# Tagged Questions

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

169 views

### Select a certain row among the duplicates

I have the following problem: I have a (a lot)*3 table, meaning that I have 3 columns, say X, Y and Z, with real values. In this table some of the rows have the same (X,Y) values, but with different ...
97 views

### How to extract info from Association? [duplicate]

How can one extract a list of keys and a list of values from the association? e.g. as = <|a->1, b->2, c->3, d->4|> ...
76 views

### Joining sub-lists nested two levels deep in a list [closed]

I have an obviously easy task, but I can't do it, and I could not find a solution by searching the site. I have a list as follows: ...
78 views

### Incompatibility of Append and NumberForm? [closed]

Consider the code list = {.12, .23, .34}; Append[Round[list, .1], 10] Append[NumberForm[list, 1], 10] The use of Round returns the expected result ...
198 views

### Max function used with nested lists

I have a list as follows lis1={{{1,5,6},{4,7,8}},{{1,2,2},{5,6,7}}} and would like to calculate the max value of each nested list in order to get following ...
95 views

### Tracking solutions over a Brillouin zone

Thanks to @bbgodfrey I have a function that finds the two solutions to a set of equations bounded by a hexagonal region (corresponding to the Brillouin zone). It takes the angle ...
140 views

### Pairs of data to Classify[]

Suppose I had the following data a={1,2,3,4,5} How would I turn this into b={{1,2,3}->4,{2,3,4}->5} That is, ...
457 views

### Generate a list

Given the list o = {xmin, xmax, ymin, ymax}; how can I generate the following list? ...
454 views

### How can I use nonlinear model fit with multiple variables? [closed]

I have a data set with four entries. the first three entries correspond to variables in the fit x,y, & z. The fourth entry corresponds to the function value. I am trying to fit this data to a rate ...
182 views

### How to trim the zeros from the right of a list? [duplicate]

I need to remove the zeros from the right of an integer list up to the first non-zero element. Such as {0,1,0,0,2,0,0}->{0,1,0,0,2}. Padding zeros can be simply ...
150 views

### How to import data from a .mat or a .txt file and manipulate dimensions

I'm new to Mathematica (I know very, very little - so I apologize if anything I say is absolutely wrong) - but I'm trying to upload a file from matlab and arrange it in matrix form. I have a .mat file,...
45 views

### Truncating a List of Subsets of Ordered Pairs

I have a set of pairs: ...
164 views

### Manipulating List?

I have a huge list with 1000 elements. Manually entering and calculating SUM of probabilities it would take a few hours. Example: list = {1, 2, 3, 3, 4, 3} ...
72 views

### Matrix iteration failing after second step

I am calculating 11x6 matrix using different logics as in below code. Problem is in Do loop in below code where I have two different criteria to update matrix "fd". I am expecting logic in IF which ...
64 views

### Replace element of matrix based on rule which invloves other element of same matrix

I am trying to replace 1s row of matrix d iteratively from right by multiplying last element in 1st row with (1-int*dt) to generate 2nd last element. The replacement continues till I reach the 1st ...
123 views

### How can I reshape my solutions to make a 3D plot?

I need some help on the following. I need to run Solve for multiple values of a and b. To do so instead of using Do, I use ...
71 views

### Replace parts of nested lists

I have list of stock data as follows: lis1= {{{1992/10/12, 126.946, AEX}, {1992/10/13, 127.85, AEX}}, {{1992/10/12, 88.487, AFLI},{1992/10/13, 91.825, AFLI}}} ...
238 views

### List and patterns

Given some tuple $\{N,M,L\}$ such that $N\geq M\geq L\geq 0$ and $N>0$, how can I generate all tuples $\{n,m,l\}$ such that $n\geq m\geq l\geq 0$ and such that ...
51 views

### Gather elements in sublist by first element for the purpose of summing [duplicate]

I have data which looks like this: ...
236 views

### 2D Interpolation of data file

I hae a datafile with 5 columns of the structure: x_i f(x_i,y_1) f(x_i,y_2) f(x_i,y_3) f(x_i,y_3) f(x_i,y_4) with i = 1 to about 100. Thus there are about ...