Questions on systematic data handling and analysis, including data correction, manipulation, or selection of user-data or built-in data available with Mathematica.

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1
vote
1answer
148 views

ReadList or any other command to read in blocks of very large numbers

I have a data file, data.txt, having following data: ...
0
votes
1answer
52 views

Automatically restoring the state of a prior session [duplicate]

I have the following problem (I guess a very naive one): I work with some data and make a statistical analysis in Mathematica. I do it over several days and each time I open the file, I have to go ...
3
votes
1answer
96 views

Calculating groupwise mean in Mathematica

I have a huge panel data with more than 2.5 million observations and more than 15000 groups. I want to calculate group-wise mean and I also need Id variable in my result. This is what I have done. ...
4
votes
1answer
224 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 ...
5
votes
3answers
427 views

Creating Correlation Table (and Working) With Missing Data

I am working with data that contains missing values (I have several variables (across the columns) and several observations (across the rows) in an excel spreadsheet). Example of the data structure: ...
5
votes
1answer
154 views

Tools for Importing/working with SEED seismographic data in Mathematica?

Do you know if exist a library or a package in order to import and work with SEED Seismographic data in Mathematica?
11
votes
2answers
493 views

Map of United States as a 3D histogram

By combining the state data from here and the extrusion code from here I have managed to make prisms of the various US states such as However, the extrusion method looses information about the ...
3
votes
1answer
221 views

Spectral Clustering

I am attempting to implement a spectral clustering routine using Mathematica, but I am encountering difficulties. Using the standard Gaussian similarity function found in section 2.2 of this paper ...
15
votes
1answer
537 views

Export dataset to JSON

I'm experiencing a weird issue. Consider a dataset defined like this: dataset = Dataset[{<|"a" -> 1, "b" -> 2|>, <|"a" -> 3, "b" -> 4|>}]; ...
9
votes
1answer
212 views

Median of Dataset in Mathematica 10

I'm having trouble calculating the median of a Dataset[] in Mathematica 10. The situation is as follows. Consider a dataset that was defined as follows: ...
3
votes
1answer
173 views

Extract data from WeatherData as a list of associations

Given weather data for 2013 and 2014 as follows: ...
6
votes
1answer
91 views

How to provide data to users in a way similar to Mathematica's curated data

How can one go about implementing a custom data backend usable by Mathematica? For example something like CountryData or ...
1
vote
0answers
36 views

Updating values in a Dataset [duplicate]

I'm starting to work with datasets. They seem like a useful addition to Mathematica. However, there's one fairly major stumbling block I can't get over. How do I update data in a dataset? I have a ...
4
votes
1answer
303 views

How to clean up messy data

The start of my question is about one specific situation - I have some erroneous lat/long values in a dataset which I need to clean up. But I'd like it to cover the overall topic of cleaning up messy ...
8
votes
3answers
307 views

“NotAvailable” and “NotApplicable” data points returned by WeatherData[]

I am trying to use ListVectorPlot in combination with WeatherData and CountryData to show ...
2
votes
1answer
110 views

Setting a Row from a Matrix as Variable

I'm not advanced in Mathematica but I'm trying to get better. I have a big set of Data and I want to Plot the first row against ...
1
vote
1answer
389 views

Convolving data set with gaussian profile

I have a spectrum looking like List, and I want to convole it with a gaussian of the form PDF[NormalDistribution[μ, σ], x] (where σ also depends on x). The raw ...
5
votes
1answer
287 views

How to create a real-time dashboard in Mathematica?

I am trying to figure out how to use Mathematica as a real-time interface. I've used Excel/ODBC connection to a SQL database to use the graphing functions within to get my real-time dashboard. I ...
1
vote
1answer
134 views

Distance between data and curve

I have two datasets: ...
2
votes
2answers
127 views

Obtain data points from a density plot

I have a density plot, for example DensityPlot[Sin[x*y],{x,0,2pi},{y,0,2pi}]. Then I would like to collect points from this densityplot into a file so that I ...
3
votes
1answer
300 views

BarChart that lines up with dates in DateListPlot

I am trying to create a chart similar to the view offered by TradingChart, but with custom data not relating to finance. ...
0
votes
1answer
108 views

Problem of how to manipulate Taylor/McLaurin series

I'm new to Mathematica so I don't know very well the program itself. I would like to manipulate as he does this person in youtube: http://www.youtube.com/watch?v=fCJHvQaGNiQ But I put all the ...
1
vote
0answers
99 views

Datastream to Mathematica

I currently use data from Thomson Reuters Datastream. With an add-in in Excel, the data can be requested. Because I need to use the data in Mathematica, and I need to update the data frequently: Is it ...
1
vote
0answers
86 views

Historical Prices via FinancialData

I downloaded the historical stock prices for some stocks in the period 1990-2013 via FinancialData some months ago and computed the financial returns. Now I downloaded the data again for the same ...
0
votes
1answer
123 views

How to find a fit for a function?

I have the following function: ...
8
votes
3answers
419 views

How to parse information contained in a file name

I have a set of files containing my data, and the file-names contain relevant information that I would like to extract. What I have is: ...
3
votes
2answers
263 views

Dealing with a huge dataset

I have two ingredients here: a big dataset contained in a list, with ~ 20M values. a function that takes as each element of the list as input and yields True or False I want to save somewhere the ...
0
votes
1answer
1k views

How to plot data with error bars on a log scale in Mathematica 9?

I have data in the form d={{x1,y1,dy1},{x2,y2,dy2},..{xn,yn,dyn}}; so the error bars are different for each coordinate pair. I want to plot on a logarithmic ...
2
votes
2answers
102 views

Importing Data and Devoting Their Names to Them

There are some files in a directory. I have used of SetDiroctory to access all of them. SetDirectory["C:\\Users\\SE7EN\\Desktop\\mathematica\\test"]; I can visit ...
1
vote
2answers
165 views

dropping a row with at least one value larger than a particular value

So for instance I have M X N table. I want to drop any row which has an element larger than, say, one in the second or the third column. I guess I have to do some sort of pattern matching. But not ...
1
vote
1answer
332 views

Find polynomial equation for set of 3D data

data was given in columns in the order {y, x, z}, with y dependent on x, z ...
2
votes
2answers
164 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 ...
0
votes
1answer
164 views

How to load data into a Manipulate expression

I have data showing truncated octahedron geometry changing with time. How can I read those data into a Manipulate expression? To be specific, I want to manipulate ...
1
vote
4answers
338 views

random split a dataset

I've got a very simple problem, but not so trivial. I need to split a dataset (input and output data) in three part randomly: training set 70%, validation set 20% and is test set 10%. First of all ...
6
votes
3answers
220 views

Looking for ideas for handling a complicated fitting problem

I have the following data: ...
2
votes
2answers
172 views

Building adjacency matrix from set data

I have two sets: games and players. Players pick their games. As such I will have data say g1={p1,p3,p5},g2={p2,p4},g3={p2,p3,p5}. My interest though is to build the connections among players because ...
2
votes
1answer
256 views

Using a web-crawler to search website for occurrences of keywords

Given this list of cities: ...
1
vote
1answer
89 views

How to create a column for ordering values

I have a dataset, where some data has to be ranked in regard to the number of ranking of the total dataset. I've made a simple example below: ...
1
vote
2answers
247 views

From a list of (x,y) pairs, generate a new list of (x,ymean) pairs, where ymean is the average of all y's with the same x in the original list [duplicate]

This seems like the sort of thing where Mathematica can give a very simple solution. I have a list of points {x,y}: ...
0
votes
1answer
132 views

Importing a text file into a matrix format

I am attempting to perform a comparison of pseudorandom number generation with the RAND Corporation's "A Million Random Digits with 100,000 Normal Deviates" for a Computational Physics course. I have ...
4
votes
2answers
692 views

What is the Mathematica way of joining two tables?

Is there a special Mathematica way of joining tables of data together, so that I would get similar functionality as if I was running a database with sql? For example, I have one particular table ...
0
votes
1answer
40 views

save all inputs as list [duplicate]

I received three results of calculations: {k->0.190729} {k->0.197575} {k->0.249319} Could you help me write the results in the following form: ...
15
votes
3answers
1k views

Parametric Interpolation of 2D data

I want to create an interpolation through the following 2dim data points: ...
2
votes
2answers
511 views

List density plot for non-uniform data

I am trying to make a density plot to show the data that can found here. I tried with GNUplot previously. The result of GNUplot density plot for a rectangular set of data. I am able to do this only ...
5
votes
4answers
434 views

Breaking a sorted list into bins of a specified size

Can somebody please explain me the following: If I try to split data every increase in 0.5: ...
2
votes
1answer
565 views

Data filtering using Butterworth filter

I want to filter data using Butterworth filter. I am currently using Matlab and I want to know how to do it in Mathematica. I have the following data: ...
2
votes
1answer
318 views

Importing data from excel and assigning a variable to each of its columns

How should I assign variables to the data imported from excel containing 3 columns which are time, mean and standard deviation. I want to perform operations on the three variables to get new ...
1
vote
1answer
167 views

How to efficiently distinguish the rewired edges in WattsStrogatzGraphDistribution?

The WattsStrogatzGraphDistribution function is a way to construct random graphs based on Watts and Strogatz small world model. The ...
0
votes
0answers
76 views

How to save all data in all variables in context different than “global”?

I have seen questions on saving data on "global" context. Now if I set my notebook's evaluation context "unique to this notebook". the global context doesn't work quite well. Any idea what should i do ...
0
votes
0answers
98 views

Discrete Fourier Transform and data manipulate

I solve a system od ODE and i save the discrete solution (i.e.: x,y,vx,vy, or a subset of it) in a file. Then i try to call the DFT on this file but the problem is that i must have also the time in ...