Questions about RAM usage, including optimizing memory use, avoiding and fixing leaks and releasing unused memory.

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2
votes
0answers
136 views

Clearing memory of a subkernel in a Do loop

I have a Do loop, which saves data directly to a .txt file. However when I leave it running for long periods of time the RAM ...
2
votes
1answer
72 views

Strange response with dynamic texture and MousePosition

I built a cubic, then use MousePosition together with GUIScreenShot to take a floating region with fixed size (200*200) on the ...
1
vote
0answers
155 views

CUDALink ran out of available memory

I have a problem with automatic GPU memory management when using CUDA. The situation is the following: I create a simple CUDA function that operates on a 2D array (image), which does not take much ...
2
votes
2answers
196 views

How to pick out specific parts of the solution of a differential equation efficiently?

I'm trying to solve a set of differential equations (in parallel) and then select specific parts of the solution. What I have at the moment (see below-I've simplified the differential equations, in ...
2
votes
3answers
121 views

Accessing temporary value of a Nest evaluation

The function Nest[] must store the temporary values in the memory somewhere (those values that would form the entries of the list which is returned by the ...
5
votes
1answer
350 views

Clear and Unset doesn't free memory

Example: Try this example only if you have > 4G ram d = 2000; f[x_, y_, d_] = Sum[Subscript[a, i, j]*x^i*y^j, {i, 0, d - 1}, {j, 0, d - i}]; Then ...
8
votes
1answer
170 views

Where is my memory? — LibraryLink never returns the memory

This is an example LibaryLink code from Mathematica documentation, which takes an integer and return an integer list: ...
4
votes
2answers
292 views

Memory efficient generation and selection of tuples

The short of this question: I need to find a bunch of n-tuples of {0,1} which do not fail to satisfy a set of (non-linear polynomial) equations, without hogging up all of my memory by trying to ...
7
votes
2answers
156 views

Giving JLink Huge Memory by Default

I have noticed that Mathematica makes use of Java by way of JLink, for example, in the extensions such as DatabaseLink and (I think) RLink. It also seems like Java is a first-class citizen for writing ...
2
votes
1answer
174 views

Paging RAM in case of memory shortage issue

Is there some way in Mathematica where I can issue execution of some command with letting Mathematica use my hard disk in case it is short of RAM. It will drastically reduce the speed but I am fine ...
0
votes
0answers
107 views

How can I revise my program to avoid “No more memory available”? [duplicate]

I have a program for calculating a type of list. ...
0
votes
0answers
30 views

Keeping memory to reduce the running time of recursion [duplicate]

I am using the following recursion in Mathematica to compute W[n, 1, s] for given n and s: ...
1
vote
1answer
96 views

Memory handling by ConstantArray

I noticed the following issue when using ConstantArray: a = ConstantArray[0., {10000, 100}]; ByteCount[a] (* 8000152 *) Then ...
1
vote
1answer
132 views

Running out of memory using FindMinimum with ParametricFunctions

I am running a pretty large optimization problem which actually consists of an outer an inner optmization problem. I use ParametricNDSolve for solving a ODE system. When the optimization is done, ...
5
votes
1answer
73 views

How to relate memory usage with occupied positions of SparseArrays?

What is the relation of memory usage of a SparseArray and the number of its occupied positions? Let's say you build a 100.000.000 by 10 element SparseArray. And fill the two position 1/1 and ...
1
vote
0answers
120 views

FindRoot runs out of memory in Windows but not on Mac

I am using FindRoot to find solutions to a large, highly oscillatory equation which I generated using other code. When I run ...
2
votes
1answer
397 views

Getting MemoryAllocationFailure from NIntegrate

When numerically calculating a double integral using NIntegrate over an infinite domain (with all options at their default), Mathematica 7 calculates my integral ...
2
votes
0answers
242 views

Is mathematica storing information it shouldn't store?

I'm seeking to find solutions to a numerical integration with a large set of parameter combinations (basically, I'm doing a brute parameter sampling). Yet, I believe the memory of the computer is ...
9
votes
2answers
641 views

Why does this simple program leak memory?

I have a simple Mathematica program which writes some plots to image files for later conversion into a movie. Unfortunately, the program leaks so much memory that it quickly exhausts all 12G of RAM ...
2
votes
1answer
62 views

PolynomialRemainder memory

This calculation makes the kernel crash because it needs so much memory. Thoughts on how to get around this? ...
5
votes
1answer
131 views

Is it possible to lower the bitwidth of (floating point) numbers?

The answer to this question will most probably be a definite no. Nevertheless, I would like to know whether it is possible to represent reals in the memory on less than the standard 32 or 64 bits ...
2
votes
0answers
181 views

Project Euler (memory and speed issues)

Let n be a positive integer. An integer triple (a, b, c) is called a factorisation triple of n if: 1 ≤ a ≤ b ≤ c a·b·c = n. Define f(n) to be a + b + c for the factorisation triple (a, b, c) of n ...
7
votes
1answer
502 views

Mathematica memory management for large arrays

I have come across a weird phenomenon in Mathematica when dealing with large arrays. When generating a list with all the possible subsets of three elements of another list (thus having elements which ...
3
votes
2answers
200 views

Storing result from nested Table in a File for further computations

Consider the following: Table[Table[x = 20; y = 30; 2 i x + 3 j y , {i, 10}], {j, 3}] Suppose I want the result of this nested Table to be stored to an ...
0
votes
1answer
223 views

Why does memory run out when adding same-sized matrices in a loop?

I have written a module that it generates a 101x101x51 zero matrix at first. At every iteration, it generates a list by funct1 and based on this list, if list is empty it gives the previous result. ...
17
votes
3answers
602 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 ...
14
votes
1answer
472 views

Efficient code for tallying entries in very large lists

I am dealing with data sets containing tens of millions of (hashable) entries and simply using the Tally function to count the frequency of each unique list element ...
5
votes
1answer
226 views

Processing and storing a graph with a large number of vertices s.t. k-hop neighborhoods are efficiently retrievable

I have an unweighted, undirected graph $G$ with $(v_1, ..., v_N) \in V$ vertices, where each vertex in the lattice represents a string of some length ($\leq 200$ characters), and I need to construct ...
0
votes
0answers
78 views

Is there a way to ask Mathematica for the RAM installed? [duplicate]

Possible Duplicate: How to find out the (current) free memory on the system? Do we kwow of a function to get the installed amount of physical system memory RAM of my Windows PC?
19
votes
2answers
662 views

Why does ImageData need four times more memory?

Background We are dealing with very large TIFF image files that are imported, processed and exported using Mathematica 9.0.1. Many of our algorithms only work with an array representation of the ...
4
votes
1answer
212 views

Why does MemoryConstrained not abort when memory limit is exceeded?

I thought I had an idea that might lead to an answer to @yohbs' question, but as I was trying to check out the usage of MemoryConstrained[expr,b,failexpr], I ...
5
votes
3answers
359 views

How do I find the amount of free space on disk?

I know a workaround, where one calculates sizes of all files and then you subtract this from your default space, but is there any direct way to do it? Simplicity and speed are important. There's the ...
12
votes
2answers
1k views

How do you deal with very large datasets in Mathematica?

This question is in two related parts. The first is about dataset size, the second data wrangling. Part 1: I've built a naive Bayesian classifier on Mathematica. It uses ...
4
votes
1answer
576 views

Forget past outputs to free memory

While tinkering with a notebook that loads a large chunk of data in memory, I noticed that if I run it multiple times, the past chunks reside in memory. I understand that the reason (or one of) for ...
3
votes
1answer
161 views

How to efficiently take complement of two big lists?

I have a giant list l1 and some smaller lists l21, l21, ..., ...
7
votes
2answers
761 views

Memory running out generating ContourPlot3D

The code below ...
2
votes
1answer
621 views

NDSolve runs out of memory

I need to solve a second order ODE numerically. The ODE depends on two parameters (a,b). Things work fine when 'a' is small, but for large 'a' the solutions are oscillating rapidly and Mathematica ...
23
votes
4answers
1k views

What is the fastest way to count square-free words?

Background A word is a string of letters in an alphabet. A square-free word has no adjacent repeating substring. For example, (in the ternary alphabet of {0,1,2}) the words 00, 012121, and 0212012021 ...
7
votes
2answers
219 views

Clean up list of partial outputs for memory

Context I run long Mathematica sessions; sometimes I have Output up to Out[3000+]. Hence I would like to be able to clear out some previous outputs which do use lots of memory. Attempt I am aware ...
4
votes
2answers
291 views

Implementation of builtin function Fold

In the documentation for fold, it says Fold[f,x,list] gives the last element of FoldList[f,x,list]. But this is surely not the way it is implemented, right? ...
1
vote
1answer
178 views

Using block or module to free cache

I'm writing some code at the moment that schematically looks like: (set initial conditions for some differential equation for given parameters (M,R,...)) ...
20
votes
4answers
2k views

Plotting large datasets

I have a lot of data (e.g., 64x8192), to plot and it consumes too much memory (more than 2 GB) causing Mathematica to return "no memory available". For example, ...
11
votes
1answer
491 views

Space-efficient null space of sparse array

I have a roughly 100,000 × 3,000 matrix (as a SparseArray) that I'd like to find the kernel (null space) of. It has about 500,000 nonzero entries, all -1 or 1. ...
23
votes
1answer
3k views

Finding long strings of identical digits in transcendental numbers

Introduction Describing the three main streams of present-day mathematical philosophy (formalism, Platonism and intuitionism) in a well-known book, The Emperor's New Mind, R. Penrose says: ...it ...
11
votes
2answers
300 views

Memory leak in FE?

A very abridged example of what was originally a major leak ...
8
votes
1answer
182 views

Reducing the memory footprint of lists of machine numbers

I have a large 1D dataset of double precision numbers that are stored in many external database files. In order to load the whole dataset into Mathematica 8 I iterate over the files ...
22
votes
2answers
1k views

Debugging memory leaks

I've written my incredibly complex, incredibly elegant analysis function, that works great on small test data. But when I run it on my real (bigger) data set it keeps running out of memory. It turns ...
22
votes
3answers
986 views

How to place an image inside a notebook, with the minimum memory footprint?

When creating a notebook with images, like photos, the file tends to quickly get big, which makes it difficult to use the notebook format for training material containing a lot of images. Are there ...
19
votes
3answers
1k views

Does parallel programming use up large quantities of memory in Mathematica?

When I start Mathematica with a fresh kernel and load a program I am developing to analyze biology data, the amount of used system memory is 1.9 GB (free memory is 14.5 GB). These memory values are ...
7
votes
1answer
681 views

Memory not freed after running Clear when using a Table

When I'm creating large lists with Table I see the memory footprint increasing. ...