Questions on the manipulation of List objects in Mathematica, and the functions used for these manipulations.

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28 views

Problem with slot in If statement [duplicate]

I am struggling with slots, In this case I have a function int which gives either true or false. When it gives true, I want ...
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0answers
52 views

Generating the set of all three-dimensional binary arrays distinct under rotation and reflection?

How can I automatically generate all possible three-dimensional binary arrays of size $(x_1 \times x_2 \times x_3$) where each array is distinct from all others with respect to rotation and reflection ...
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0answers
32 views

Check if a (possibly nested) list is real [duplicate]

I have a very large matrix of numbers. I want to check if all its entries are real. At the moment I am using realQ = And @@ Thread[Flatten[Im @ #] == 0] & Is ...
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0answers
32 views

Updating List with Do works but not with ParallelDo [duplicate]

I am trying to find 5 minimas for some function. I can obtain the results if I implement a simple Do function. I tried to speed it up by using ParallelDo and then my code returns spurious results. ...
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81 views
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44 views

Arithmetic operations on columns [duplicate]

I have imported a file, data.txt, then plotted columns 2 and 3 as function of column 1 using the commands below. ...
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0answers
24 views

Create a (maybe nested) list of nminimize solutions in a loop [duplicate]

I'm a total newbie in mathematica, so need some help. I understand that my question is about basics, but i couldn't find the answer in docs, google and here. Here is what i'm trying to do. ...
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1answer
201 views

Remove list elements that contain NaN Symbol [duplicate]

I have a long list of lists ...similar to g = {{1,2,3},{4,2,7}, .....{1.2,9}}. Occasionally, g contains elements like ...
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0answers
16 views

logarithmic distribution of a range in fixed number of elements [duplicate]

I want to distribute a range between 4 to 93 in 50 numbers which are logarithmically distributed. How I can do this in mathematica?
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56 views

analysing data with MLF using (Oracle) Database connection

I'm testing the MLF package in Mathematica for datamining purpose. I start the databaseconnectivity with the following code: ...
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0answers
25 views

Threading a single abscissa through a list of ordinates [duplicate]

Suppose that I have the following list, called list. list contains elements X, ...
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0answers
87 views

Select {x,y} pairs from a list where x conforms to a rule [duplicate]

I'm working on some pet project and I have a very large list of {x,y} pairs. I want to make a new list containing all {x,y} pairs where x is, let's say, even (I actually need something more ...
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0answers
43 views

Store results of inequality [duplicate]

I eveluated some values using Reduce commend and I store them in a Table ...
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0answers
63 views

How to delete duplicated sublist [duplicate]

I have a list like this: ...
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0answers
43 views

is there a way to speed up rule replace? [duplicate]

I am currently doing calculation with 7 parameters, each parameter set corresponding to a value. And I store the data in the format as a list of rule, like following ...
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0answers
27 views

Eliminate some value from a matrix [duplicate]

I have a function that return a table consisting of a 2D points. These points are either {x,y} or {0,0} ...
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1answer
38 views

Pruning coordinates in subarrays of a list conditional on them having non-real components

If I have a list of 2D coordinates placed in subarrays of a data structure like the following: ...
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0answers
42 views

How to manipulate lists to get only part of the value [duplicate]

This is really a question about manipulating the output of Maximize. I have a function of 2 variables, defined thus: ...
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0answers
35 views

How do I plot cities on a Map? [duplicate]

Right now, I have the 20 cities with the most population in the world, given by the lines of code ...
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0answers
24 views
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1answer
144 views

Do loop - variable does not change [duplicate]

I got the follwing code which should add a '1' 100 times to an empty list. plotVals = {} Do[Append[plotVals, 1], {l, 1, Nmax}]; The output is again an empty ...
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0answers
11 views

Part::partd error on one of two similar lists [duplicate]

I have run into a problem that I can't explain. Here is the code: ...
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2answers
108 views

how to export nested list

I have a ListPlot where I extract my data again using pts1 = Cases[(*I put my list plot here*), , x_Point :> First@x, Infinity]; which gives me the data as ...
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1answer
95 views

Problem with List Dimension Outer Map [duplicate]

I am currently handling a big list which has the following dimension: {6, 3, 4, 2, 2, 1, 8} where the last number 8 represent a ...
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0answers
58 views

Partitioning a list by specifying the lengths of the sublists [duplicate]

Suppose that I have an ordinary, one-dimensional, fully flattened List of expressions. Here is an example, a List called list: ...
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0answers
63 views

Defining functions in a loop [duplicate]

I have a symbolic solution to a linear system with respect to some variables a[i,j] which depend on a parameter t. sol=Solve[...,Table[a[i,j],{i,0,n},{j,0,n}]] I ...
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0answers
45 views

List elements and iterator name collision [duplicate]

Let there be two lists, exp = {{i, i}, {j, j}}; exp2 = {{r, r}, {o, o}}; and there are two Table commands to access them. Then, ...
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0answers
70 views

Importing specific columns of a .txt file [duplicate]

I have text delimited file, with data in four columns. How to use ReadList to extract only the first and the fourth column.
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0answers
107 views

How can I revise my program to avoid “No more memory available”? [duplicate]

I have a program for calculating a type of list. ...
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0answers
39 views

Generating partitions of a set with a specified size of the parts [duplicate]

I tried the following (inspired by the answer here) myList = {a, b, c}; Needs["Combinatorica`"]; SetPartitions[myList] and I got this answer, ...
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0answers
116 views

How can I solve this system of functional equations?

I would like to use Mathematica to find maps a, b, c, d, e, f such that ...
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0answers
97 views

How to combine file data chronologically via reading numbers in a filename and put it in one list?

Say I have a bunch of files with nearly same filename, eg. data_timestep1, data_timestep2, ... The data itself in one file is ({x1, y1, z1, absolute field value 1}, {x2, y2, z2, absolute field value ...
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0answers
29 views

Error in extracting a column [duplicate]

I imported excel data to Mathematica using this command. kuruzD = Import[ "C:\\Users\\TMH\\Documents\\Problem Set 4\\kuruzData.xlsx"][[1]] //TableForm I want to ...
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0answers
48 views

DeleteCases and Inequalities [duplicate]

I would like to remove cases from a list according to an inequality rule - e.g. remove all values less than x. I can do the following but this seems very clumsy: ...
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0answers
38 views

Correspondence between eigenvectors and eigenvalues [duplicate]

Let us say I have a matrix h (2x2). Now, I want to get the eigenvectors and eigenvalues of my matrix h: ...
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0answers
60 views

get while loop output into a list [duplicate]

I would like to get the output from this while loop and use it as a list so I can count the frequency of the various tuples.. ...
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0answers
48 views

How to ContourPlot a Table? [duplicate]

Possible Duplicate: Why is ContourPlot not displaying this curve? Why do I have to put Evaluate[] here I'm trying to plot certain contours of a function $f:\mathbb R^2\to\mathbb R$. What I ...
-1
votes
3answers
359 views

Combining lists

How can I combine list1={{x1,y1},{x2,y2},{x3,y3}} and list2={{x4,y4},{x5,y5}} to ...
-1
votes
2answers
86 views

Manipulate store values

Is there a way to store the numerical values from a manipulate function in the form of a table? For example, if the function is f[x_] := x^2 - 2x Can one store ...
-1
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2answers
218 views

How can I extract when a select condition is met in a do loop the value of the iterator?

I use the following code to find out the number of consecutive prime numbers using a formula $n^2+n+i$ found out by Euler (starting from n=0): ...
-1
votes
2answers
457 views

Convenient methods to sum select rows (or cols) of a matrix? [duplicate]

What are some convenient methods to sum selected rows or columns in a matrix? This question Summing along rows or columns of a matrix only addresses how to sun entire rows or columns ie, by level. ...
-1
votes
1answer
372 views

variable sized lists and using lists as variables

I am trying to scan a parameter space of varying numbers of parameters subject to some constraints (I am interested in any number of constraints just out of curiosity, but in reality no more than 2 ...
-1
votes
2answers
110 views

Plotting solutions of differential equations with different parameters

I want to plot x[t], when i manipulate w from 0.1 to 1.5. Here is what I've attempted, which does not work as expected. ...
-1
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2answers
101 views

Extracting only complete records from two data sets and combining them

I have two data sets: ...
-1
votes
1answer
99 views

How to separate a vector into two vectors, one having the first half of my original vector and the other having the second half

I have a set of n vectors with an even length. Let us make an easy example with 3 vectors of length=4: ...
-1
votes
1answer
100 views

Plotting the results of a system of equations

I believe this is a question of more list manipulation than plotting, but I hope you could help me. I solve numerically a system of equations of 3 variables, take only real solutions where one of the ...
-1
votes
1answer
128 views

Efficient Table Generation & NDSolve Error

I'm currently working on solving an SEIR model with data from the CDC. I've created a function to calculate the Square difference for the model and want to create a table of values for the 4 variable ...
-2
votes
4answers
165 views

Compare elements in a list

Assume that there are three different points in x-y coordinate like: p1={4, -1}; p2={5, -2}; p3={1, 5}; In order to compare these points to each other in a ...
-2
votes
1answer
79 views

Using Product for different variables

when using product in mathematica the initial and maximum value of the product will be the variable itself that will be maupulated. what I need is to make these initial and maximum of the product as ...
-2
votes
1answer
266 views

Non-regular grid data

I have issue with non-regulary spaced data. I have set of 3 numbers {x, y, z} in my list. ...