For questions about defining recursive functions, recursive algorithms and solving recursive equations.

learn more… | top users | synonyms

1
vote
1answer
32 views

RecurrenceTable [on hold]

I got an error saying ...
0
votes
2answers
55 views

Help Solving A Recusive System: “$RecursionLimit::reclim: Recursion depth of 256 exceeded.”

Was wondering if anyone had any tricks/ideas on solving this system of recursive equations I have. Essentially my goal is to have J2 equal to zero, but to understand how tweaking several parameters ...
-2
votes
1answer
64 views

Recursion depth of 1024 exceeded [on hold]

I'm not sure why this code is giving the error :( f[0] = 0; f[n_] := f[n] = DigitCount[n, 10, 1] + f[n - 1]; f[1016]
0
votes
1answer
30 views

Function to Represent Recursive Integral

I'd like to represent the following recursive integral equation to evaluate/graph (for $n\leq3$): $K_{i,n}\left(x\right)=\intop_{x}^{\infty}K_{i,n-1}\left(y\right)dy$ where ...
0
votes
2answers
45 views

Solving linear recursions without constant depth in mathematica

Mathematica does not like this recurrence relation. I do not understand why? ...
0
votes
1answer
76 views

How to improve this function that selects parameters from arbitrary distribution using Recursion?

Below, I have defined a function using Which to select model parameters based upon various conditions. My questions are: Is there any danger in writing this function using Recursion? Is there a more ...
1
vote
2answers
54 views

Solving Recurrence equation for n

I have a recurrence equation $t_n$ which is defined as $$ t_n=2.5t_{n-1}-1.5t_{n-4},\qquad \text{for }n\geq5 $$ Where $$ \begin{align} t_1&=5\\ t_2&=10.5\\ t_3&=26.25\\ t_4&=62.625 ...
0
votes
1answer
65 views

Problem with recursion depth

I want to solve a problem where I need to compute the Euler-Lagrange equation. However I receive a recursion problem, and I don't understand why. ...
0
votes
1answer
48 views

Solving recursion equation with two parameters

I am trying to solve the following recursion equation, a(l,m)=l*a(l,m-1)+a(l-1,m) with initial condition; a(l,m)==0 if l=0 , a(l,m)==1 if m=1 I am trying to solve it ...
0
votes
1answer
57 views

Recursive definition of nested sums

I have a set of functions which take lists as arguments. They recursively nest sums, and I have defined them as follows ...
1
vote
1answer
70 views

How to rewrite and possibly speed up a recursive sum?

I have the following for-loop calculating a multiple nested sum ...
4
votes
1answer
96 views

Display level of recursion of a recursive function during execution

Given a recursive function, is there some simple way to display or store the value of recursion or "how many levels deep" the function is at a given time? For instance, if we wrote the recursive ...
1
vote
1answer
54 views

Implementation of a recursive function [duplicate]

I have been trying to implement a recursive function, but still struggle. Here's what I have written: ...
0
votes
0answers
73 views

Simple recursive function?

I'm new in Mathematica and need some help. I'm trying to make a recursive function but I'm not sure how to iterate through more than one item. To be more clear, take this pseudo code for example: ...
1
vote
0answers
52 views

Problem with converting recursive code to iterative

I am trying to convert a snippet that uses recursion into one that uses iteration for drawing an L-tree, but my code produces duplicate points. How do I avoid generating them? Recursive version: ...
1
vote
1answer
134 views

how to make a recursive function to analyse this file

I am stuck at this problem beginning We assume we have keyword k, and the structure in the file: file.txt ...
1
vote
1answer
84 views

Function to calculate finite difference

I wrote a function to calculate multivariate finite difference of different orders ...
0
votes
1answer
53 views

How to define y[n] = f1 y[n-1] + u[n]?

I need to define a recursion defined by the following equation $y(n) = f_1 y(n-1) + u(n)$ In which $f_1$ is a symbolic constant. I know the values of the sequence u and I know the initial value of ...
2
votes
2answers
129 views

Understanding `NestList` with multiple functions

General question For a function f[n, a], where a is a list and n is a whole number, what is ...
0
votes
1answer
88 views

Recursive functions taking list arguments

I wish to create a function that takes lists (e.g. {plus,plus,minus,0,minus,plus}) and uses the input list to calculate a corresponding value using a set of ...
0
votes
0answers
91 views

simulate a 32-bit signed integer overflow in a recurrence function

Considering the following recurring equation: which is this factorial function: I want to find the value of x where f(x) = 0. Actually, the solution is impossible with Mathematica, and it's ...
0
votes
0answers
41 views

Different kind of numeric erros when plotting recursive functions

I have been trying to plot some numeric solutions to a Hamiltonian system. Basically I have ...
1
vote
1answer
89 views

solve recursive factorial function [closed]

Is there a way to solve this recursive factorial function? a[n + 1] = (n+1)*a[n], a[10]=10 I am looking for the value of a[n] ...
3
votes
1answer
85 views

Mathematica taking too long to calculate recursive function

I have been trying to plot those specific recursively defined functions p1 and q1 in Mathematica: ...
5
votes
2answers
579 views

Variable that changes itself

I am trying to store a boolean value into a variable with the additional property that the value changes each time the variable is called. ...
0
votes
0answers
108 views

Nested Recursion Equation

I have been trying to solve a "nested recursion equation" using Mathematica. However, when I do something like this: ...
3
votes
3answers
186 views

Pare down list recursively

What is the best way to pare down a list whereby the $n$th number is removed from the list recursively? This ...
5
votes
0answers
116 views

Second order differential equation with boundary conditions solving repeatedly

I want to solve a second order differential equation in the interval[-1:1], which does not have a analytic solution, \begin{eqnarray} y''(x) &=& k \phi^2(x)y(x) \\ \phi(x) &=& ...
1
vote
1answer
150 views

Define a Recurrence Table involving other tables

I'm relatively new to using Mathematica. Previously I used Matlab, but lately I noticed that the numbers i got in both of them do not match (mostly it seems that Matlab lacks precision...). The ...
5
votes
2answers
202 views

Plotting two recursive functions

I'm trying to plot two recursive functions (p and θ) on a map. So far I have: ...
14
votes
6answers
579 views

How can I evaluate only a single step of a recursive function?

Let's say have a simple recursive function for the Fibonacci sequence f[0] := 1 f[1] := 1 f[n_] := f[n - 1] + f[n - 2] but I want to see how it will expand in a ...
0
votes
2answers
135 views

Square root estimation

I happened to read a something online about estimating a square root in a very simple way, known as Heron's method or the Babylonian method for square roots. The following (python?) code was included ...
1
vote
0answers
47 views

Central binomial coefficient [closed]

I am tasked with creating a recursive definition of the binomial coefficients that stores previously calculated values. this is what I have: ...
21
votes
3answers
1k views

Visualisation of a recursive function

Is there a way to nicely visualize recursive functions? (diagrams/plots) More specifically I'm looking for a way to make contrast (visually) between e.g. the cosine function which if continuously ...
8
votes
2answers
299 views

Recursive partitioning: Is there a better way to do this?

Consider the following function, which recursively splits a list into equal length sublists (the length of the list is assumed to be a power of the second argument): ...
10
votes
5answers
653 views

How to deal with recursion formula in Mathematica?

In engineering problems, I am always seeing many recursion formula. For instance, In the book "The NURBS book", I discovered many recursion formula Fibonacci ...
3
votes
2answers
214 views

A problem about recursion formula of deCasteljau algorithm

I use mathematica to realize the deCasteljaul algorithm $$\vec{P}_{k,i}(u_0)=(1-u_0)\vec{P}_{k-1,i}(u_0)+u_0\vec{P}_{k-1,i+1}(u_0)$$ The graphics that deCasteljaul algorithm generated as below: ...
3
votes
4answers
157 views

Plotting recursive from a for loop

our assignment is that we have make a plot for the possition of 1's From the recursive function if a[n-1] is even then ...
1
vote
1answer
102 views

How to find the closed formula for a recursion [closed]

From theory of recursive functions, an example for linear recursion is: $$ f_x = 0 \ \ \ x\leq 1$$ $$ f_2 = 1$$ $$ f_n = f_{n-1} + 8n - 18$$ If you want to find out a close formula for it, one way is ...
7
votes
2answers
188 views

Solving with DSolve recursively

I need to find $f(x,n)$ in the interval [0,1] defined by recursion, \begin{equation} \frac{d f(x,n+1)}{dx} = f(x,n) \end{equation} with boundary conditions $f(0,n+1) = 1$ and $f(x,0)=1+ x $ Using ...
1
vote
0answers
62 views

RSolve with simple initial condition

Suppose we have the following equation: $$ g_ma_m=r_ma_{m-1} $$ with initial condition $a_L=d$ and $L$ might be negative. The following command ...
4
votes
2answers
270 views

How to find a recurrence relation for a numerical sequence?

This question was inspired by Vladimir Reshetnikov's question (How to find a recurrence relation for a sequence?): Given a finite sequence of numbers, how can we find in MMA a recurrence relation ...
7
votes
1answer
122 views

How to find a recurrence relation for a sequence?

I have a sequence given by an explicit formula for n-th term: ...
2
votes
1answer
141 views

Implementing local variables of a recursive function with either Module or Block

First, some quick background: I have been eagerly learning Wolfram and Mathematica for two months now, and along the way have written about 250 pages of teaching material that has ballooned into a ...
7
votes
2answers
86 views

Recursive function with array of variables

I am trying to create a recursive function which works with an increasing array of variables. Since the formula is quite complex, i will try to simplify my example to the core of my problem. The ...
5
votes
1answer
188 views

How can I make a “self-referential” replacement operation self-contained?

Fairly often I find use for replacement rules that call themselves on the right-hand side of the rule, e.g.: ...
5
votes
1answer
70 views

Specifying Range of RSolve

When I input RSolve[{0 == q[n + 1]^2 + 3 q[n + 1] + 2 q[n + 1] q[n] - 6 q[n] + q[n]^2, q[0] == 1}, q[n], n] I get two complicated-looking complex solutions: ...
4
votes
2answers
179 views

Integrating a periodic function

I have a periodic function ff: ff := Function[x, Piecewise[{{ff[x - 1], x >= 1}, {2 x, 0 <= x < 1}, {ff[x + 1], x < 0}}]] Plotting it works fine: ...
0
votes
0answers
37 views

Scoping in recursive function leading to unexpected results

I'm trying to implement Ramer-Douglas-Peucker line simplification in Mathematica, and I'm running into an issue with recursion. My implementation of the algorithm is below: ...
1
vote
1answer
177 views

Programming a recursive FFT with Mathematica

I'm trying to program a FFT using a recursive function in Mathematica, though my program is not getting me anywhere at the moment. Could you say what's wrong with it and what I can do to make it work? ...