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18
votes
4answers
1k views

How to integrate functions of linearly interpolated data?

At first, consider integration of pure InterpolatingFunction. Importing some data (works in v.9, for earlier versions one can use this link to download zipped ...
5
votes
2answers
492 views

ListContourPlot interpolation screws up on concave set of data

I want to create ListContourPlots for sets of Data (from a physics simulation) given as Triplets {x, y, f(x, y)}. Certain parameter regions in the x-y-plane are ...
11
votes
2answers
1k views

How do you deal with very large datasets in Mathematica?

This question is in two related parts. The first is about dataset size, the second data wrangling. Part 1: I've built a naive Bayesian classifier on Mathematica. It uses ...
5
votes
2answers
760 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. ...
20
votes
5answers
3k views

How to perform a multi-peak fitting?

I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...
10
votes
2answers
835 views

Finding fourier transform of data and hence frequencies

I looked at all the other questions related to mine before posting this, and they didn't solve my problem. I have a large data set which can be downloaded from here. I'm using the following code to ...
7
votes
3answers
465 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 ...
6
votes
3answers
251 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 ...
3
votes
2answers
206 views

Selecting for 2D points that are within a threshold distance of an upper- and lower-bound number of points

I have a very large set of 2D points: numberOf2DPoints = 10^6; pointList = RandomReal[{0, 1000}, {numberOf2DPoints, 2}]; I'd like to find a way to quickly ...
2
votes
2answers
116 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
37 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: ...
27
votes
4answers
917 views

Filtering beat-to-beat heart rate data

From an experiment, I have a dataset of beat-to-beat heart rate data: a list of the time between each heart beat in [ms]. The data is measured using an infrared optic sensor at the finger tip. The ...
19
votes
3answers
775 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 ...
10
votes
5answers
398 views

Relational joining of tables

A common thing to want to do with data is to combine it (at least I thought this was a common thing). In SQL there is the idea of table joins "select id,v1,v2 from A,B where A.id=B.id" kind of thing. ...
9
votes
1answer
637 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 { ...
6
votes
1answer
147 views

Assign the contents of a “Copy” operation programmatically to a variable?

While an earlier question Cut and paste data from a spreadsheet nominally addresses the issue, a year has past since its OP asked it and I hope that others have come across simpler or more direct ...
11
votes
3answers
436 views

WaveletScalogram in polar coordinates

For given dataset data = Re[Zeta[1/2 + I Range[0, 100, 0.01]]]; It is nice that Mathematica can plot data in both Cartesian and Polar coordinates. ...
3
votes
1answer
112 views

How can I export definitions of several symbols to a single file?

the problem related to this question What I want to do is to Export definition of several symbol into a single file. The reason I choose ...
6
votes
1answer
254 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 ...
6
votes
1answer
290 views

Having trouble fitting data using NonlinearModelFit

I'm trying to fit data = {{2002, 45000}, {2004, 90000}, {2005, 120000}, {2013, 211000}}; to an exponential function ...
5
votes
3answers
241 views

Storing data in the Notebook in readable form

The common problem in my theretical work is a need to import some experimental data to work with. This means that my notebook depends on some external files which makes it difficult to share it with ...
4
votes
3answers
238 views

Determing two Nonlinear model fits with 95% confidence bands from one data set

I have the following data which is postulated to have contributions from two different sources .....as can be seen from the confidence band, many points are out of the band. Question: How can I ...
1
vote
1answer
166 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: ...
4
votes
2answers
261 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 ...
4
votes
1answer
196 views

FindFit not giving a good fit despite good initial parameters

I'm having a problem with FindFit not giving a good fit to my data, even though the initial parameters I give look really good when plotted. The fitting function is ...
4
votes
1answer
2k views

Transform 3D data into 2D color map like Matlab's surf/imagesc

I have a bunch of 3D data (x, y coordinates and values) which is generated in Matlab and I need to render them in a 2D color map with certain axis ranges. Here are the Matlab code and the generated ...
3
votes
1answer
121 views

I need a technique for determining and drawing a line where the density in a listplot jumps up suddenly

Basically I have a two dimensional list plot with a bunch of points between the square of (0,0) and (1,1). The y-values of these points are drawn from a uniform probability distribution between 0 and ...
2
votes
1answer
127 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. ...
2
votes
4answers
494 views

More elegant way

I read ReplaceOrRemoveInvalidOrMissingData Mathematica documentation, and I tried to apply the same approach to my dataset. I've got two problems, but one is only a style problem! There is one more ...
2
votes
1answer
109 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: ...
2
votes
0answers
96 views

Significant platform-dependent efficiency when importing data?

I'm curious, as I understand that answer this way: If you are using a Linux derivative or something like cygwin on Windows, then this is an efficient solution for reading only the third field ...
2
votes
2answers
438 views

How can I control the number format of exported data?

I'm having issues while exporting a tables of numerical values to "*.dat" data files. Here's the thing, sometimes when I export a table, I get more decimals on some random values. The problem is that ...
2
votes
1answer
445 views

Importing data sets from plain-text files and performing operations on them

I am working with a lot of daily weather files in the txt format. I need to calculate a daily quantity from each of them, e.g., daily light intensity, which ...
0
votes
1answer
140 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
139 views

Extracting values

I have imported a data from an excel sheet. I want to extract parts of the list based on some conditions. First I want to create one list whit the The Coca-Cola ...