Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [compression]

The tag has no usage guidance.

9
votes
2answers
390 views

Efficient way to storage large lists in a file(s)

Let us assume that I need to storage in a file, or files, data with the following form ...
2
votes
1answer
149 views

How to zip folders

I know that one can archive data with Mathematica using: CreateArchive[source,path] I have a lot of folders (folder1, folder2,folder2 etc.) that I would like to ...
1
vote
1answer
41 views

Compressing TIFF figure with constant resolution

I need to compress the TIFF figure "p5"(originally around 25 mb) in to less than 1 mb or as small as possible with constant resolution of 600 dpi. ...
6
votes
1answer
181 views

Iconize a compressed image

I want to embed a compressed image in a notebook so that only an icon is visible (and not the whole image). The following procedure seems to work : ...
1
vote
0answers
27 views

CreateArchive[] without directory copy [duplicate]

CreateArchive["C:\\temp out\\"] The above creates a zip file containing directory temp out at level 1, but I require just the ...
6
votes
0answers
137 views

How to create TAR archive without top-level folder?

Mathematica has the handy CreateArchive function, which allows you to efficiently create a TAR archive from a directory. However, I see no way of specifying not to ...
11
votes
3answers
195 views

Support for low-complexity (compressible) lists

By "low-complexity list" I mean a list like the following: lcl = {17, 17, 17, 17, 17, 21, 21, 21, 21, 21, 21, 21, 21, 11, 11, 11, 11, 11, 11, 11} ...
5
votes
1answer
158 views

Decoding GZIP encoded Body, BodyBytes (ByteArray) and BodyBytesArray from URLRead

When calling the Stack Exchange API v2.2 using the new (Mma11) function URLRead we get a GZIP encoded Body in alternative formats: ...
9
votes
1answer
168 views

How to store data in a Mma SE question using hidden html-like markup?

Mathematica Stack Exchange accepts HTML in the questions, and therefore text such as <undefined rubbish> should be ignored when formatting the question for ...
19
votes
1answer
238 views

How to uncompress strings safely (without any evaluation)?

Compressed strings are often used to exchange Mathematica expressions on the Internet. It is, however, not easy to see what such expression will do after decompression. Resulting code can perform ...
25
votes
4answers
958 views

What's purpose of the new function BinarySerialize?

11.1 introduced a new function BinarySerialize, but I don't know what it can do better than the traditional method.Its behavior is very similar to ...
6
votes
1answer
227 views

How does - represent compressed data?

The Wolfram Blog article "The Semantic Representation of Pure Mathematics", by Eric Weisstein and Ian Ford (http://blog.wolfram.com/2016/12/22/the-semantic-representation-of-pure-mathematics/) has a ...
9
votes
2answers
220 views

Is there a way to create ZIP OutputStream ?

I want to write data to a file using compression. Is it possible to do that just in time (like in java ZipOutputStream). E.g. what I want: ...
0
votes
0answers
111 views

Import MDB in ZIP as ASSOCIATION

I have a zip file which contains an access database file (mdb format). How do I extract the database and the headers and convert them to association format? I know the command for doing that ...
12
votes
1answer
168 views

A weird issue with Interval[$MaxNumber]

Bug introduced in 9.0 or earlier and persisting through 11.0.1 or later From the Interval documentation: For approximate machine- or arbitrary-precision numbers ...
22
votes
2answers
1k views

What algorithm do the Compress and Uncompress functions use?

Compress and Uncompress are used internally by Mathematica to compress things like 3D data in notebook files - data that I'd ...
0
votes
1answer
108 views

How to zip a folder? [duplicate]

This straightforward approach doesn't seem to work: In[42]:= cmd = StringSplit@"zip -r ~/data.zip ~/test/*" In[43]:= RunProcess@cmd Related: How can I encrypt/...
12
votes
2answers
1k views

How to correctly import data zipped with the “deflate” algorithm?

I'm writing an importer for the GIFTI file format. The details of the format are not particularly important, but the basic idea is that it is a relatively simple XML file which includes binary arrays ...
6
votes
1answer
419 views

HOWTO encode/decode large chunks of Mathematica code/results e.g. for posting on sites?

At times, we as questioners would like to post huge Mathematica-expressions to websites (e.g. mathematica.stackexchange.com), or have an easy way to get such code from a site. Above a certain size, <...
8
votes
2answers
212 views

Compress uses too much memory and sometimes crashes the Kernel

Using Compress is a good idea to save memory when working with large expressions. The problem is that Compressing large ...
4
votes
0answers
135 views

Monitor progress of ZIP file extraction

Importing a ZIP file containing potentially many individual files in a (custom) format using Import[filename, {{"*"}, "Gaussian"}] takes quite a while. How can I ...
4
votes
0answers
1k views

Is there a way to use video codecs for avi files in Mathematica?

I would like to use Mathematica to create compressed .avi video files from image sequences. I read the documentation on .avi but couldn't find a solution. In the documentation it says: Internal`$...
0
votes
1answer
3k views

Union::normal: Nonatomic expression expected when using Uncompress

I saved a expresion to a file like this Export["file.dat",Compress@myExpression]; Then (i don't know why) when I import the file i get the compressed expresion ...
17
votes
4answers
2k views

Plotting data points: Optimizing size and visuals

The following problem is one that may have showed up to you while plotting a large data collection. Suppose you have a data set of say 1 million points. ListLinePlot...
14
votes
4answers
990 views

DataEncoding and compression in HDF5 format

I would like to export data in HDF5 format with Mathematica 9. The Mathematica manual about Import and Export of this format can be read here. As I'm dealing with large arrays, export often lead to ...
7
votes
2answers
926 views

DatabaseLink`: MySQL query with client/server compression

I'm trying to reduce transfer time when accessing rows of a mysql table over a network, where each row has a lot of data. Is there a way to enable client-server compression when accessing a mysql ...
3
votes
2answers
119 views

How to uncompress only the compressed elements in a matrix

I have data in a rectangular structure – something like matrix={{a,b,c},{d,e,f},{g,h,i}}. The problem is that some of the columns consist of uncompressed data and ...