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

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44
votes
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?
33
votes
4answers
1k 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
2answers
414 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 ...
16
votes
3answers
502 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 ...
12
votes
3answers
408 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
332 views

How to memoize a function with Options?

Consider the following modified fibonacci function: ...
11
votes
3answers
246 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 ...
10
votes
2answers
383 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 ...
9
votes
3answers
499 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 ...
6
votes
0answers
365 views

Increasing recursion speed in Hull-White trinomial tree calculation

First timer here and have been finding these boards very useful in learning Mathematica. I'm trying to implement a numerical procedure for the Hull-White trinomial tree in Mathematica. Despite using ...
5
votes
3answers
2k 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 ...
4
votes
2answers
156 views

Is it possible to `Protect` a dynamic programming process?

I wrote a function using dynamic programming to speed up the evaluation. For safety, I also want to protect this function. Take factorial for example: ...
3
votes
2answers
247 views

Problems with DumpSave and memoization

I defined a function that takes some time to compute using memoization: y[a_, b_, c_] := y[a, b, c] = First[$y /. NDSolve[.........] so that if I call y[a,b,c] ...
2
votes
1answer
170 views

tricky memoization

Let's say I have the NDSolve example for documentation involving splitting 2nd order into set of 1st order ODEs: ...
2
votes
0answers
76 views

SetDelayed and avoiding function calls through memoization [duplicate]

I am fairly new to Mathematica. I am working my way through a number of books. I have been looking at the use of SetDelayed and want to confirm that my ...
1
vote
2answers
57 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. ...
0
votes
0answers
57 views

When to use memoization concept in Mathematica? [duplicate]

I have recently learnt memoization concept. But I am not sure in what scenarios i need to use this concept. if someone can help me out with different scenarios it would help me a lot to develop a ...