Questions tagged [procedural-programming]
Questions about Mathematica's procedural programming paradigm.
346
questions
2
votes
6
answers
439
views
All solutions that satisfy $ x_{1}^{5}+x_{2}^{5}+x_{3}^{5}+x_{4}^{5}-x_{5}^{5}=0 $
I want to find a combination that satisfies all the solutions of the following formula.
$$
x_{1}^{5}+x_{2}^{5}+x_{3}^{5}+x_{4}^{5}-x_{5}^{5}=0
$$
$x_{1}$, $x_{2}$, $x_{3}$, $x_{4}$, and $x_{5}$ are ...
- 525
0
votes
1
answer
107
views
Performance improvements using Table and Compile
I'm converting a code from MatLab to Mathematica. It takes MatLab less than a second to compute it while its more than ten minutes in Mathematica. I was hoping to improve the performance.
Here's a ...
- 376
1
vote
0
answers
39
views
Parallelization with procedural functions, e.g. `AddTo`, `PreIncrement`, and so on
I have a problem that procedural functions don't work with parallelization, e.g. AddTo and PreIncrement. At first, I thought it ...
- 876
0
votes
1
answer
47
views
How make a function NestUntilList that accepts multiple arguments?
Recently the looping construct Until was added to Mathematica in 13.1, based on the ResourceFunction Until created by Jon Mcloone.
I want to make a generalization named NestUntilList.
NestUntilList is ...
- 1,653
0
votes
0
answers
28
views
Stack Solve solutions in a loop [duplicate]
I want to solve the following equation in a loop:
...
- 51
0
votes
2
answers
119
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Real-time function graph display
I would like to see how the graph of the function en[B, i, j, k, p] changes depending on i, j...
- 1,731
0
votes
0
answers
69
views
Do loop Implementation
I want to generalise the following algorithm to a loop overall possible subsets of the original set.
the algorithm has the following form:
ver={X41,X42,X43,X44}
and
...
- 21
2
votes
1
answer
61
views
4
votes
3
answers
402
views
A loop in which three indices are changed
How could this piece of code be written in the Table, or as simply as possible?
...
- 1,731
0
votes
1
answer
91
views
0
votes
1
answer
89
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Can I use Table or something else instead of While in this case?
I have a very long code that take an extremely large amount of time. I have been using the While loop, but with each iteration, it gets slower and slower, so I know there has to be a better way of ...
- 175
0
votes
0
answers
50
views
Solving a set of an arbitrary number of coupled differential equations
I have to solve a system of b coupled ordinary differential equations of the following type:
...
- 1
4
votes
2
answers
117
views
How to discard the repeating elements of a list [closed]
Lets say there is a random list of expressions :
a={Sin[x], Sin[3 x], Sin[4 x], Sin[x], Sin[4 x], Sin[x], Sin [5 x], Sin[3 x], Sin[5 x]}
Plot[{a}, {x, 0, 2 Pi}]
...
- 811
2
votes
2
answers
128
views
The way of converting a string to a variable in a loop?
I have 60 txt files which I want to import them into Mathematica using a Do loop. Each file contains some numbers (more precisely, a list of numbers). I want to put ...
- 1,248
1
vote
1
answer
64
views
Jacobian General::ivar issue
I have a differential equation labelled by eq0 and I want to use finite-difference method to solve it. First, I have to set up the system of equations ...
- 551
1
vote
1
answer
108
views
My ParallelDo does not work
I have to do a lot of calculations that take lot of time, and using a Do loop is simply too long. It is the first time I am using ...
- 33
2
votes
0
answers
112
views
The fastest and most scalable way to write a nested loop
The problem is to find the weights {w1,w2,w3,w4} that satisfy the condition. Which is the fastest and most scalable way (e.g. for 10000 weights) to write this ...
- 35
1
vote
2
answers
124
views
Trying to apply numerical method with Do
I am trying the following scheme to learn to implement an iteration using Do loop. I tried to implement the same method using for loop but with same errors. I, therefore, turned to the Do loop to ...
- 19
0
votes
1
answer
51
views
Sorting a list by increasing order algorythm [closed]
Im new to loops on mathematica,was wondering how could I create a function to loop through a list which finds the index of the smallest value of that list, makes a sublist from index 1 to that ...
- 93
3
votes
2
answers
84
views
How to NIntegrate multiple ranges of data at the same time with an output that can be plotted?
I am trying to use the NIntegrate function to find the difference in the area beneath two 2 dimensional splines (how much area of the river bed was lost or gained from one year to the next) but, I ...
2
votes
2
answers
460
views
How can I make 10 variables from a for loop?
I used a for loop to make 4 variables:
For[i = 0, i < 4, i++,bi=0]
But when I write b0 or ...
- 359
-1
votes
1
answer
74
views
0
votes
1
answer
89
views
Length of a For loop [closed]
How to find the length of a For loop?
Here is a simple example:
For[i = 0, i < 4, i++, Print[i]]
0
1
2
3
How to find that there are in total 4 outputs using ...
- 319
5
votes
2
answers
278
views
Perform same operation along dimension of an array
If I want to add the $2\times 2$ matrix b along the first dimension of a that has $n\times 2\times 2$ dimensions I can do this ...
- 654
0
votes
0
answers
44
views
How to "freeze" a parallel program
I wrote a program, parallelized it (using ParallelDo[], SetSharedVariable[] etc.), and enjoyed the wonderful speedup. ...
- 123
2
votes
0
answers
47
views
How to make my own external language cell evaluator
We can type > and select python to insert python external language cell into notebook.
Then we can write python code inside it and evaluate it by pressing ...
- 7,094
4
votes
1
answer
171
views
Why won't my random walk work in a Mathematica Do loop? [closed]
This produces a nice random walk plot:
...
- 599
3
votes
1
answer
42
views
Keep Reap / Sow results after breaking out of a loop [closed]
I am doing a long calculation where I create a list using Reap and Sow. However, sometimes this calculation gets too wild and I ...
- 51
0
votes
0
answers
119
views
How to Loop initial conditions to solve a coupled differential equation using nested for?
I need to solve the following pair of coupled differential equations and find the plots for the ground state radial wave function, the potential and the energy eigenvalue for the ground state.
$$V''(r)...
2
votes
1
answer
133
views
How to create a loop in Mathematica?
Yup, im a newbie, you guessed it. But I have been having fun solving Project Euler problems with Mathematica. I am on problem #8:
The four adjacent digits in the 1000-digit number that have the ...
- 53
3
votes
3
answers
166
views
Quit the loop if encounter error message
First define length-component error (personal term) :
This is an error when we want to get n-th component of a list if n is bigger then the length of the list. For example, ...
- 4,037
2
votes
2
answers
215
views
While loop not working problem [closed]
I am new to Mathematica ,and I am trying to implement this while loop which adds all odd Fibonacci numbers less than or equal to 2 million but it keeps outputting 0 for sum.
Any solutions for that?
...
- 31
2
votes
1
answer
285
views
Why is this Do-Loop taking so much time?
I have this simple Do Loop that, for some reason, takes a really long time for $h<\frac{1}{15}$. Why is this so? Is there a more efficient way in programming such a recursion?
...
- 307
2
votes
1
answer
162
views
How to use same cell for printing in a loop?
I want to manually tag images.
For example, we prepare a list of images like
imgList = Table[Rasterize[i, ImageSize -> 50], {i, {a, b, c}}]
it gives
Now I made ...
- 16.9k
6
votes
1
answer
916
views
Save loop output in a data file
I started working on Mathematica today. I'm trying to save the result of a loop in a file as a column, very simple to do, but hard for someone who doesn't know Mathematica syntax. Here is my code:
<...
- 63
2
votes
1
answer
187
views
Loop over multiple variables with readable code
I've seen similar posts to this, but not with as many variables. I need to loop over 8 variables, with only two values each(1 and 2), so I can loop over the 16 possible input and output states, and ...
2
votes
2
answers
275
views
0
votes
0
answers
56
views
Algorithm consisting of modules returning multiple errors
I'm trying to write a genetic algorithm that will take a list of lists of reals in interval [0,1], my "starting population", "score" them according to a fitness function, append ...
- 65
0
votes
0
answers
92
views
While loop to solve a diffusion problem
Crossposted at Wolfram Community: https://community.wolfram.com/groups/-/m/t/2506329
I am trying to use a While loop to solve for a diffusion problem using the power iteration method. The code is ...
- 1
3
votes
1
answer
105
views
Trying to add up values into a matrix
first post here.
I'm currently completely stuck and frustrated with mathematica. In retrospective, it might had been a mistake to use it for this, I'm actually considering to somehow export the ...
- 33
1
vote
1
answer
106
views
Monitoring Table or Do with Print
Imagine I want to track the progress of constructing a complex Table or Do object by temporarily printing the iteration number. ...
- 4,187
4
votes
1
answer
164
views
Efficient iteration of matrix multiplication into a table
Suppose I have a list of matrices $(A,B,C)$ and a vector $v$. I want to construct a table whose elements are sequential applications of these matrices to $v$, i.e., the first entry will be $Cv$, the ...
- 647
2
votes
2
answers
471
views
How to put a FOR loop in a WHILE loop
I have a strange matrix like this one in the picture
Now, my goal is to change all the 1s with random complex numbers of modulus 1, but if the element $a_{12}=z$, then $a_{21}= \bar{z}$, so the ...
- 135
3
votes
2
answers
105
views
Check certain expression using a while loop to run through all posibilities in a range
Well, I have written the following code (using the fast square root test found in this answer):
...
- 1,941
2
votes
1
answer
48
views
How to convert a While into a NestWhileList
How do you rewrite this While statement with NestWhileList? I know you can easily get this done with ...
- 93
2
votes
2
answers
189
views
Calculating successive derivatives of a monomial list using a Do loop
I've got the following monomial list:
monlist={c x^3, x^5, 4};
I need to compute the successive derivatives of that list of monomials such that when the derivative ...
- 11.4k
1
vote
1
answer
238
views
How to calculate Jensen-Shannon divergence?
How to write the function (or any other methods) to calculate Jensen-Shannon divergence (JSD) for two (p and q) discrete probability distributions? I need to calculate JSD for too many different (over ...
- 383
0
votes
1
answer
60
views
2
votes
2
answers
209
views
How to put Break command within a Do loop over 2 variables
Suppose I have the code
Do[If[f[i,j]==1,{output[i]=j,Break},Continue],{i,1,5},{j,1,1000}]
Where $f$ is just a function.
I want the code to find the first $j$ that ...
- 295
1
vote
3
answers
112
views
Optimizing operations between vectors
Basically I am generating a grid in space (so a vector where v[[1]]=position 1 in x) and a random number of particles in space (so a vector where p[[1]]= position of particle 1 on space).
Afterwards, ...
- 21