Questions tagged [syntax]
Questions on the correct (or improved) formulation of Mathematica code to achieve particular results. Use this tag (not "symbol") for questions about all those odd @@ /@ # & and _ characters, which are keyboard shortcuts for the Wolfram Language named functions Apply, Map, Slot, Function, and Blank.
1,014
questions
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16
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Question about rule syntax/format for CellularAutomaton function
I am trying to understand how to use CellularAutomaton function. For example, I am interested in the Game life and I found a working example here. However I cannot understand or find a detailed ...
4
votes
2
answers
132
views
How to speed up the following algorithm?
I have some random combinations of numbers pairs (where numbers range from 1 to some ntest) ...
6
votes
2
answers
148
views
Is there a system option to make Mathematica generate syntax error when reading code from file which has red syntax warning in frontend?
I type some equations from text books into database, which later read from Mathematica to solve.
Since I do this manually, sometimes I make mistakes where I type ...
0
votes
1
answer
74
views
How to select non-repeating pair of numbers?
Consider the following combinations of integers comb, where the integers range from 1 to n ...
0
votes
0
answers
26
views
Enforcing multiple domains in Reduce function [closed]
I would like to have two different restriction for the domains of my variables.
In particular, in the following code, I'd like to have q to be a natural positive number. Is there a way to do that?
<...
4
votes
2
answers
205
views
Trying to Solve system of equations gives empty result
First-time user of Mathematica. I have three equations, and I'm trying to solve for one of the variables.
I'm hoping this is just a syntax problem.
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0
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0
answers
41
views
Invalid variables error in SolveValues when using an array of variables
I was attempting to run some code similar to the simple example below.
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1
vote
1
answer
104
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Fastest splitter?
Consider some dataset
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2
votes
2
answers
95
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Analog of monitor which does not lead to freezes of the interface
I have some heavy computation wrapped by Monitor and ProgressIndicator. It is the template:
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3
votes
2
answers
130
views
Different behavior of Clear in different versions of Mathematica
Consider the following code:
list1 = {1, 2, 3};
m = 17;
{list1, m} // Clear
In Mathematica 13.2, this syntax with Clear works ...
1
vote
1
answer
62
views
Problem with RegionNearest?
Consider the following region:
...
0
votes
0
answers
65
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Any way to eliminate evaluating cells except for "Abort evaluation"?
I have a notebook with many cells, one of which contains an evaluation of some condition. If it is False, I want to have an automatized way of the "Abort ...
3
votes
0
answers
72
views
Keeping track of braces and brackets { } [ ]
It doesn't take much to end up with lots of braces, i.e, { or }, and brackets, i.e., [ or ], in even a single line of MM code, and it's very easy to lose track of how many there are and where they ...
7
votes
1
answer
371
views
What is the diffrence between these three commands?
Consider
F=1/((x-a)(x-b)) ;
G= 1/((x-α)*(x-β));
H=1/((x-r[1])(x-r[2])) ;
Using Apart[], the partial fraction decomposition ...
2
votes
0
answers
75
views
Optimizing prallel computing for nested integration
I need an advice for optimization of computing with ParallelMap, as well as general hints to speed up computing discussed below. I have several questions about this ...
0
votes
1
answer
154
views
Partial differential equation with conditions
I am trying to solve this PDE with Mathematica, and I have checked the syntax a lot, but still don't get a solution
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1
vote
1
answer
66
views
Syntax::sntxf when using ItoProcess
The following code gives an error message Syntax::sntxf. What is wrong with my code, and how can I fix it?
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3
votes
1
answer
88
views
Multiple dropdown dialogs in the same window?
Consider a few dropdown dialogs:
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3
votes
0
answers
66
views
Making speed of MemberQ comparable with explicit If?
Consider the following two lists:
listtest = {11, 13, 22, 221, 1, 3} // Sort // N;
pdglisttest = RandomInteger[{-222, 222}, 10^6] // N;
For the given element of <...
5
votes
3
answers
414
views
How to find the nearest element that is bigger than x?
Consider some list
list=RandomReal[{0,1},10^6];
I would like to find the closest element to some value of x that is larger than it, and also extract its position. ...
3
votes
4
answers
214
views
Destructuring the left-hand-side of `Optional[s:v]`
It is useful to be able to provide default values in pattern-matching, for example, if an element has a key but no corresponding ...
0
votes
2
answers
98
views
How to build the following region?
Consider a 3D figure defined by the dependence $\Delta x(z),\Delta y(z)$. One example is a pyramidal frustum, for which $\Delta x, \Delta y$ are linear functions of $z$, and $z$ lies inside the ...
2
votes
1
answer
53
views
ReplaceAll that works inside Rational?
I'm trying to replace all instances of a 31632259 in a formula with x, but there's something special about how Mathematica ...
3
votes
0
answers
220
views
How to solve the following integrodifferential equation by generic approach?
Consider the following equation:
$$
\frac{\partial f}{\partial t} - p H(t)\frac{\partial f}{\partial p} = \mathcal{I}[p,t], \tag 1
$$
Here, f = f[p,t], with p being ...
2
votes
2
answers
111
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How to "complete" the table by making all of its rows to have the same number of elements?
Consider the following table:
...
0
votes
1
answer
58
views
Syntax error trying to rewrite expression using rules
I want to use Mathematica to calculate derivatives of some long, complicated expressions. I have an integral with integrand $I_*$ which is a functional that depends on $h(x,t)$ and $\phi(x,t)$. The ...
0
votes
1
answer
73
views
How to re-organize the table in the following way?
Consider the following table:
tab=RandomReal[{0,1},{5,10}]
How is it possible to convert it into the form of a 2-column table ...
0
votes
2
answers
106
views
How to combine the tables in the following way?
Consider two tables
tab1 = RandomReal[{0, 1}, {5, 4}]
tab2 = RandomReal[{0, 1}, {10, 4}]
How to quickly make a table where the ith row of ...
2
votes
1
answer
105
views
How to code retarded time in Lienard-Wiechert potential equations?
I have been making strides on my project with the help of others here but have run into another snag: I am having difficulty in expressing the Lienard-Wiechert potentials with retarded time. For ...
2
votes
4
answers
133
views
How to transform the data in the following way?
Consider the following data:
...
1
vote
0
answers
80
views
How to emulate the curves and color of the video? [closed]
I found this animation on the internet, it is part of a joke, but I was intrigued by how the video can be emulated with the colors and the curve proposed in the video.The video talks about neural ...
4
votes
4
answers
158
views
How to check if at least one ordering of the given row matches one of the rows of a table?
Consider some list of elements
...
2
votes
4
answers
216
views
How to check if the given row matches one of the rows of a table?
Consider some table
tabb = RandomInteger[{0, 4}, {5, 4}]
and a row
row = RandomInteger[{0, 4}, 4]
How to check if ...
8
votes
2
answers
368
views
Reverse the rotation of an animated gif and create a mirror image of it
I need Mathematica code to reverse the rotation direction and viewpoint of an animated GIF named "wheel." The current rotation is counterclockwise, and I need it to rotate clockwise while ...
0
votes
2
answers
113
views
How to automatically convert sub- super-indices to strings?
Consider the following expression:
expr = "\!\(\*SubscriptBox[\(m\), \(t\)]\)"
I would like to convert it to the ordinary string e.g. ...
0
votes
2
answers
91
views
Clip, Select, FirstPosition not working for extracting values from an association based on a range from another list
I have this dataset of associations:
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4
votes
6
answers
276
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How to leave only specific columns?
Consider the following table:
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0
votes
0
answers
27
views
Problem with repeated cells evaluation using tags
Consider the following code:
...
1
vote
0
answers
28
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Generator of limits of successions according to type of indeterminacy. Correct syntax
I am trying to make a limit generator with 3 columns, number of the exercise, the second column is the limit (perfectly written with n-->00), and the third column is the result of the limit.
I have ...
0
votes
0
answers
41
views
How do we create a function for the recurrence relation in terms of a dependent variable?
Suppose
S = {{-1.5, 1}, {0, 1}, {1.5, 1}, {1.5, 0.1}, {0, -0.1}, {-1.5, 0}, {1, -1.4}, {-1, -1.5}}
How do we define the recurrence relation as a function of the ...
0
votes
0
answers
51
views
Way to download all attachments from yahoo.com
For a long time now I want to download the attachments from my yahoo.con mail, only the files, no text, but in batches, so MMA gets into my mail and downloads every attached file it finds in a folder.
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2
votes
1
answer
108
views
Why axes arrows are not present? [closed]
Consider some test data
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3
votes
5
answers
474
views
How to find the most repeating row?
Consider the following table:
tab={{1,0,0,1},{1,0,0,1},{0,1,0,1},{1,0,0,1},{0,0,0,1},{1,0,0,0},{0,1,0,1}}
Could you please tell me whether there is a command which ...
0
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0
answers
78
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How to compile a code with a table having varying number of columns?
Consider the following table:
...
1
vote
2
answers
98
views
How to extract the following data from the file?
Consider the following file. It has the form
...
0
votes
1
answer
46
views
How to define the following rule for all objects in a compact way?
Consider the following symbolic definitions:
...
4
votes
1
answer
127
views
Put text in Graphics3D syntax?
Some friends from the forum helped me to make this MMA script, I have tried to modify it to put text similar to the image, perhaps with a more beautiful letter, but I can't think of how, I have seen ...
1
vote
2
answers
128
views
How to define the following "derivative"?
Consider the following test expression:
...
3
votes
2
answers
119
views
How to make two sub-sets each with two distinct elements having a list with 4 elements?
Consider the following list:
list = {{meson1, p1}, {meson2, p2}, {meson3, p3}, {meson4, p4}}
I would like to organize it into two sub-sets, each with two elements, ...
2
votes
3
answers
145
views
How to extract specific terms from the polynomial?
Consider the following polynomial:
...