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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1
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2answers
120 views

How to cut imported audio?

How to cut an audio clip imported by the Import function? E.g. I'm interested in the content starting from the 100th sample up to the 200th. I'd like to avoid ...
1
vote
1answer
112 views

Import graphml file in mathematica

I am trying import a graphml file I created with NodeXL in mathematica in order to create a network. However when i try to import it I get the error message: "Cannot import data as GraphML format". ...
4
votes
2answers
67 views

importing a 150 MB .wav crashes Mathematica

rawdata = Import["rawdata_10min.wav"] crashes Mathematica when the file is 150 MB, but does not crash Mathematica when the file is 20 MB.
2
votes
2answers
560 views

How to Flatten and stack Efficiently 50000 Images

I have 50000 grayscale images with 56*56 pixels each one. I need to flatten images and stakck it in the same array with dimensions 50000*3136 after that export the file as .CSV. I am doing this code ...
0
votes
1answer
76 views

Importing $\LaTeX$

I have a LaTex file, and import it this way: tex=Import["texfile.tex"]; Now according to Help, this returns a notebook expression: ...
3
votes
1answer
31 views

Skipping commented in a stream from OpenRead

Is there a solution to skip comments in text files that are imported with OpenRead? I know there are solutions for Importand ...
1
vote
1answer
62 views

How to interpret and extract the information from the JSON (JavaScript Object Notation)? [closed]

How to interpret and extract the information from the JSON (JavaScript Object Notation)? I would extract the information and plot the information graphically. Please advise and comment. Thank you. ...
0
votes
1answer
43 views

How to analyze a large wav file?

I have a large wav file (100 Mb). Any operation on it is time consuming. For example, to Import it takes about 1-2 minutes. The next step seems to be to figure out how it is encoded, since WAV files ...
0
votes
2answers
80 views

How to make a graph form imported spreadsheet data [closed]

I've three csv files: v.csv for vertex data, like this: 1 2 3 ... e.csv for edges: 1,2 2,4 2,24 3,1 ... and vcoor.csv for vertex coordinates: 23.4, 35.2 23.4, 40.3 ... I know how to construct a ...
2
votes
1answer
80 views

Change bond cutoff distance when plotting .xyz files

When plotting a molecule from a xyz data file, Mathematica automatically adds the bonds between the atoms. But in my case it adds too many bonds, not only between nearest neighbours but also between ...
7
votes
2answers
217 views

Extracting and displaying data from GW150914 hdf5 files

Has anyone looked at the LIGO data using Mathematica or know how to do this? I'm not familiar with the hdf5 format but I've been able to import the data, consisting primarily of 131,072 floating ...
1
vote
1answer
61 views

Cannot import PDF with JPXDecode or JBIG2Decode Filters?

I am trying to what I think should be a very basic thing, which is to import a large PDF from my files into Mathematica. The long term goal is to extract images from the PDF. The original command was ...
1
vote
2answers
528 views

Importing base-64 encoded Canvas element into Mathematica

The aim of this code is to transfer a web image into webMathematica for image manipulation. Since the question here failed to resolve direct URL loading, I tried a different method of extraction ...
5
votes
0answers
68 views

why does ReadString[“fname”,term] open a persistent stream, and how to close it?

Bug introduced in 10.0 and fixed in 10.3.0 Create a file temp.txt with the following content: test1 ;;; test2 ;;; test3 ;;; ...
25
votes
1answer
331 views

Getting Mathematica.SE reputation data

I'm asking the following on behalf of Mr.Wizard. On StackOverflow I used the old v1.0 SO API and Mathematica to obtain user reputation data. Now we are no longer a tag on StackOverflow and the v2.1 ...
0
votes
1answer
48 views

Combining first 5 columns from CSV file into AbsoluteTime date

Thanks in advance for all your help. I need to import data from a CSV file that looks like : (easier to read in excel) I would like to convert the data into timestamps by creating a Table with 2 ...
0
votes
1answer
49 views

Improving performance Importing Table

I am currently working on mathematica script on a Raspberry Pi, which will periodically (10 secs) be launched by a bash script. However the runtime of my script really isn't the best. It's actually ...
4
votes
1answer
81 views

How to get sub property from json result?

I'm brand new to Mathematica and I imported a json: data = ImportString["{\"x\":1,\"y\":1}", "json"] and result: ...
2
votes
0answers
81 views

Using SHP files to draw a density map [closed]

My SHP file of census block groups has polygons and associated employment data for each block group. Is there a simple way to draw an employment density map? I've played around with ...
11
votes
3answers
1k 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: ...
11
votes
2answers
1k views

Stream CSV or TSV files

RAM limitations make import impractical for large CSV files. Is it possible to Stream CSV correctly? str = OpenRead["EU.csv"]; Read[str, "CSV"] Read::readn: ...
3
votes
2answers
104 views

How do I run 1-855 data points( imported from excel sheet) into a formula to obtain value for each data point?

I am very new to Mathematica and I just couldn't figure out the solution for the following problem. I have two columns in an Excel file. I have imported the 1st column as ...
10
votes
1answer
119 views

Converting text from unsupported encodings like 866 into known by Mathematica?

The list of character encodings currently supported by Mathematica is still extremely limited. For example, it supports only three standard IBM PC (OEM) code pages: ...
1
vote
1answer
78 views

How to get missing lines from a file? [closed]

Let's say I have this file dat.csv which basically is a number of strings like that: animal horse duck dog plant tree grass sunflower sky oxygen nytrogen air ...
6
votes
0answers
71 views
0
votes
2answers
55 views

Assigning columns of data from a file to variables extracted from headers

I'm very new to Mathematica. I want import a file in which the first colum is a function f1, the second another function f2. So the file looks like this: ...
3
votes
3answers
323 views

URLFetch functionality for a Persian website

I want to fetch the content of a Persian website. I tried URLFetch["http://www.tsetmc.com/"] Why is Mathematica unable to recode the characters in the results ...
1
vote
1answer
82 views

Export the coordinates of STL object

Hi I currently have a STL file of a 3D object Is it possible for me to obtain the coordinates of the object so that I can just input that into Autodesk Inventor
1
vote
0answers
37 views

Order of importing data from files

I have many text files numbered from 1 to 1 million in numerical order. Within each text file is 5 columns of data (TAB spaced) with many rows. I effectively want to take the minimum value from each ...
0
votes
1answer
74 views

How to convert this .txt data into a list of points [closed]

Question How to import data from a .txt file into Mathematica and convert it to an expression? Download the .txt file here (click download): http://pastebin.com/2NW2DfiE
0
votes
1answer
74 views

Why vertices number increased when importing .STL file

I import a .STL Import[*.st,"VertexData"] file on mathematica and I remark that the number of vertices is increased comparing to the number given by Blender. ...
9
votes
3answers
444 views

Why doesn't DumpSave work for elements created within a local notebook context?

I recently noticed that when dealing with notebooks with local context, I cannot successfully DumpSave variables, or, rather, when I call ...
3
votes
2answers
919 views

video image recognition [closed]

Has anybody experience with video and image recognition? I've made a video of two teams playing soccer. Now I would like to translate each soccer-player to a (x,y) coordinate and follow them during ...
3
votes
1answer
67 views

Reading an exported List

I have exported a list of 2d coordinates as a List: Export["F:\\coordinates.dat", coordinates, "List"]; You can access the ...
1
vote
0answers
42 views

What is a good way to import interpolating functions of large size? [duplicate]

I was generating a set of eigenfunctions from a differential equation using NDEigensystem. Because of the computer time cost is too high, I thought it'd be better ...
0
votes
1answer
75 views

Applying a formula to the data in several files [duplicate]

I am calculating with the depth data recorded in a number of files with extension .log. The depth data is like this and I loaded it by means of Mathematica: ...
2
votes
1answer
48 views

read Python-generated data file

I've read similar-but-not-quite-the-same questions : I have to read a python-generated data file which contains complex numbers. So, the numbers appear as (real+imag j). And of course Mathematica ...
2
votes
1answer
165 views

Import 'file not found' error. Why? [closed]

I'm trying to import a file, and for that I'm using the following code: ...
1
vote
1answer
46 views

Trying to get simple excel data to be imported as a social network directed graph

My data has two columns that we'll call A and B. The columns proceed as such A B A1 B1 A2 B2 A3 B3 .... I'm trying to make this into a directed graph where A1 has an outgoing edge to B1 and ...
2
votes
2answers
256 views

Follow each pixel brightness in set of images (Memory constrained)

I have a set of 2700 consecutive png images (8bit, 2048*2048 pixels). I would like to visualize the intensity variation of each pixel vs. image number. Here is an example of 10 images: ...
-1
votes
4answers
163 views

Import vs ReadList CSV file with Currency Values

A testing file with the specified format can be downloaded from here Let's read a few lines from this file ...
3
votes
2answers
152 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 ...
5
votes
2answers
262 views

Max of imported numerical data will not work

I loaded a list with 400,000 values from a file. The list was loaded correctly as I can get it's length (by Length[]) and I can also plot it. Why can't I get the Max or Min of this list though? When ...
0
votes
1answer
77 views

SocialMediaData[“Twitter”] - strange output

I am getting error messages when I use SocialMediaData["Twitter"]: ...
5
votes
1answer
100 views

ReadList ignore comment lines?

Is there a way to make ReadList ignore certain "comment lines" (say, all lines that start with #, or in general all lines that ...
6
votes
1answer
409 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 ...
2
votes
2answers
76 views

How to separate the double columns while reading file

I have a file which has contents of the form 10533 "MENDOZAT " 115.0000 : 1 1.00000 Now I want to separate the words and get it as a list. like ...
4
votes
2answers
218 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 ...
3
votes
0answers
87 views

WDF specification?

Motivated by a recent question on the meaning of all sorts of W* acronyms, I would like to get more information about the Wolfram Data Framework (WDF). On its web page ...