Linked Questions

5
votes
5answers
204 views

On reimplementing the Select function [duplicate]

I am working through the course Programming Paradigms via Mathematica. One of the exercises asks that you construct a function that mimics Select,even with three ...
6
votes
2answers
186 views

Modifying parameters: Set::setps in the part assignment is not a symbol [duplicate]

Ok, this will probably be a silly question, but I can't get my head around it. I'm making a simple module that, given a list and two integers, will swap the position of the elements in the ...
1
vote
2answers
471 views

How to define a function based on the output of DSolve? [duplicate]

I would like to define a function based on the output of the following DSolve call: ...
2
votes
2answers
226 views

Find minimum value of function which calls NDsolve [duplicate]

I have defined a function which takes a coefficient for a differential equation as an argument, solves the differential equation with NDSolve, and returns the value of the solution at time t=10. I can ...
4
votes
1answer
181 views

Check if an inequality holds among the solutions returned by Solve [duplicate]

Let's say I solve a system: Solve[{a == 3* c, b == 2 *a}, {a, b}] and then want to see if the values found for a and ...
0
votes
1answer
363 views

Fitting a Function With a Numerical Integral [duplicate]

I am having trouble using FindFit with the following function. ...
0
votes
2answers
228 views

Replace doesn't replace the denominator [duplicate]

I have the following expression in Mathematica -((E^(2 - 2 Sqrt[(x[1] - x[2])^2]) (x[1] - x[2]))/Sqrt[(x[1] - x[2])^2]) I want to replace anything of the ...
0
votes
1answer
154 views

Change input variable in a function [duplicate]

I'd like to write a function, that would take a matrix as an input parameter and would change it by multiplying one of its rows by a factor. I try to do it in the following way: ...
0
votes
1answer
92 views
1
vote
2answers
71 views

How to define a variable updating function? [duplicate]

I tried to program a Sudoku solver when I suddenly ran into this problem: I need a function which effectivley does this: ...
0
votes
1answer
265 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 ...
0
votes
2answers
91 views

How to contourplot a function defined via findroot? [duplicate]

when I use contourplot, the system will simplify the expression first with its parameters holded. However some expressions can not be simplified first without inputting parameters, for example, ...
1
vote
1answer
125 views

What is wrong with setting one list to another within function? [duplicate]

I have built a function which carries out a set of operations given two parameters. The function looks as follows: ...
2
votes
2answers
86 views

Adding a tree to a list of trees within a loop [duplicate]

I'm trying to write a function which for a list of trees checks if a given tree is isomorphic with any of the listed, and if not - adds it to the list. I tried to use both ...
0
votes
0answers
142 views

The /. syntax in numerical methods [duplicate]

I have an analytical approximation method for solving an ODE and want to compare this to an NDSolve solution, but the syntax is confusing me. To get the solution from NDSolve, I define the ODE as eqn ...

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