For questions related to user defined caching mechanisms, memoization, in particular.

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53
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5answers
3k views

What does the construct f[x_] := f[x] = … mean?

This question mentions "x := x = trickery". What does defining a function as f[x_] := f[x] = ... do and what is it good for?
36
votes
4answers
2k views

How can I implement dynamic programming for a function with more than one argument?

Dynamic programming is a technique for avoiding the repeated computation of the same values in a recursive program. Each value computed is immediately stored. If the value is needed again, it is ...
17
votes
3answers
707 views

How to clear parts of a memoized function?

I have a function of two variables, e.g.: f[a_, b_] := f[a, b] = something f[a - 1, b - 1] etc With the above code I used the concept of memoization to speed up ...
7
votes
3answers
3k views

Get polynomial interpolation formula

I'm attempting to get a polynomial interpolation formula out of Mathematica but I am absolutely lost. I stared out using ...
19
votes
2answers
527 views

Parallelize evaluation of function with memoization

I have a complicated function that I need multiple times, so I want to memoize it and have the first evaluation done in parallel. Unlike in my example below it's not a continuous function, so ...
12
votes
3answers
438 views

Using Memoization with a Mutable Object

In looking for a solution to this question, I ran across some old binary tree code by Daniel Lichtblau, reproduced below: ...
12
votes
3answers
275 views

Memoization of Rounded inputs

Memoization is a technique for improving performance by having a function remember its previous arguments. For example, f[x_]:=f[x]=mySlowFunction[x] will be ...
11
votes
2answers
495 views

Dynamic Programming with delayed evaluation

By using dynamical programming, we can save intermediate steps for recursive relations, as in f[n_]:= f[n] = f[n-1] + f[n-2] However, this only stores ...
12
votes
3answers
380 views

How to memoize a function with Options?

Consider the following modified fibonacci function: ...
9
votes
3answers
637 views

Improve speed for calculating a recursive sequence

I want to calculate following recursive sequence: $\alpha_{0}=0,\\ \cos(\alpha_{i})=\cos(\alpha_{i-1})\cdot\cos(\beta_{i})+\sin(\alpha_{i-1})\cdot\sin(\beta_{i})\cdot\cos(\gamma_{i}).$ In ...
4
votes
4answers
331 views

How to do memoization together with evaluation of a complicated function

UPDATE 2: much shorter version Given a list of paired indices {i, j}={{1,2}, {3,4}, …}, I need to first evaluate a rather complicated function test[i,j,x] (because ...
1
vote
2answers
67 views

Unintentional function memoisation via Dynamic

I needed to display edge labels of a graph in a way that allows the edge labels to be moved. ...