Questions tagged [compression]
The compression tag has no usage guidance.
41
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57
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How to improve Burrows-Wheeler Transform performance?
I have implemented the Burrows-Wheeler Transform as below:
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- 25.6k
1
vote
1
answer
63
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Compressing a file's name string
I was working with files where each name records a lot of information about what is in its respective file and wanted to compress it a little bit. So I wanted to change it's 'base'.
And I noticed that ...
- 94
1
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0
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60
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Speed limitations when importing files from .zip archive
I have .m files with a total size of ~500 MB. Their import is really fast, within less than 1 second. In contrast, I may pack them into a .zip archive. The importing then is much slower, ~20 s. ...
- 5,887
3
votes
1
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130
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Optimized GIF 20s for 85kb for Mathematica Code Demonstration
I’m new here this is my first post on Stack Exchange. In the thread below, I see that a GIF file is highly optimized (20s for 85kb) with no noticeable compromise in resolution. It appears to be the ...
- 33
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Updating a compressed Boolean 1D array, without uncompressing
I iterate through a process, each time generating a new number between 1 and a very large number (10^15 or larger). I am waiting for any number to repeat.
Clearly a 1D Boolean array (starting out all ...
- 1,225
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0
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165
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OpenRead with Method->"GZIP"
Aim
I'm trying to "Low level" read data from a large "GZIP" file as an InputStream.
Previous answeers
I ...
- 139
5
votes
1
answer
327
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How can I compress DICOM images?
I have 193 dcm files in a folder. I will like to combine these images into .dcm.gz format (e.g. images.dcm.gz) and I was wondering how this could be done in Mathematica. Thank you in anticipation of ...
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6
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1
answer
311
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How to compress a string in Mathematica so that it can decompressed in python
I need to compress a string into some format so that I can pass it along on the command line and avoid writing it to file (which would require locking files to prevent simultaneous writes so I prefer ...
- 4,591
0
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1
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140
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Import CSV data from internet to mathematica [closed]
This Link has data in CSV format for 2015 and other years. I would like to get the data for 2015 (by clicking on 2015) but the CSV data format has more rows than Excel can handle and therefore the ...
- 6,233
2
votes
1
answer
41
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Compression results in unpacking of integers but not reals
Consider the following;
Pack some integers.
In[287]:= Clear[p5i, p5ic, p5icu, p5r, p5rc, p5rcu]
In[288]:= p5i = ToPackedArray@Range@5
Out[288]= {1, 2, 3, 4, 5}
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- 790
5
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1
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174
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Import ZIP file options broken in Mathematica 12.2.0
I am trying to read a zipped table, which has its entries separated by colons. In Mathematica 12.1.1 (and earlier) this worked well with the following command:
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- 1,246
4
votes
2
answers
176
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How to deal with zip files in the wolfram cloud?
I have a zip file in the cloud but I can't seem to unzip it!
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- 31.6k
14
votes
0
answers
784
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Is it possible to use better modern compression algorithm instead of zlib in Mathematica for efficient data saving and loading?
Some backgrouds of my problem:
Recently, I had a heavy data analysis work to do. Each day I got thousands of csv Files(colums with different datatype) with total several Gigabytes. I have to ...
- 17.2k
1
vote
0
answers
276
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How to uncompress zip file fast with Mathematica?
What is the fastest possibilty to uncompress zip files with the following content?
It containes numbered ".png" files, corresponding ".header" files (theses are text files) and a file called "...
- 2,396
11
votes
2
answers
909
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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
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- 2,537