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14
votes
1answer
182 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|>}]; ...
0
votes
1answer
15 views

Right data format when EmpiricalDistribution expects “Rectangular Array”

I have the following code to generate random data (these are the eigenvalues of a non-central Wishart matrix, and I am interested in their distribution). m = 2; n = 3; nonce = {{1, 0}, {0, 0}, {0, ...
13
votes
2answers
711 views

Dealing with large files

I have a *.dat file in which the contents are basically one giant list: {1,2,3,4} {5,6,7,8} {9,10,11,12} and so on. I'd like to read in the first 500 members { ...
13
votes
4answers
931 views

How to change element color in Periodic Table?

The command ColorData["Atoms", "Panel"] generates a periodic table. As I don't want to reinvent the wheel, I asked myself how to change the color of each cell ...
15
votes
4answers
911 views

Plotting data points: Optimizing size and visuals

The following problem is one that may have showed up to you while plotting a large data collection. Suppose you have a data set of say 1 million points. ...
5
votes
2answers
74 views

Exporting row vector as a column in excel

I want to export a vector in Mathematica to appear as a column in Excel. I am trying A={1, 2, 3}; Export["mfile.xls", {"A" -> A}] But it is showing 1,2,3 in ...
2
votes
1answer
49 views

Import selective elements from mixed (text and numbers) data file

How can I import only the 2nd and 5th elements (numbers, located in the 2nd and 5th columns) from all n raws of a data file (.xlxx) that contains both numbers and text. Imported data be inserted into ...
1
vote
1answer
47 views
0
votes
1answer
37 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
84 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. ...
3
votes
1answer
80 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 ...
11
votes
2answers
273 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 ...
5
votes
3answers
128 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: ...
4
votes
1answer
55 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
1answer
391 views

Map of Specific US States? (Isolated)

My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to ...
1
vote
1answer
82 views

How to get matching starting dates for different `FinancialData` properties? [closed]

Why do the "Return" and "Volume" outputs of FinancialData differ? Consider the following ...
0
votes
0answers
94 views

Spectral Clustering

I am interested in the following question: How is it possible to check whether an algorithm is working properly? However, this question is too general for the post and I'd like to restrict attention ...
5
votes
2answers
811 views

How to extract data from contour plot as a text file?

I have the following expression from which I want to extract data for a contour plot. ...
1
vote
1answer
125 views
2
votes
1answer
93 views

Extract data from WeatherData as a list of associations

Given weather data for 2013 and 2014 as follows: ...
7
votes
0answers
124 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: ...
5
votes
1answer
69 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
25 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
199 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 ...
1
vote
1answer
93 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 ...
4
votes
2answers
549 views

Check Google PageRank for a given URL

Does anyone know how to write a Mathematica function that returns the Google PageRank of a given URL? I found a tutorial for achieving this in a bash script here, but I have no idea how to port this ...
6
votes
3answers
198 views

A Case of DeleteCases for WeatherData

I am trying to use ListVectorPlot in combination with WeatherData and CountryData to show ...
1
vote
1answer
83 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 ...
3
votes
1answer
152 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 ...
2
votes
2answers
78 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 ...
2
votes
1answer
136 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
78 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
72 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 ...
2
votes
2answers
797 views

Find a best fitting curve for some data with no regular pattern

Suppose some data with no regular pattern is given, so common patterns of functions all fail to fit it. Then how can one find the best fitting curve? I believe there will be some data for which we can ...
1
vote
2answers
83 views

Missing something in my input for CountryData dependencies

I'm trying to find (a)which countries have dependencies (b)and a list of countries that consider themselves dependencies (c)and a list of countries that don't consider themselves dependencies. ...
1
vote
0answers
47 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 ...
5
votes
3answers
178 views
11
votes
2answers
510 views

Graph databases / Nosql with Mathematica

I am very new to mathematica but it looks like an interesting language and I would like to explore it for a future project to create a web search engine. It seems like it would be fairly well suited ...
0
votes
1answer
86 views

How to find a fit for a function?

I have the following function: ...
6
votes
3answers
266 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
225 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 ...
1
vote
2answers
121 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 ...
0
votes
0answers
45 views

Creating ODBC connection on mac

Iam not able to create a ODBC connection on mac through mathematica even though i have created a connection successfully through ODBC Administrator. The error message iam getting was: JDBC::error: ...
2
votes
2answers
92 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 ...
0
votes
1answer
273 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 ...
0
votes
1answer
151 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 ...
2
votes
2answers
120 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
87 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 ...
1
vote
4answers
187 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 ...
2
votes
1answer
168 views