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

learn more… | top users | synonyms

7
votes
3answers
822 views

Efficient image Import

I have several sets of 20 images I need to import. Each time they have different categories. "Name"<>"Cat"<>"No" Electric B 1 for example. I need to create lists that contain the images ...
4
votes
2answers
350 views

How to save a web page in mathematica?

For a given web page http://www.nytimes.com/, is it possible to save it as : first: only HTML(within css) second: more elements(include pictures and so on) just like what a browser can do. ...
5
votes
1answer
1k views

Combine multiple PDF files into one document

I have multiple single page PDFs I'd like to join together into a single file. (Obviously I mean the file format and not the probability distributions here!) I'm aware of free online services such as ...
4
votes
2answers
2k views

Reading in scientific notation from C++ to Mathematica

With a text file with entries formatted as (output from C++): f[38.67] = -2.5387862698183892298317350539374412777263289550697e-05; ⋮ Is there a way to read this ...
4
votes
2answers
5k views

Importing from Excel

I'm trying to import a matrix from Excel to Mathematica. My code is: Import["desktop/stproj.xls", "xls", data, 1] The output is some weird stuff about population ...
2
votes
0answers
169 views

Errors importing UTF8 file to mathematica

I'm trying to import this file: Import["https://dl.dropboxusercontent.com/u/35192406/jarlaxxe_tweets.\ csv", CharacterEncoding -> "UTF8"] But I am getting ...
1
vote
1answer
887 views

How to set path of IMPORT from excel into Mathematica?

I was able to IMPORT from excel data at the start of my project when both the .nb and EXCEL XLS files were sitting in MyDocument (or some other location), but upon moving both files into my Dropbox ...
5
votes
0answers
980 views

Import Large Excel File

Currently, I am working on a large time series dataset, which contains 928,586 rows and 35 time intervals in columns, in excel format (.xlsx) and using Import to ...
4
votes
1answer
283 views

How can I colorize an imported model?

How can I colorize an imported model from for example 3ds max? I'm trying to find the way to colorize a 3D plot from an imported model with something like this: ...
3
votes
3answers
409 views

Import data from first/last 100 rows of a file

If one wants import data from the first three rows of a file "myfile.data", one can use the command Import["myfile.data",{"Data",{1,2,3},All}]; However, if I ...
3
votes
1answer
469 views

ReadList with header and foot lines

I want to do some large data analysis, and i want to be able to import files in a fast way. I tried Import, but it is quite slow; ReadList takes half the time. This is the code I was using: ...
3
votes
1answer
806 views

How do I read a CSV file and remove comments from it

I have very recently started using Mathematica 9.0 Home Edition and am trying to understand it as best I can so please be tolerant ;). I have a file of data (sugar.csv) which contains blood sugar ...
3
votes
1answer
446 views

Running external pdflatex command and importing the generated PDF document

There have been a couple of questions about incorporating labels and equations that were typeset in $\LaTeX$ into a Mathematica notebook. Ideally, this requires running ...
2
votes
1answer
78 views

Registering/detecting an importer by file name extension

I've developed an importer and exporter for FreeSurfer's MGH/MGZ file format; the specific format isn't important, but I was ...
2
votes
2answers
155 views

Animation of moving rectangles in 2D from data file

I am not very familiar with mathematica but I know the basics so I thought I give it a try. For a project I have to animate rectangles moving around in 2D (later also 3D). The data come from a C ...
2
votes
4answers
3k views

Plotting a large number of data points

I would like to know how to plot when I have a large number of points (arround 600) in a specific format: ...
1
vote
1answer
536 views

Making a ListVectorPlot3D from data in an external file

I have a .dat file with six columns: {x y z vx vy vz}, where x, y, z are space coordinates and vx, vy, vz are the vector components. How can I use this file to get ...
1
vote
2answers
372 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 ...
-3
votes
1answer
476 views

import Excel sheets by name

I'm importing data from Excel. It appears that the sheet number needed in the Import statement is taken from the order that the sheets appear in the open Excel file. I need to import 2 of the sheets ...
32
votes
3answers
2k views

How to do http POST in Mathematica?

The Import command lets you do a HTTP GET from a URL, like this Import @ "http://merkosoncampus.com/wp-content/uploads/2011/05/higgs-boson.jpg" This sends an ...
24
votes
1answer
3k views

Programmatically retrieving e-mails from a remote server

Mathematica has a function for sending mail (SendMail) and can import the MBOX format. But what I'd like to do is ...
19
votes
3answers
1k views

Finding a function that fits the shape of an image

How can I find a function that fits the given shape of an image? Or instead extract a point set from the shape and then find an interpolating function fits the shape. An example image is attached.
19
votes
2answers
781 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 ...
12
votes
3answers
3k views

Excel Headers --> Mathematica

I have a large Excel .xls file. Miniature version shown below: (formatting should appear as two columns...) ...
8
votes
1answer
186 views

How to use RunProcess to import external function?

I have a functions written in an external language called GO. How can I quickly load them into the kernel for use as Mathematica functions? The two ways I've tried are with MathLink and LibraryLink ...
10
votes
4answers
467 views

Exporting data extensions in fits file

Context In Astronomy the de facto standard for images and data is FITS. I would like to export heterogenous data sets into a single fits file. Attempt I am ...
7
votes
1answer
300 views

Import iTunes xml data and convert it into a dataset or table

I have an xml file with song data from iTunes (https://dl.dropboxusercontent.com/u/1012958/iTunes%20Library.xml) and I'd like to import it to Mathematica to do some statistics. I get an XMLObject like ...
12
votes
3answers
1k views

How can I transfer mathematical expressions between Mathematica and Maple?

Is there a simple way to copy mathematical expressions between Mathematica and Maple (or at least in one direction)? I mean only expressions built from numbers and predefined mathematical functions, ...
10
votes
2answers
252 views

How to extract a specific element from EXIF photographic metadata?

It's now possible to import photographs into Mathematica and import the EXIF data at the same time: i = Import["ExampleData/coneflower.jpg", "ImageWithExif"] ...
8
votes
2answers
298 views

AJAX-style HTTP calls triggered by a variable change

I'm trying to create a dynamic InputField that would autocomplete the address as I type it into the field, by calling Google Maps' GeoCoding API on every change of ...
8
votes
2answers
1k views

Import Fortran unformatted binary

I have an unformatted binary file generated using the Compaq Visual Fortran compiler (big endian). Here's what the little bit of documentation states about it: The binary file is written in a ...
8
votes
2answers
4k views

Import selected columns from a tab delimited text file

I have a very huge file (1GB) from which I desire to import only the 5th column. It is a tab delimited text file with a .txt extension. Can you please help me with ...
7
votes
1answer
422 views

Converting XMLElement objects to plain text

Short version: How can I convert an XMLElement that represents part of a HTML document to plain text? Long version: The more general problem is extracting ...
6
votes
1answer
207 views

Reading specific entries from a CSV file

This question is related to the following: Speeding up Import and Export in CSV format Stream CSV files Reading periodic elements from a large file I have a set of very large CSV files (a few ...
11
votes
4answers
1k views

Import[ ] drops leading zeros from data when importing a CSV file

I need to load data from the CSV file shown below. Import[ ] drops the leading zeros in column 3 when it imports the CSV file, but they are security identifiers, and I need them. ReadList[ ] ...
8
votes
3answers
1k views

Skip header lines on import

When importing a data file what are the comment symbols for Mathematica? That is, given a file like this blabla bulbul 1 2 6 54 7 ... .. what symbol do I have ...
8
votes
1answer
592 views

How to properly DumpSave & Get Global`s symbols inside packages while not touching Global context?

For efficiency reasons I prefer to use DumpSave instead of Save. For ease of access I prefer to save symbols in ...
6
votes
1answer
396 views

Operations on online files via public URL access

I need Mathematica to access an online public directory via some URL (fake in this case) http://example.com/images and perform operations similar to those Mathematica can do on OS directories and ...
5
votes
2answers
273 views

Sorting a large file

I have some huge logs, which are text files, containing up to a million rows each, and I need them sorted. Because trying to import one obviously makes Mathematica run out of memory, we must rule out ...
5
votes
1answer
791 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 ...
4
votes
2answers
210 views

Importing multiple images for machine learning classification

I want to create a ML classifier using images just like this example. I have two classes of images in two different folders. Is there an easier way to import all images from both folders rather than ...
3
votes
2answers
85 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 ...
20
votes
2answers
427 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 ...
12
votes
2answers
594 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
563 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. ...
7
votes
1answer
853 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
1k views

When do I use Mathematica, when do I use Gephi, and how do I use them together?

Mathematica has great operations for analyzing graphs but when the graphs are a bit bigger, Gephi seems to be more efficient (at least on my computer) at drawing and analyzing, i.e. visualizing the ...
5
votes
1answer
169 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 ...
4
votes
1answer
152 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 ...