comes to the finer points of mathematica computational programming. Are there any ...
- 95
1
vote
0
answers
61
views
What use is empty binding list in `Block[{},...]`? [duplicate]
Spelunking the Export function, I stumbled upon the following definition:
...
- 784
12
votes
1
answer
215
views
stable sort for association?
Should I be able to use the "list of functions" approach to getting a stable sort of an association? In 11.1 I see,
...
- 13.1k
7
votes
1
answer
145
views
advantages of ApplySides?
Version 11.3 introduces ApplySides for situations where I usually use Map. What is an example where ...
- 13.1k
3
votes
0
answers
385
views
How to achieve with Mathematica the effect a closure has in other languages?
Motivation
I want to write an auxiliary function (brief auxf) for testing the output of another function that evaluates its body repeatedly using ...
- 4,115
6
votes
1
answer
143
views
Is (x|y|...)∈set the same as x∈set&&y∈set&&...?
I've sometimes seen that this operator is used to specify that each of given variables is in some set, e.g. Reals. Like ...
- 7,082
13
votes
2
answers
176
views
Can a Symbol have more than one OwnValue?
The DownValues, UpValues, and OwnValues functions are all plural. In general, a Symbol may ...
- 1,299
4
votes
1
answer
123
views
SetDelayed not working as expected
According to the manual, "A variable defined with SetDelayed is evaluated every time it is used". The code below suggests otherwise.
...
- 6,408
13
votes
1
answer
554
views
Check if symbol is in core language
How can I check if a symbol is pre-defined by Mathematica, in a way that's backwards compatible with old versions?
i.e. I would like some CoreLanguageQ[x_Symbol] ...
- 1,278
1
vote
1
answer
186
views
Convenient value assignments in OOP
It is possible to implement OOP in Mathematica using something like
obj=c[<|a->1,b->2|>]
and it's convenient to extract value from the object by ...
- 9,373
0
votes
0
answers
35
views
How can I extract the numerical value from the result of FindRoot [duplicate]
I've to use previous values of FindRoot to implement my program (recursively), but the type of the output from FindRoot is not a number. How can I extract the ...
- 121
4
votes
3
answers
189
views
Keep only rules that replace integers with other integers
Let's say I have a list of replacement rules:
List1 = {2 -> 3, b -> 5.5, 6.57 -> 2, 3 -> 4.5, 1 -> -1, 0.03 -> 0.5, 9 -> a}
The desired ...
- 43
0
votes
2
answers
78
views
Numerical integration with a fixed sampling size, skipping points [closed]
I have a large number of data points to integrate over numerically. I would like to sample only some of the points and use a rather large step size just to reduce computation time.
Say the data ...
- 289
0
votes
2
answers
207
views
NIntegrating in $n$ dimensions?
I need to make a function that takes a function $f$ and a natural number $n$ and returns the integration from -inf to inf in all the $n$ dimensions of $f(x_1,\cdots,x_n)$. With Integrate I would do ...
- 299
1
vote
1
answer
88
views
any possible meaning to a "terminal" slash (/)? [closed]
I've been directed to the web page
http://functions.wolfram.com/07.31.16.0001.01
The first statement in the formula is
...
- 2,315
-4
votes
1
answer
156
views
how can i convert my matlab conde into mathematica or atleast convert the bisection program? [duplicate]
(Convert matlab code into mathematica code)
(I'm fairly new to mathematica)
(bisect function matlab code:)
...
- 1
0
votes
1
answer
88
views
SplitBy and mod 2 [closed]
I wish to group semiprimes into groups with same parity. Mathematica does this well with
SplitBy[ Select[ Range@ 100, PrimeOmega@# == 2 &], Mod[#, 2] &]
...
18
votes
2
answers
1k
views
Why it seems that there is no counterpart function as to multiplication, to `Total` as to addition?
Times and Plus have the same grammar, and so do Product and ...
- 9,503
0
votes
1
answer
108
views
Why 1 is not recognized as real? [closed]
I'm not understanding smth simple. Why is 1 not recognized as a real number in the second line?
- 683
3
votes
2
answers
657
views
Writing a bisection root finder
I'm trying to make a simple function that will calculate roots of equations by using bisection method. My code isn't working right. Can anyone take a look and help me?
Here is the code:
...
- 101
10
votes
1
answer
454
views
What does the ToList function do, and where did it go?
I am trying to revive some code from 2015 (version 10?) which uses the function ToList. I can not find it defined in any notebook on my system (in fact, it only ...
- 3,386
-2
votes
3
answers
270
views
11
votes
2
answers
1k
views
Can't understand one paragraph in Power Programming with Mathematica
In the chapter 7 of the Power Programming with Mathematica, there is a paragraph discussing the behavior of Set- functions: (page 205. (pdf version p. 224))
...
- 1,181
1
vote
0
answers
39
views
Is Construct introduced to replace Function application? Should it be treated as such an alternative?
I noticed that v.11.3 got released the other day; it was exciting so I went through the Summary of New Features in 11.3 to catch a glimpse of what's new and see if there is something I should keep in ...
- 4,115
0
votes
1
answer
881
views
Why is Null printing?
I am making a function that will evaluate several other functions, using the same inputs, in my program and give me the results. I am using Print to do this (see ...
- 123
2
votes
1
answer
186
views
Can the pattern "_." be used in head?
The standard usage of the pattern _. seems usually used in the parameter, for example, f_[a_,n_.]. I wonder if such pattern can ...
- 1,181