Specific forms of data storage and file types external to Mathematica.

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23
votes
3answers
2k views

How to read data file quickly?

I have a tab separated value file with 10 million rows each of which has three tab separated values. The first value is a string, the second an integer, and the third another string. How to read ...
18
votes
3answers
1k views

Download xkcd Click and Drag comic

Inspired by the recent question about xkcd styled plots I started looking at xkcd again and I came across a comic titled Click and Drag. And if you do that, you start exploring a larger drawing. A ...
11
votes
3answers
406 views

Data of badly formatted file

Similar as in this question, I have to read in data from a file (exampleFile.txt) which is not so well formatted. Unfortunately, I cannot find a solution by myself. Since it is a bit complicated to ...
8
votes
3answers
313 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 ...
8
votes
1answer
370 views

Converting other C++ classes to MTensor in LibraryLink

Hopefully this will be a quick question + a quick answer: Say I have a C++ (or C) code using LibraryLink. I am using a library that defines a specific matrix class, as many numerical libraries ...
7
votes
1answer
278 views

Accidentally corrupted graphics (?) data of notebook — now it won't open

In the process of editing my scripts' variable names with a haphazard "replace in all open files" in my text editor, I accidentally replaced portions of graphics data in a notebook (and I believe this ...
7
votes
1answer
143 views

Organizing similar datasets using Contexts or otherwise

I often import several long time series to analyze something about a city. When I have multiple cities, I use contexts. As a simple example, ...
7
votes
1answer
299 views

Is it possible to construct a function to make a poor man's Mathematica database?

I have a function that is set up to write to a database with 10-20 standard variables with 10 fields each, but the application is going to a place where database access is not available. Can ...
6
votes
3answers
189 views

Organizing similar datasets using DownValues instead of Contexts

In his answer to this question, Leonid helped me find a way to programmatically generate contexts for holding sets of symbols with the same names. Perhaps a simpler way is to use ...
6
votes
2answers
482 views

Trying to extract information from an MDB file. Import is too slow

I am running a Linux box and as usual the documentation for this type of box is not great. I am trying to open up and extract and possibly include later on information from a "mdb" file. The file ...
6
votes
1answer
262 views

ESRI shape files

ESRI shape files (shp): importing the polygon data can yield a very large list. It is computationally intensive rendering the polygon. I have been trying to convert to ...
5
votes
1answer
450 views

Volumetric analysis from topological maps

I want to calculate the volume of fill required to level an area about the size of three foodball fields. The Department of Public Works in my city can provide me with topo data for the area. Their ...
4
votes
3answers
290 views

Plotting data with exponentials

I have some data with 19000 sublists such as : {" 7.9080000e+01 1.9283193e+04"} Where the first number is the value for variable ...
4
votes
0answers
129 views

Getting EPS imports to respect the original fill rule

One major problem in my attempt to answer to the CountryData flags question is that the way Mathematica handles filled curves differs from the way SVG and EPS style editors do. The latter two have the ...
3
votes
4answers
453 views

Importing or reading data in binary format 212

I have a binary data file in format 212, and I want to import the file into Mathematica. How do I read or import binary format 212? I almost have no direct experience of working with any binary ...
3
votes
3answers
323 views

Support for Compressed Sparse Column sparse matrix representation

Is there native support for Compressed Sparse Column (CSC) format for sparse matrices, like importing and manipulating them?
3
votes
1answer
564 views

How to create a histogram of annual events, such as cherry blossom time

I have calculated blooming and ripening times for a specific variety of plant, based on actual temperature data from over 40 years. I would like to create two histograms on a single axis; one for ...
2
votes
2answers
144 views

How to read non-standard-format data into Mathematica from a file

I would like to read non-standard-format data into Mathematica from a file. How can this be achieved? For example, how can I read the following text file of data into Mathematica: ...
2
votes
1answer
108 views

Read C-formatted hexadecimal numbers?

I have a lot of 32-bit numbers in hexadecimal symbolized as they are in C (for example, 0x1230abde). How can easily read these in Mathematica?
2
votes
3answers
219 views

What format to use to store expressions in database?

I am storing lists of expressions into a MySQL database. Each list is of form {_String, {_String, _Real}, _Real} What data format should each column of the ...
2
votes
1answer
104 views

Mean of Date variable data

I have hourly registered data as : ...
2
votes
1answer
157 views

Importing data from Excel for DateListPlot

I am importing data from Excel and plotting it with DateListPlot. My code is ...
2
votes
1answer
84 views

Import YAML file into Mathematica

Has anyone implemented the import of YAML data files into Mathematica? I suppose some sort of transformation into a nested list of rules would be the way to do it. Thanks
1
vote
2answers
195 views

Problem in reading data from a text file with two variables

I want to read in a data file, test.txt, in Mathematica. The file has the following content: ...
1
vote
2answers
97 views

What is the default file path used by the Put function and how do I pre-evaluate an expression to use in Put?

I have a problem of trying to store some output in an external file. In one note book I define a function f[x_]:=AdvancedCalculation, where this function generates ...
1
vote
1answer
170 views

Backward compatibility issues while DumpSaving Interpolation polynomials

I have bkwrd compatibility issues when I save my NDSolve result (which is an interpolating polynomia) using DumpSave from Mathematica 8 on Windows 7 and then try ...
0
votes
2answers
202 views

Import large amount of data with time stamps

I have a large data file (150 000 lines) which I want to import in Mathematica. The first few lines look like this ...
0
votes
1answer
100 views
0
votes
1answer
162 views

3D Plot of .txt File of the Surface Plotting Variety

I'm having a bit of trouble. I've seen other questions answered on here about how to 3D plot data from .txt files of the format: x y z x y z x y z Which works ...