Questions about getting data, files, images etc. from various formats into a form that can be read, tranformed and manipulated by Mathematica

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5
votes
1answer
910 views

Efficiently exporting many images as a video

I have many .gif images and I would like to export them as a single video file (I prefer .mov, but any video format is fine). But what if I have several tens of megabytes of .gif images? Is it ...
3
votes
2answers
98 views

Most efficient way of splitting a file into length-prefixed blocks

Let's say I have a really big file (>100MB) that consists of length-prefixed blocks, i.e. the first byte of each byte block indicates the length of the rest of the block. This is a simplified example ...
21
votes
2answers
473 views

Is Compress[] compatible between different Mathematica versions?

Compress[] was introduced in version 6 of Mathematica. It gives a compressed version of expressions represented as a string of ASCII characters. It preserves more ...
13
votes
4answers
395 views

Unencoding encoded URLs in a function

Is there a built-in function for decoding encoded URLs in Mathematica? I would like to convert an encoded URL, for example ...
12
votes
2answers
689 views

Parsing a CSV file using Interpreter

The new Interpreter functionality in version 10 looks like it has the potential to make parsing custom data formats very easy. I'm trying to create a CSV parser. ...
10
votes
1answer
632 views

How to import date (YYYY-MM-DD) data from a file?

I have a file with data in form {date, value}: 2010-05-19 17 2010-05-20 20 ...
9
votes
2answers
1k views

How can I animate a set of points imported from file?

I have an external program which generates a set of data - X points at the time t1, X points at the time t2 and so on. These points are stored in CSV file and I can change the format if necessary. ...
8
votes
1answer
120 views

Is it possible to move .mx file from one server to other?

I have mathematica file in one server along with .mx file. Is there any way to move the .mx file from one server to other such ...
8
votes
1answer
156 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
924 views

Import file from FTP site

I would like to Import files from an FTP site. The code below works on a test site: file = Import["ftp://test:test@ftp.secureftp-test.com/pigs.xml"]; But when I ...
6
votes
1answer
227 views

How to use Get on a folder

In the documentation for Get it says: If the file found by <<name is a directory, the Wolfram Language will try to ...
6
votes
1answer
2k views

Reading csv/xlsx data into Mathematica with column headings as list names

It's old question. However, I could not find satisfactory answer. Decided to post this question. I have a .csv file with column heading. How can I import this ...
4
votes
2answers
197 views

How can I encrypt/decrypt a directory?

I'd like to use Mathematica 10's new Encrypt and Decrypt functions to secure files and folders on my mac. Here's what I have so far but something goes wrong along the way, since by the end of this ...
4
votes
1answer
226 views

mathematica use too much memory to Import large dat file

Err... When I try to Import a .dat file by dat = Import["D:\\TIEGCM\\solar_input\\omni_m_all_years.dat", "Table"]; or ...
4
votes
1answer
186 views

Importing malformed XML: Import[… “XMLObject”] vs ImportString[…, “XML”]

It appears that Import[ url , "XMLObject" ] is more forgiving of improperly formatted XML than ImportString[ string, "XML"]. For ...
4
votes
1answer
255 views

How to transform a DumpSaved .mx file to .m file conveniently?

I have many DumpSave-d .mx files under a directory. They are generated under Linux. The .mx ...
3
votes
2answers
125 views

Importing CSV with multiline text fields

Here is a valid CSV: a1,b1,c1,d1,"e1 e1 e1" a2,b2,"c2 c2 c2",d2,e2 It has two rows and five columns, and contains two fields with embedded CRLF. (See the CSV ...
3
votes
1answer
390 views

how to delete specific data from text file and then update it

I have a large text file. I read data from text file one at a time and check whether data agree with my condition. If not I want to delete that data in text file and update it. For example say my ...
3
votes
3answers
3k views

Import specific data from Excel to make a plot

I need some help with this: I have imported data from an Excel file and I need to make a contour plot of it. The data are in table-like form. Here is a sample of the first few 'rows': ...
3
votes
1answer
484 views

Mathematica - set end-of-line characters when importing

I have a plain text file of tab-separated values that was created on a Windows machine. I want to import it into Mathematica on a Mac. ...
1
vote
2answers
1k views

Can I improve the importing speed of Excel data?

I have data in an Excel spreadsheet that has 4 rows and 1,000 columns. I am using Import as follows: ...
9
votes
2answers
276 views

Working with Java hashmaps from Mathematica

I'm using J/Link to access data from an external Java program. The data are represented as a ConcurrentHashMap (see the official specification here). ...
8
votes
1answer
156 views

Reading a HDF file im Mathematica

Bug introduced in 8.0 or earlier and persisting though 10.2 On OS X, the problem is present in 9.0 but not in 10.0, 10.1 or 10.2. I am trying to read a HDF file in Mathematica 9 on OS X and get ...
7
votes
1answer
239 views

Incorrect result while using SemanticImport for CSV file import

I might use this incorrectly. I want to use a .csv file that (as list) looks like: ...
7
votes
2answers
937 views

Why does importing a URL fail the second time and produce a FetchURL::conopen error?

I have Mathematica code that uses Import[] to download URLs. I noticed that first time I use the Import[] command it works. ...
7
votes
3answers
240 views

How can I read in specific information from a TeX-file?

I have several TeX-files and they contain information of the form ...
6
votes
1answer
326 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
3answers
198 views

Is it possible to Import urls not type “”

These days I often copy urls from Internet Explorer's address bar. When I paste the url into a Mathematica cell it is neither a string nor a expression. ...
6
votes
1answer
282 views

Importing images from the web using ImportString & URLFetch

I can bring images from the web using the Import command like this: Import["http://blog.wolfram.com/wp-content/uploads/2008/06/se-30.jpg"] Sometimes the web ...
4
votes
1answer
273 views

Importing FITS file from HEALPix

I am trying to read FITS file created by HEALPix software. The file contains a spherical map of a scalar field. There is the online support on how to use the file in IDL, but not for Mathematica. I ...
4
votes
2answers
172 views

Workaround for Import not supporting the \leqslant TeX macro

$\{A\leqslant x\leqslant B\}$ Copy the code into Notebook, and you'll lose the less sign, this can be rendered well in ...
3
votes
1answer
156 views

Run Command Not Executing Node

How do I make the following command work in Mathematia? Import["!\"C:\\Program Files\\nodejs\\node.exe\" -p console.log('test')", "Text"] I don't get any output ...
3
votes
2answers
208 views

Why are dictionary keys reordered upon JSON import?

After importing a JSON file, Mathematica changed the order of the fields. For example, I downloaded a sample file from: http://api.openweathermap.org/data/2.5/find?lat=55.5&lon=37.5&cnt=10 I ...
3
votes
2answers
278 views

Speeding up TIF import

After trying to import a $\approx 2$ GB TIF file with the Import command, I noticed that the process takes $\approx 15$ minutes or so, which seems excessive, especially when compared to other software ...
3
votes
2answers
1k views

3D scatter plot from a txt file

I have a txt file with space-delimited x, y, z coordinates of several points. The points are organized into groups of unequal size; the groups are delimited by skipping a line, like this: ...
3
votes
2answers
442 views

Extracting a single layer from a SHP file

I have an ESRI ShapeFile (SHP) that I've loaded. It has a number of layers which I can see the names of by using: Import["file.shp", "LayerNames"] I get ...
2
votes
1answer
56 views

Import tabular text data

I have a text file created with a bash script I wanted to read the data avoiding the first line. I have written few dirty codes, but I wondered if anybody can do it in fewest possible nice one ...
2
votes
1answer
514 views

How to work with 3D images of STL format

After importing a 3D image of STL format, my possibilities in regard to "3D Volumetric Image Processing" seems rather limited. All examples are given with TIFF files. Is there a way to convert from ...
0
votes
1answer
76 views

Package to read in data from excel files

I want make a package to add a function to Mathematica that reads all excel files is the working directory that is set after the package is loaded. ...
0
votes
1answer
66 views

Elegant ways of solving this file batching task

There are a batch of data files in a folder (dir = "D:\\Documents\\datadir"), each of which consists of a list of data items, one per line. Each data item is a pair ...
0
votes
1answer
224 views

How do I upload a graph as an adjacency list and find the betweenness centrality?

I have an undirected simple graph in a .txt file formatted as an adjacency list like this: 100 200 200 300 300 400 500 600 700 800 900 ... Every number is a node ...
0
votes
0answers
255 views

Determining if a point is inside or outside a 3DS (.3ds) or 3DS MAX (.max) object? [duplicate]

Imagine I import some 3DS (i.e. 3D studio) file (http://reference.wolfram.com/mathematica/ref/format/3DS.html) or a 3DS MAX file. How could I place this model (say, the 747.3ds file in the ...
8
votes
1answer
262 views

Understanding `Paste` and how to get a string from the Clipboard to use with `ImportString`

Trying to work on this question I got distracted by my first naive attempt of copying the data and then typing dat = ImportString[Paste[], "Table"] ...
8
votes
1answer
641 views

Importing Excel Spreadsheet containing Array Formulas

Has anyone had any success with importing an Excel Spreadsheet holding an array formula into Mathematica? The Syntax I'm using is ...
7
votes
1answer
143 views

Using Differences on data: trouble with floats and doubles

Consider the following data set (after I have run FullForm), which is imported from a file (stored typically as 10.040): ...
7
votes
1answer
2k views

Import DCD (CHARMM/NAMD binary trajectory) file

How can one import the coordinates stored in a binary CHARMM/NAMD DCD file? This is the structure of the file: ...
6
votes
2answers
133 views

Possible memory leak when importing JSON

Bug introduced in 10.0 and persisting though 10.2.0 This problem that I would like to resolve is how to free memory used Import a file when the file is no longer in use. I have a project in which ...
5
votes
2answers
2k views

Converting numbers to integers

I've read the available documentation but I still haven't found an NumberForm -> Integer function yet. No result in this site's search, either. Does it exist? ...
5
votes
2answers
557 views

How to test if file exists and stop

At the moment I'm using > ...
4
votes
3answers
327 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 ...