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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15
votes
1answer
507 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
205 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
169 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
35 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
295 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
300 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
354 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
272 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
123 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
283 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
98 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
80 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
121 views

How to find a fit for a function?

I have the following function: ...
8
votes
3answers
406 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
257 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
983 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
101 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
163 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
315 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
163 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
163 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
332 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
216 views

Looking for ideas for handling a complicated fitting problem

I have the following data: ...
2
votes
2answers
167 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
245 views

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

Given this list of cities: ...
1
vote
1answer
88 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
234 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
127 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
667 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
971 views

Parametric Interpolation of 2D data

I want to create an interpolation through the following 2dim data points: ...
2
votes
2answers
497 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
426 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
550 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
305 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 ...
0
votes
1answer
159 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
73 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 ...
11
votes
3answers
1k views

Smoothing ListContourPlot contours

I have some data of type {{x1, y1, f1}, {x2, y2, f2}, ...} and want to do ListContourPlot. However, there is a problem that the ...
0
votes
1answer
240 views

How to prepare (copy/paste) data from Matlab?

What is the best way to get data from Matlab to Mathematica? For a new project I want to copy/paste a table (or part of it) of datas from Matlab to Mathematica. Copyed from Matlab it is: ...
0
votes
1answer
141 views

Bar Chart: How to adjust the font size for the bar labels as the chart size is manipulated

I have data that represents the binding energy of oxygen on different surfaces. Each bar is a different transition metal, and the length of the bar is the binding energy of oxygen. How do I make the ...
1
vote
1answer
187 views

show fit information on plot

After performing a fit in Mathematica, I would like to show the fitted parameters in a box on the plot showing the fitted function. How would I go about achieving that? Here is a MWE: ...
6
votes
3answers
703 views

Calculate mean of values in bins

Problem description: I have a list of $\{x,y\}$ pairs. I'd like to divide $x$ into equal[*] bins, say $bx_1, bx_2, \ldots$, calculate $\left<y\right>$ for every bin and then plot the bin values ...
19
votes
3answers
989 views

How to extract the edge from a set of points

I have an accumulation of points representing a body as you can see in the image below. From this data I want to generate a list of points or a curve, which is the envelope. The first idea was a ...
2
votes
1answer
104 views

nonlinearnodelfit with a matrix as weights

I have to fit a non linear model to my data and I am trying to use nonlinearmodelfit. The problem is that I have systematic errors, so the ...
3
votes
2answers
370 views

Map of Swedish regions?

There have been some questions dealing with how to draw individual US states since such data doesn't come with Mathematica through its CountryData which offers ...