Questions tagged [procedural-programming]
Questions about Mathematica's procedural programming paradigm.
313
questions
2
votes
1
answer
78
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
243
views
0
votes
0
answers
50
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
76
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
45
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
4
votes
1
answer
91
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 ...
- 595
2
votes
2
answers
372
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 ...
- 123
1
vote
1
answer
43
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):
...
- 1,723
2
votes
1
answer
45
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
170
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 ...
- 4,343
1
vote
1
answer
116
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
53
views
2
votes
2
answers
183
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 ...
- 285
1
vote
3
answers
104
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
1
vote
0
answers
64
views
How can I make ParallelDo faster than Do?
I am trying to optimize my code as much as possible. So first I used a compile and now I am trying to parallelize the code in order to make it faster because in the end I will need to make a loop that ...
- 21
0
votes
1
answer
119
views
How to use for loop in Mathematica?
in most of my job I have to repeat something for different part of data, for example making plot, usually the only thing need to change is index. Below is the example of the code which I have to ...
- 383
0
votes
0
answers
38
views
Concatenate string with the value of each element of a vector/list
I have a vector/list t = {4, 5, 6}. I want to output each element (its value) of t in a string of characters. For example, the ...
- 443
1
vote
1
answer
49
views
Why each iteration takes longer than previous one when using VariationalD in this loop?
I have a function $f$, and I would like to modify it iteratively to approach another one called $a$ (not because I think this is the best way to do anything, but for experimentation). For this, I use <...
- 137
2
votes
2
answers
79
views
Could anyone please help with defining a vector function of tons of variables?
Could anyone please help with effectively defining a vector-valued function of tons of variables so that
...
- 21
10
votes
2
answers
470
views
What is the most efficient way to define a Loop until function?
Mathematica has the While function which is very convenient when we need to process some code until the attainment of a certain state (identified with a condition). ...
- 1,087
0
votes
1
answer
101
views
An example code for doing a loop [closed]
I would like a code that works for doing loops as in the toy example below. This would help me to understand how to work with loops in more general contexts as I am still a beginner in Mathematica. ...
- 207
0
votes
1
answer
70
views
Parallelization in While[] loop when testing if a condition is met
Well, I am trying to run the following code:
...
- 1,723
3
votes
3
answers
136
views
Do loop so that I do not get double terms?
I have a Do loop where I generate quantum state equations <111||111>,<111||112>...<232||232>. This is 144 equations in total but I want both bra and kets to be seen as the same so ...
- 33
0
votes
0
answers
80
views
The use of `NestList `
After read Michael answer, code use NestList to compute and feed in numerical integration. I want to learn this idea into my code.
In the ...
- 445
1
vote
0
answers
50
views
Loops Not Working- Kernel Crashes and Values Incorrectly Updated
I haven't used Mathematica in a while so any help is very greatly appreciated.
I am trying to run a program with nested for loops that runs two function evaluations in the inner most part of the loops....
- 179
2
votes
2
answers
94
views
How to realize NDSolve by NSolve with the implicit constraint equations?
Daniel post the amazing code to realize numerical integrators, I think it is useful to the kind of one-step explicit equation like x[k+1]-x[k]== constant_number. In ...
- 445
0
votes
1
answer
48
views
How to compose an algorithm to create new array (based on array data), if I need a reference to an array being created, no for loop, in mathematica?
I have an array with either 1 or 0. From this, I am trying to create a new array with intervals.
I have some base interval, one step, we can say 1 second here. If there is 0, I skip, if there is 1 I ...
- 3
0
votes
0
answers
54
views
How to use Mathematica to return value from for-loop [duplicate]
I tried to use Mathematica to implement random generator. The pseudo code I use is as following:
...
- 47
0
votes
1
answer
64
views
Evaluation self notebook with loop
I have a large notebook with multiple sections. I would like to run the entire notebook with one variable change kquads.
At the end of the notebook, I added one loop
...
- 141
1
vote
0
answers
63
views
"With" use in a (implicit) nested loop
Symbolic code:
Do[g[longcat[i,k],longcat[i,k]],{i,1,f[k]},{k,1,m}]
Longcat is loooong and occurs several times in my expression g...
- 887
4
votes
1
answer
105
views
Binary permutation list code in Mathematica
Given some natural number $N$, I am interested in the set of all binary permutations of length $N$ (with the intention of storing in lists depending on how many $1$'s appear in each permutation). My ...
- 271
0
votes
0
answers
56
views
matrix problem: evaluation of column values which depend on a variable
I do not use Mathematica for a long time and I have a question about a matrix problem.
I add here the code:
...
- 1
0
votes
1
answer
73
views
How to clear all things inside a loop?
It happens to me a lot when I write a loop, I have to Clear all functions, variables, definitions and etc to be sure my calculations is done correctly. namely as a ...
- 1,047
2
votes
0
answers
102
views
Building a Matrix as a piecewise-function of the indices without for loops [closed]
I'm very new to Mathematica and this site. I've read that building matrices with For loops is slow, and I have experienced this myself on the current project. I'm trying to wrap my head around ...
- 21
2
votes
2
answers
103
views
How to implement If criteria for the NestList-Function
I have a function which bisects a list in two parts recursively. Unfortunately I have to select a number of iterations for the NesList-function which is just an ...
- 53
0
votes
3
answers
402
views
Python recursive bisection algorithm to Mathematica
I've been sitting on this problem for a while and i am kind of stuck. I am pretty new to Mathematica and have been trying to implement a recusive Algorithm, which splits/bisects a list of items in ...
- 53
2
votes
1
answer
177
views
Cannot assign variable value inside Do Loop
This is more of a conceptual problem.
Suppose I have three lists.
x1 = {1, 2, 9, 10};
x2 = {5, 6, 7};
x3 = {9, 10, 13};
Now, I wish to keep only the first two ...
- 1,050
1
vote
1
answer
44
views
Increment FindMinimum range
I have a function SQ[b,zQ,zh] where I want to find at which zQ it is a minimum. The parameters are ...
- 339
0
votes
0
answers
55
views
view linebreak symbol
As you see in the above example, In[294] and In[295] looks just the same, but the outputs are different.
The fact is that there is no linebreak symbol in In[294], but there is one linebreak symbol in ...
- 2,825
2
votes
2
answers
272
views
0
votes
1
answer
30
views
How to create ParallelDo loop with n dimensions of evaluation?
For example if I have n=2 i get
ParallelDo[something, {v[1], c[1]}, {v[2], c[2]}]
and if I have n=3 I get
...
0
votes
0
answers
53
views
Check an input matrix M contains any nonzero diagonal matrix element or not
Is there a way to easily check an input matrix M contains any nonzero diagonal matrix element or not?
For example,
if the M contains any nonzero diagonal matrix element, Output: True.
if the M ...
- 101
-1
votes
1
answer
79
views
Costly function inside nested Modules [closed]
The function initDataTable simply reset all data to Black first, then set the bottom right quarter to ...
- 149
2
votes
2
answers
69
views
How can I store vectors in a matrix
I am triying to generate realizations of a Gaussian random process using the KL expansion. For that, I need to multiply an eigenvector for an eigenvalue and a random variable.
I have tried
...
- 115
2
votes
1
answer
137
views
Repeating and Sequencing Procedures with two Do-loops
I have a Do loop where I'm looking for the value of certain parameters that respect the conditions inside an If, and with those values, a run another Do to make another calculation of an expression ...
1
vote
1
answer
49
views
How to get a loop for a differential equation system?
I would like to know how can I obtained a loop of this system
...
0
votes
0
answers
58
views
Replacing the print display in a for loop
I am running a For loop as follows:
table = {};
For[n = 0, n < 10, n++, {table = Append[table, n], Print[table]}]
I was wondering if there was a convenient way ...
- 755
2
votes
1
answer
64
views
-3
votes
2
answers
103
views
How to change a Do loop to a For loop? [closed]
I'm a rookie in the loops. I would like to use a For loop to get a solution like using a Do loop.
...
- 53
1
vote
1
answer
80
views
How to change a Do loop to a while loop?
I'm a rookie in the loops. I would like to use a While loop to get a solution like using a Do loop.
...
- 53