Questions on the use of mathematical techniques to extract properties from given data. Consider if your question might be more suited for Cross Validated (stats.SE) instead.

learn more… | top users | synonyms

0
votes
0answers
3 views

Categorical Survey Heterogeneity Measure?

A survey asks the user to assign ten stick figures into four categories: strongly oppose, weakly oppose, weakly support, strongly support. The survey has been completed, so it is too late to redesign ...
2
votes
2answers
21 views

Power set of a set containing a set

I need some help understanding this concept a little better. I understand the general power sets, but only worked nice and easy examples where only the set consisted of only single elements like ...
0
votes
0answers
9 views

What is the proper name of a model that takes as input the output of another model?

Thanks in advance for the help. I am writing a paper and for the life of me can't remember the proper term for a model that works as follows. rawData -> model1 -> outputModel1 -> model2 -> ...
2
votes
0answers
16 views

Which significance test can be used in this instance? - paired, non-normal means [on hold]

I'm currently writing my final year dissertation for a Biology degree, and I am really struggling with the stats behind my results. I have a data set of behaviours for a herd of captive elephants ...
1
vote
0answers
25 views

Are there any programs like family echo that I can use to map mathematics?

Family echo is an online program that allows one to make a family tree, if nothing is clicked it shows most of the family tree as it is, but if one clicks a name one can see clearly all the ancestors ...
0
votes
0answers
34 views

Mathematically compare two sets of oscillatory data

I need to compare two sets of oscillatory data from a biological process. The data is quite noisy. Both sets have a similar frequency spectrum. I wonder what is the appropriate mathematical tool to ...
0
votes
1answer
30 views

There are 2 red, 3 pink, 4 orange, and 5 yellow jelly beans in the pocket. how many different ways can you choose at least one jelly bean?

Thanks a lot!There are 2 red, 3 pink, 4 orange, and 5 yellow jelly beans in the pocket. how many different ways can you choose at least one jelly bean?
0
votes
0answers
35 views

Combine two data sets, possibly Bayesian Updating? [on hold]

I am a PhD student and I am currently looking at railway track degradation. I have two sets of data, recent and older. The older data set is about twice the size (at about 3400 data entries) but has ...
-4
votes
2answers
65 views

What property of $n$ is being calculated here? [closed]

I have the following data: $$\begin{matrix} n & f(n)\\ 1 & 1 \\ 2 & 1\\ 6 & 2\\ 8 & 4\\ 3 & 2\\ 15& 8\\ 9 & 6\\ 11&10\\ 4 & 2\\ \end {matrix}$$ My question ...
0
votes
2answers
54 views

What property of $n$ does this test?

I have the following sample data: 1 true 3 false 12 false 10 true 7 true 9 false 8 false My question is, what property of ...
0
votes
0answers
14 views

How to normalize scoring to eliminate bias?

Background: I'm writing an app to allow multiple people to rate an object on a scale of 1-10. There are a few hundred objects to be rated, so I'd like to allow the reviewers to review what they can, ...
1
vote
1answer
17 views

Detecting periodic patterns in data - how often are the meetings held?

Suppose some people I know frequently have meetings, and suppose I want to find out whether there's a pattern to when these meetings take place, and if so how often they occur. I can take note of the ...
0
votes
0answers
28 views

how can I find outliers in a 2 vector data set

I have a two data set $(X,Y)$ where $X$ represents the angles and $Y$ represent the signals. $X$ is always correct because I increment it by coding $x=x+1$. However, $Y$ could be sometimes wrong ...
0
votes
0answers
29 views

What is the relationship between the Fourier spectrum and the information content?

Suppose you look at the Fourier transform of some data (say, a blurred image). The amount of high frequency signal tells you how much texture there is in the data (e.g., a blurrier image has a more ...
1
vote
0answers
45 views

How can non-binary data be tested for distinguishability from random?

Given a large string of Base-N digits (in other words, not necessarily binary), is there software or an algorithm that can output whether the data is reasonably pseudorandom or reveals a pattern? In ...
0
votes
1answer
14 views

comparing empirical data to a model prediction using exponents

I am not a mathematician, but I have a basic question about comparing numbers with exponents near $1$. I am evaluating how well a "model" works and I want to make a compelling case. For example, my ...
2
votes
1answer
34 views

Predicting the increase/decrease of number

I have these entries in my database that looks like this: ...
0
votes
0answers
6 views

Scale a distribution to a new range and average

I've seen some linear scaling examples, but they don't really do what I want. I have a range of numbers from 0% to 126%, with an average of 75%. I want to map those to a range of 0% to 200%, with an ...
2
votes
0answers
31 views

How can I infer order from partially ordered discrete sequences?

A really interesting problem that I can't stop thinking about! Have run in to this a couple of times but yet to find a smart approach to either solve or frame this problem. This is my try at ...
0
votes
0answers
13 views

SEnsitivity Indices are non zero

I am trying to compute the sensitivity indices (SI) of a function using Monte Carlo simulation. I had written a matlab code that perform the computation directly and just return the final answer of my ...
1
vote
0answers
13 views

Help with finding an optimal bilingual skill-based routing calculation.

First time post, I'm not sure if it is in the correct forum but this seems to be as a good place to try: I was wondering if anyone out there had experience dealing with a similar issue or knew of any ...
0
votes
0answers
16 views

identify nature of missingness for categorical variables

could you please give me some hints for identifying the nature of missingness for categorical variables' missing value? I mean, I gave a fast search on google scholar but I didn't find anything ...
1
vote
0answers
13 views

Statistics linear modelling in R

Suppose I have a date set of the form: Test Subject/Sex/No. of mistakes made in the morning/ No. of mistakes made in the afternoon A / M / 2 / 5 B / F / 1 / 4 C / M / 3 / 5 D / F / 1 / 5 Suppose ...
1
vote
1answer
96 views

Unsupervised learning algorithms to detect anomaly in waves.

I have a sample of graphs (more than 10000...). that look like in the image below: I am searching for an unsupervised learning algorithms that can help me to detect anomalous observations. Here ...
3
votes
0answers
112 views

How does 2D kriging interpolation work?

I have a grid of points Example ...
0
votes
0answers
9 views

PCA: what if continous variables are frequencies

I've got a data set that exists out of 5000 variables and 6000 instances. Each element of the data sets describes a frequency. It's a documentTermMatrix. Now I would like to do some data reduction, ...
0
votes
0answers
9 views

Hurst exponent for decay evaluation

i would like to evaluate rate of decay of tail of my histogram. Expressing histogram on loglog plot gives straight line in the range where i have gathered a lot of data. Unfortunately the line is ...
1
vote
0answers
13 views

Curve 'anti-correlation' detection

If I have a data set, what algorithm can I use to detect when one curve moves in clear opposition to the majority of curves? For example: At point 15, the purple line moves up in opposition to the ...
2
votes
1answer
36 views

Entropy determination regarding lossless data compression

Suppose I had many computer data files to compress losslessly and wanted to know what is the theoretical limit to each one as far as minimum filesize possible. How would a math person go about doing ...
1
vote
0answers
31 views

Analyzing/Modeling DynamoDB Usage

I'm seeking the correct mathematical tools to analyze/model a real world process for the purpose of optimizing resource allocation. I want to analyze consumed throughput of a AWS DynamoDB table and ...
0
votes
0answers
32 views

solving T(n) = 4T(n/2) + n^3 + n*(log(n))^2

I am trying to solve a recurrence by using substitution method. The recurrence relation is: $$T(n) = 4T\left(\frac n2\right) + n^3 + n\cdot\log^2 n$$ i tried to solve this also with master method... ...
0
votes
0answers
28 views

Maximum Error Tolerances When Forecasting A Random Time Series

I have been working on an approach for forecasting random time series with a given maximum error tolerance for each forecasted point less than 10%-15% of the range of possible values. I have not been ...
0
votes
0answers
19 views

How can I apply inverse Abel Transform to a Data?

I have a data with X values and corresponding Y values. When I plot intensity map (2D histogram) of the data, I get a good image. I want to apply inverse Abel Transform to this image. How can I do it? ...
1
vote
0answers
16 views

Mean value of discrete periodic signals

It is clear that a continuous periodic signal always takes at some point $x_m$ the absolute mean value. Then we could define the absolute mean value of the signal as the value that it takes at $x_m$. ...
1
vote
2answers
30 views

Finding simplest function to distinguish 2 sets

I wish to find a function that distinguishes $2$ sets. I have m data values in form of n-tuples out of which k are supposed to be mapped to a value less than $0$ and other m-k are supposed to be ...
0
votes
0answers
16 views

Enlarge a 2d plot of f(x,y) while keeping the moiré patterns at the same size

I have some function $z=f(x,y)$ with $x,y,z$ real numbers. I wrote a script that generates a $600\times 600$ pixels plot of this function for, say, $0 < x < 1$ and $0 < y<1$, by mapping z ...
2
votes
0answers
25 views

How can I minimize the error from fitting two functions to different parts of data?

I have some data, and I expect that part of the data will fit to a power law, and part of the data to a line. Here's a made up example of some similar data: Where I've made the red part a quadratic ...
0
votes
1answer
17 views

confusion in percentiles

in definition of percentile, it is said that, some value is in 30th percentile means, 30 percent of the data values are lower than the given value. But my confusion is, what if I have 1000 data ...
0
votes
0answers
15 views

different data fitting methods

I have a list of 2-dimensional points and I want to know different techniques of arriving at an approximate analytic relation between y and x. Also important would be to understand how one technique ...
2
votes
0answers
38 views

Predicting profit with price variation

I am currently working on a high school project that aims to predict profit from X amount of items to Y amount of profit based off a deviated sale price. For instance: I sale 10 cookies for 10 ...
0
votes
1answer
58 views

How to interpolate between sets of data

I'm probably using the wrong terminology, making it difficult to find a starting point. I have a set of motor data that looks like this: I can easily create a trend line for a given flow rate ...
0
votes
0answers
36 views

Minimum number of periods to determine periodicity

Is there a minimum window window length to determine true periodicity with a given estimated period. For example, if the same event is tested for every second and is observed twice at times 1 minute ...
0
votes
1answer
66 views

Interpreting 3 Circled Venn Diagrams

The Venn diagram above represents the 20 students who took one or more of the 3 available art classes or took no art classes at all. two students took no classes at all. 1.How many people take only ...
0
votes
0answers
26 views

reducing data that are very close to one another

so, I have this problem. I have to do image analysis to get the boundary of an image. I perform image analysis to get a boundary representation of the object. The problem is, there is an overlap of ...
0
votes
0answers
19 views

Correlation method for speed measurement

I have data from two sensors on the road and I'd like to calculate the vehicle speed. The data are a bit noisy, so I was thinking about making a correlation of these data from two sensors with a ...
1
vote
1answer
70 views

Calculate 90th percentile of F distribution using “rchisq” function in R programming language

I am working on a problem for my Data Analysis class and I have to figure out a way to calculate the 90th percentile of the $F(3,5)$ distribution using the "rchisq" function in R(programming ...
1
vote
1answer
56 views

fastest and most efficent way to count all combinations in many sets and sum them together

I am a Java programmer who has reached the limits of brute computer power. My relational database (and non relational databases) is not producing results quick enough and I have hit a bottleneck in ...
1
vote
0answers
17 views

Find two clusters in an ordinated array

As the titles goes, I have an array of sorted real positive numbers, and some information on the structure of the data. I know that there are two constants $a>>b>0$ and two other numbers ...
0
votes
1answer
21 views

Chart Question and Percentages

The Venn Diagram above represents the 20 students who took one or more of the 3 available art class or took no art class at all. What percent of the students took only 1 art class? A. 10% B. 20% C. ...
1
vote
2answers
43 views

How to interpret the result of correlation between two discrete signals

Before starting, let me say I'm not a mathematician, I'm just a curious engineer, with a master's degree in engineering and computer science. I have been using this book The Scientist and Engineer's ...