Questions about getting data, files, images etc. from various formats into a form that can be read, tranformed and manipulated by Mathematica
2
votes
1answer
197 views
How to solve issue with exporting / importing data to and from Excel
Background ( simplified ):
When I export data to Excel like
...
5
votes
2answers
246 views
7
votes
1answer
642 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:
...
8
votes
3answers
542 views
Importing HDF5 with compound data
I am looking to Import HDF5 data with compound data. It appears, at least from what I read, that Mathematica 8.0.4 (and previous versions) does not support reading ...
10
votes
1answer
151 views
Exporting and reimporting a list of lists changes the dimensions
Could anyone explain to me what in the world is going on here and please help me in reading in dummy.dat properly?
...
3
votes
1answer
401 views
Stream CSV files
Ram limitations make import impractical for large CSV files. Is it possible to Stream CSV correctly?
...
12
votes
2answers
1k views
Importing a large Excel file
I'm trying to import a simple Excel file containing 94,000 rows and 52 columns of various types, mostly Reals. It's a 38-MB file. I get this super helpful error ...
25
votes
5answers
2k views
How can I extract data points from a black and white image?
Consider the following graph (source):
Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they ...
6
votes
1answer
1k views
How to extract sample values from an imported WAV file?
Suppose I read a file with
B = Import["something.wav"]
Now how can I obtain a list of sample values?
14
votes
2answers
257 views
How to load thumbnail, not image?
Is there any way to import only the thumbnail of an image instead of the full image? I frequently work with lots of images and it would be nice if the contents of a directory could be quickly ...
3
votes
2answers
2k 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 ...
8
votes
1answer
264 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 ...
19
votes
2answers
689 views
Extracting values from nested rules in JSON data
I have been using Mathematica to analyse some data from the StackExchange API. It is conveniently available in JSON form, which Mathematica interprets as replacement rules. However, some of the rules ...
21
votes
3answers
634 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 ...
6
votes
3answers
172 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 ...
7
votes
1answer
112 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,
...
15
votes
1answer
282 views
Importing Zip files
Mathematica can import zipped files automatically, but when the content of the zip file it's another zipped file, I just get the list of files in the second zip:
...
2
votes
1answer
218 views
Mathematica Import functions fails for data download from website
I am trying to download some data from a website that uses "java enabling" to tell me that I cannot download the data. Using
Import[ "website...", "Data"]
I get
...
4
votes
1answer
522 views
Difficulties with Importing PDFs in Mathematica
I am trying to import a group of PDFs that I have downloaded (it is in the realm of 1,000+). They are a group of doctoral dissertations that I'm trying to automatically extract bibliographic ...
9
votes
6answers
805 views
How do you skip missing data values in a data file?
In scanning through a simple imported file of weather station data, some dates have missing data.
What is a test to use to check whether a datum is valid? I tried ...
11
votes
3answers
311 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 ...
14
votes
1answer
665 views
How to manipulate web pages on Mathematica?
I wanted to input some data on this page through Mathematica:
http://www.fundamentus.com.br/buscaavancada.php
Then I would press the "buscar" button also through mathematica coding and get the ...
11
votes
1answer
306 views
Release the web camera after using CurrentImage[]
CurrentImage[] will capture an image from the webcam. It is even possible to create a live video in the notebook using
...
3
votes
2answers
803 views
Importing .txt or .csv financial data
I am trying to import some financial data exported from Excel. You can find the relevant file here : Text File or CSV File
This is what the data looks like in Excel :
Using the following code to ...
10
votes
1answer
661 views
Web Browsing Automation with Mathematica
I want to build a bot to automate web browsing, this mean something like:
filling forms
press "submit" buttons
find certain text inside pages
and so on...
How can I do this with Mathematica?
The ...
18
votes
5answers
2k views
How do you convert a string containing a number in C scientific notation to a Mathematica number?
Suppose I have a string containing the C-representation of a floating point number, for example
s = "1.23e-5"
and I want to convert this to a Mathematica number. ...
40
votes
3answers
2k views
Recovering data points from an image
Unfortunately, some data can only be obtained in picture form (Japanese publications anyone?). Since this cannot be worked with, it has to be converted to a dataset that can; I was wondering whether ...
1
vote
1answer
317 views
How can I speed up image importing? [closed]
The following examples show how slow it is to load a simple GIF. Can anything be done to make it faster?
System #1: Mathematica 8.0.1.0, HP notebook, Win7 64Bit, 2 x 2.4Ghz Intel Core i5, 2GB RAM, w/ ...
14
votes
2answers
300 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
346 views
How to develop an Import/Export converter for Compress[]ed data?
Mathematica has a cross platform data exchange format, WDX. Unfortunately importing or exporting large data from/to WDX is very slow. Using MX files is very fast, but they are not compatible across ...
6
votes
3answers
318 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 ...
9
votes
1answer
341 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
...
4
votes
3answers
244 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 ...
9
votes
3answers
484 views
Is it possible to import dates and times directly as AbsoluteTime and by pass DateLists?
Date and time calculations are quite slow so I am exploring ways to minimize the number of calculations performed. As an example:
...
6
votes
1answer
213 views
Operations on online files via public URL access
I need M. to access an online public directory via some URL (fake in this case)
http://example.com/images
and perform operations similar to those M. can do on OS directories and files. Examples:
...
15
votes
1answer
414 views
How to export and import Graphs with additional data?
I'm trying to export and then later import graphs with additional data added such as VertexLabels and EdgeLabels. When I export ...
19
votes
3answers
737 views
Importing videos in Mathematica
Mathematica's Import command is purportedly able to import .AVI files. However, I find that many files that I want to import do only result in MMA showing a blank ...
