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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3
votes
2answers
1k 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 ...
3
votes
4answers
691 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
2answers
253 views

Equivalent of Matlab's uigetfile in Mathematica

I was wondering if there an equivalent of the "uigetfile" Matlab function to use it in Mathematica. To be more precise, I want to read many Excel files and I don't want to type a static path; ...
3
votes
2answers
644 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
3answers
400 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
3answers
454 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
2answers
437 views

Why does a certain CSV file import properly into LibreOffice but not into Mathematica 10.0?

I'm working on a project involving data manipulation and it involves working with CSV files. I know that the files are properly formatted as when I import them into LibreOffice, all of the columns ...
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
224 views

Import multiple files from folder in order of date added

I have a folder that contains certain files I want to import. In my case those are .png files. As all the files I want to import contain the phrase "accum" in their filenames, I can use ...
3
votes
3answers
2k 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
2answers
150 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
108 views

Importing multiple tables within a single file

Suppose I have a file with multiple tables, each separated by a line beak, like this: ...
3
votes
2answers
201 views

Import[] exception possibly caused by ToString[] behaviour which I cannot explain

Let me just start by pointing out I'm a new StackExchange user as well as a new Mathematica user (started today!) I mention this as a context to my ineptitude :) I am attempting to read through a ...
3
votes
1answer
147 views

How to sample n frames from a movie file?

I'm looking to import 100 image frames from an mp4 video file at roughly evenly spaced intervals. As $ImportFormats shows, Mathematica can handle Movie files: .avi, .mov, .qt, .flv Multiframe ...
3
votes
2answers
77 views

Manipulation of .csv imported data — no blanks in either of two lists

Above is a .csv file. I am trying to construct two lists of male and female math test scores such that only districts which include info for both male and female students are included i.e. neither ...
3
votes
1answer
346 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
2answers
407 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 ...
3
votes
1answer
322 views

Exporting lists to files

I am trying to write a program which will generate a list of objects and then exports it in a separate file and clears its memory. As an example I tried the following ...
3
votes
1answer
43 views

Why doesn't Import work with XOWA offline Wikipedia database?

I'm having trouble with importing HTML from XOWA offline wikipedia database. I set up a local server for datamining, but I can't access it with Mathematica. I can request a HTML page with ...
3
votes
2answers
240 views

Mathematica data structures for analysis [closed]

I'm starting to learn Mathematica and one thing that has been bugging me is the apparent lack of a good structure for keeping data and metadata for analysis. Something along R's ...
3
votes
1answer
250 views

Easiest way to parse semi-structured text file

I have a plain text file with some data. I need two things: Be able to extract certain values for the various field, e.g. to extract the 'Mean Dose [%]', that is to extract number ...
3
votes
2answers
189 views

Lookup in Inverse Symbolic Calculator+ from Mathematica

There is a useful feature in WolframAlpha that allows to find a possible closed form for approximate numeric values. It can be used, for example, to guess the value of an integral that Mathematica ...
3
votes
1answer
294 views

Plotting with ColorFunction -> GrayLevel - no black

This is probably a fairly trivial question, yet I have been unable to find an answer - help would be much appreciated! :) I am trying to plot a 28 x 28 matrix (tabulated data given here), containing ...
3
votes
1answer
825 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
2answers
86 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 ...
3
votes
1answer
167 views

Using the variable in the MATLAB workspace using MATLink or any other packages

I have a program in MATLAB and after I run the program, I get some results in MATLAB's workspace. Now, I need to use these results in Mathematica. What I currently do is that I save the workspace as a ...
3
votes
1answer
230 views

Importing numerical values from a PDF file

I need the numerical values from pdf files like this one. When I use the usual Import command, the PDF imports, but pages of images. How can Mathematica be used ...
3
votes
2answers
144 views

how to convert string output into executable commands

temp = (layer = #; layerS = ToString[#]; StringForm["Import[\"drainCdg_gdat0``\",\"Table\"]", layerS]) & /@ {1, 2, 3} how to get the output of ...
3
votes
1answer
616 views

Read and filter a text file without importing

I have a large text file of a million sections. Each section contains A lines of header and B lines of numeric data. I want to read the first and last line of B from each section (to have a list of 2 ...
3
votes
2answers
261 views

Since installing mathematica 9 I can't import certain tiffs

I have a notebook written in Mathematica 8 in which I imported Tiff images and everything worked fine. Since I installed Mathematica 9, I get the error: ...
3
votes
1answer
256 views

Efficiently importing XPM matrix data into Mathematica

The XPM file format is an image file format. Although it is primarily intended for icon pixmaps, it can also be used to store matrix data. For example, the GROMACS chemical simulation package uses ...
3
votes
1answer
50 views

How to force Mathematica to interpret a file as HTML?

Some web pages do not explicitly contain the file extension "html" but is formatted that way (like this one). If I saved this page to my computer then Mathematica could parse it correctly. But if I ...
3
votes
1answer
172 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 ...
3
votes
1answer
519 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
145 views

Reading many single files and creating numbered (? or indexed) variable

I tried many different approaches, but I could not solve the following problems, I appreciate your help: What is the best way to read many data files? I mean we have ...
3
votes
1answer
147 views

Reading RData files without RLink

I am using Mathematica 8. I would like to read some RData files which I have received. I do not currently have an installation of R on the machine with Mathematica.
3
votes
1answer
633 views

Mathematica PDF import and fonts

I am trying to put nice LaTeX labels on my Mathematica plots. I can do this manually, or by introducing an extra GNUPlot step into my workflow, but it would streamline the process considerably if ...
3
votes
1answer
75 views

How is Precision of Imported Data managed?

I am working on a financial/banking type application and part of the work is to import numeric data of 15 to 20 digits of precision. I am having trouble determining the best way this should be done. ...
3
votes
1answer
129 views

How to make Import recognize a new file extension? [duplicate]

I've written an import converter for a custom file format, and it all seems to be working as expected, except for the fallback behavior with no arguments: ...
3
votes
2answers
311 views

How to delete all rows in datafile that contain a string

I'm importing some data from a file. However, the file was created by an unreliable instrument, such that the data looks like this: ...
3
votes
2answers
772 views

Importing data into an array, column by column

I'm building a large matrix having different sized rows consisting of a few columns. The different columns are imported .txt files. Why can't I build the matrix column by column? For example, I ...
3
votes
2answers
258 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
1answer
428 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. ...
3
votes
1answer
477 views

Importing file with UCS-2 Little Endian codification

I'm trying to import a text file with UCS-2 Little Endian codification but I can't read it correctly. There's any hidden option to read this files ?? I'd tried with ...
3
votes
3answers
613 views

How can I change the CDF which imports the data and uses it, without execution of code

I am making an application which first imports the data from the Excel file and then uses it in the deployment of a CDF. But is it possible to change the data of the Excel file and see its ...
3
votes
1answer
340 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 ...
3
votes
1answer
213 views

Efficiently reading CSV with ReadList

I have a large CSV file (~1gb) with mixed data. Basically with strings and integers. It takes very long to import this whole dataset with Import[] so I would like ...
3
votes
1answer
260 views

How to make the plot from geotiff format

I have a "GeoTIFF" format map, and I have imported it into Mathematica, then I used the Graphics to plot a point on the map. ...
3
votes
1answer
451 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 ...
3
votes
1answer
557 views

Exporting/Importing a Table of complex numbers

I'm generating a long table of list of the form: PN={{1,2,1+i},{3.5,2.6,2}...},{...},... Using: Export["PN.dat", PN, "Table"] ...