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8
votes
3answers
340 views

Turning a set of random walk data 45 degrees

I have a set of data that is just a "random" (generated by me, not by computer) sequence of length 2000 of 1's and (-1)'s. I used it to plot a 1-D random walk where +1 is step up, (-1) is step down, ...
0
votes
0answers
32 views

How to investigate the seasonality of the data

After asking how to get rid of the seasonality of this set of data, I'd like to close the circle with a last question: How to detect seasonality in data using Mathematica? A generic answer (not ...
3
votes
2answers
72 views

Deseasonalize the data of traffic growth for the past data

In another question (Using TimeSeriesForecast for forecasting the traffic growth) I asked to use the TimeSeriesForecast on this set of data the answer provided the plot with and without the ...
3
votes
2answers
135 views

How can I create a 3D representation of an object with known coordinates and adjacency table in mathematica?

Basically I want to create an object with specified coordinates and adjacency table, like in page two of this article. I'm completely new to using Mathematica, any help would be great! EDIT: So I ...
1
vote
1answer
42 views

Data Table Manipulation in Mathematica 10

I would like to select columns from a table by column name. I tried the solution described here: Data Table Manipulation in Mathematica: Step 2 . I am using Mathematica 10. (I would write a comment ...
3
votes
1answer
44 views

How do I find local minimums in data? [duplicate]

Mathematica easily allows you to use FindPeaks to find local maxima in your data is there any equivalent function for finding local minima?
2
votes
2answers
149 views

Entropy of the elements of a general data set

I have the following data set, and wish to track the evolution of the entropy of each element within the set. I have evaluated the entropy for some elements, but how does one evaluate the entropy of ...
0
votes
0answers
43 views

System stochastic nonlinear differential equation, Ito process?

I'm trying to solve a system of nonlinear stochastic differential equation. It is a discrete nonlinear schrodinger system of n equation, with n independet weiner process. I'm actually using the Ito ...
0
votes
1answer
32 views

Working on a certain column after importing data from a file

I'm trying to import a file with 2 columns, in TSV format. Something like this: ...
1
vote
3answers
98 views

Read data from file starting at a certain point

I have files of data that come with a whole bunch of junk in the beginning before the actual columns of data start. Is there any way to tell Mathematica to start putting the data into a table from ...
0
votes
2answers
36 views

Selecting elements from a list [duplicate]

I have the following array of numbers: a = {{0, 2, 5}, {3, 5, 1}, {4, 0, 5}, {8, 3, 4}, {0, 8, 6}}; then I make a list of the first row with ...
1
vote
2answers
67 views

Entering coordinates of 2D points using the keyboard

I am studying the singular points of a triangle. I need to get the vertices of the triangle and then work with them. I have worked with the function Input, but I ...
0
votes
2answers
50 views

Fitting data in form $f = f_0 + c A^x$

The Fit[] function in Mathematica can fit data in form of $f = f_0+c_1x+c_2x^2+...$ ($f_0$ and $c_i$ are unknown constants), is there a function can fit date in ...
2
votes
3answers
107 views

Plot a table of lists

I want to make a point plot of a table with lists in it. Assume I have data like this: data={{1,2,3,4},{5,6},{1,5},{2,4}}; and now I want to make a point plot ...
1
vote
1answer
63 views

A bug won't let me import JSON files

I have been working on a project and I have been using JSON to build some networks, the code I use is: ...
2
votes
1answer
86 views

Export generated mesh

Say I have generated a mesh using ToElementMesh, following one of the examples here: http://reference.wolfram.com/language/FEMDocumentation/ref/ToElementMesh.html ...
3
votes
0answers
73 views

How to efficiently read data from any part inside huge file

I have a data file (over 2.5 GB) and I want to do calculations on the data. At first I used. data=ReadList["file", Record,n] I still have three problems: 1- ...
1
vote
1answer
90 views
2
votes
3answers
144 views

Plot a bunch of lines in 3D from point data

I have a 12*25 array, wherein each entry is of the form $\{x,y,z\}$. So 12 different $x$ values, 25 different $y$ values and 12*15 $z$ values in all. I'd like to plot 12 curves of various $x$ values ...
0
votes
0answers
22 views

how can sent data to Mathematica and get result in java? [duplicate]

I try to develop an math script calculator in java. My script has advance math functions and I can't calculate them in java.(for example limit, plot, ... ) Is any way for sending script to ...
0
votes
1answer
31 views

Is there a limit for DensityHistogram data amount?

I'm trying Mathematica for first time and while trying to do a Density Histogram with around 300 000 points, I get an error "THE INPUTED DATA is not a valid dataset or list of datasets." Maybe it's ...
6
votes
1answer
120 views

Is Mathematica's (v10.0.2) NetCDF exporter broken?

I'm trying something very simple, namely: Export["file.nc", {"Datasets" -> {"seqs" -> {"AAA", "BBB"}}}, "Rules"] And getting Java errors about "illegal ...
2
votes
1answer
98 views

Finding periodicity of multidimensional data?

I have a data set consisting of measurements of an $n$-dimensional vector $\mathbf{x}(t)$, at $N$ distinct time points $t_i$. The time points $t_i$ are equally spaced. I need to find the dominant ...
2
votes
0answers
75 views

Cloud cover fraction

I need to make use of Mathematica's WeatherData functionality, the CloudCoverFraction property, specifically. However, it does ...
0
votes
0answers
18 views

Binomial Regression where n > 1

I am not well versed in Generalized Linear Models, but am trying to use this approach to model some discrete data. I have binomial data where the sample size for each observation is the same size, ...
0
votes
1answer
52 views

How to fit this data to be used in NIntegrate later?

I have a list of data points that resemble a chi-squared distribution (long tailed gaussian) that I am having trouble fitting or finding an equation with. The goal is to use the fitted equation in an ...
3
votes
3answers
292 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 ...
0
votes
1answer
49 views

How to assign the array data to variables?

A very basic question but puzzled me for long time on how to assign array to variables. For instance, we have array {{t1,x1},{t2,x2}...{tn,xn}} how to assign the first element to variable t and ...
4
votes
1answer
102 views

Most efficient searching algorithm in a table

I am completely new in Mathematica (and in data analysis in general) and I find it really useful, although I still do not use it properly. I have the following question related to data manipulation: ...
6
votes
0answers
142 views

Implementation of Partial Least Squares (PLS)?

I'm looking for a PLS implementation for Wolfram Mathematica. I just cant seem to find any implementation for it - do you know one? In general, I'm a bit confused that there exist only so few ...
1
vote
1answer
60 views

FindClusters memory exception problem in dealing with 1Dimensional data?

data=RandomReal[10,{30000}]; FindClusters[data,2]; Why in this little data set, FindClusters Load so much memory? and ...
1
vote
1answer
57 views

List Manipulation and Removing Cases

I've imported a large data set, manually removing headers in the .rtf file where it originates. However, when I import this data, I receive this output: ...
1
vote
1answer
81 views

FinancialData Input

What does the function FinancialData require as input for natural gas: http://finance.yahoo.com/q?s=NGG15.NYM Is it easier to export the natural gas data to ...
1
vote
2answers
187 views

How to obtain the best possibe NonlinearFit

Here is some sample data ...
6
votes
2answers
150 views

Building bounded polygon around heatmap (or points)

I have a set of data for world marine piracy. I'd like to build polygons encircling areas of active piracy. So to start with I get piracy data and make a heatmap from it. ...
22
votes
1answer
341 views

Visual representation of a Ranking over time (image provided)

[Disclaimer: I initially posted this question on stackOverflow 2 months ago and think it might be better suited for this forum (link to original question)] The graph below shows a ranking of ...
1
vote
1answer
70 views

Mixture coefficients and Parameter estimation for moving Normal distributions

I am searching for a way to do the following steps below. I am stumped and I have stumped a few profs too. Any help would be appreciated. I would like to import data from, say, excel or a .txt file ...
1
vote
1answer
101 views

ReadList can't read “.csv” data with correct line number?

Well, the problem was solved today. Since "testAll.csv" is generated by Java/Eclipse, and I noticed that the LineSeperator is ...
3
votes
3answers
171 views

How to detect outlier in data of an unknown function $f(x)$

Suppose I have an unknown function $f(x)$ that is monotonic, convex and nonlinear by definition. I somehow evaluated it at 1000 nonuniform $x$ points. By ploting these data, I found a very obvious ...
0
votes
1answer
86 views

Fitting data with inclusion of constraints

How do I find a fit for the dataS (see below) with the constraint that the parameter np is an integer, and that the parameters la+lc = 100. A weak attempt at this is provided below for a specific ...
5
votes
1answer
182 views

Forcing NonLinearModelFit through a point

Like the title says, is there a way to make an NLM fit pass through a specific point.
1
vote
1answer
122 views

Country density plot of lines (highways)

I love solution from question (histogram as well as distrubution) http://mathematica.stackexchange.com/questions/31948/show-density-plot-on-us-map#=. But both cases are a bit more difficult in my ...
0
votes
0answers
46 views

How to determine if a point is within a geopositioned RegionMember

I have a KML file which contains an area of interest, I also have a number of lat/long geo positions. I'm trying to filter out the points not within my AOI. So I have my KML file. I convert it to a ...
1
vote
3answers
193 views

How to import files with headers?

R has excellent header supports such as read.table with header options. I don't want to mess up with text-processing or stream-processing. I am looking for a similar tool as in R because it saves a ...
2
votes
1answer
63 views

Statistical Analyzis of Observed Data (Queuing Process)

Basically I have a process that belongs to a certain state at any point of time. However, the time intervals are not fixed (in fact they are exponentially distributed). Essentially, the data points ...
1
vote
1answer
98 views

How to append data in an already existing data .txt file in newline or in tab separtion?

Say I have an already existing .txt file containing data in the following format. $a \qquad b$ Now at different times I will successively have data like ...
2
votes
1answer
78 views

Struggling with FindFit

I'm trying to fit a sinusoidal wave to some numerical data. I can do it by hand using manipulate, so I know roughly the sort of parameter values that I should get back, but functions such as FindFit ...
5
votes
2answers
149 views

Getting the Cumulative Distribution Function of f(x) from a dataset of x

I've a data set $\mathcal{X}$ which consists of randomly generated numbers. Let's say for example data = RandomVariate[ExponentialDistribution[1], 10^4]; My aim ...
1
vote
2answers
75 views

How do you (sanely) fix up data in a csv/table?

I have data in a CSV file I've Import[]ed. Some of the data needs fixing up - date formats changed, data normalized, etc. After fixing up I'll insert it into an SQL database. My CSV file has ...
1
vote
1answer
57 views

Export data from NDSolve when they meet a certain condition

I need to export to a txt file the data from the following system of equations: ...