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.

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Peak Picking in Spectrum Data (MS Excel)

I'm working often with spectral data of various gases, and the bulk of the data analysis is assigning the peaks with maximum signal (y-axis) to frequency (x-axis). Often we have several thousand data ...
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99 views

How can I interpolate the following data and get the equation?

I want to interpolate between three vectors which have 8 rows in each. For eg. X = [1 2 3 4 5 6 7 8], Y = [7 8 9 10 11 12 13 14 ], Z = [15 16 17 18 19 20 21 22] I want to find the equation Z = ...
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28 views

What is the name (if any) of this statistical analysis concept?

I have a list of random numbers. I sort them, and designate each one as belonging to a tier of some sort (quartiles, percentiles, or even arbitrary cutoff points by proportion) based on the ...
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1answer
43 views

bias-variance trade off

Perhaps the most primitive (and yet very effective) way of estimating a density is by using a histogram. In a histogram, we can manage the 'precision' of the distribution by adjusting the number of ...
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10 views

Translating data query into Domain Relational Calculus

Given a following table named BOOKING, which contains three columns, guest_name, room_number and booking_date, how do I find the all the guest_name that have the same room_number and booking_date? I ...
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42 views

What function should I use to fit this data? Logistic function is not good enough fit.

I'm using curve_fit from numpy to try an fit some data I have. The function I used was the logistic function defined http://en.wikipedia.org/wiki/Logistic_function and the parameters I picked were ...
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18 views

Determine the multi-dimensional relationship given the data

I have a dependent variable - A and 3 independent variables, H,V and N I have a data for all the variables and dependency relationship is based on my operational knowledge. I'd like to know what ...
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1answer
72 views

Application of wavelet analysis in computer science

I am doing research in computer science (data mining), do you think wavelet analysis is useful for me?
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339 views

How can I get the covariance just given the variance?

This is a fairly straight forward problem but I don't know how to calculate the covariance given just the variance of X and Y. Suppose X and Y are independent random variables such that Var(X)=1 and ...
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60 views

What is the related function between these point?

What is the related function between these point? $(1,5)(2,7.5)(3,8.75)(4,9.375)(5,9.688)(6,9.844)$ $y=ab^x$ does not relate?
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1answer
62 views

Linear Regression Application

I have a linear equation as follows: $B_0*x_0 + B_1*x_1 + ... + B_8*x_8 = result$ And i have about 200 different situations that are categorized into two different groups, depending on whether ...
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43 views

Noise Reduction

I'm working on a problem that involves production rate data from oil wells. These rates are recorded per month i.e. after a month of production the produced volume is calculated and reported as rate ...
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4answers
357 views

Why do graphs sometimes have unevenly spaced intervals in axis e.g. logarithmic

Why do some graphs not have evenly spaced out units on the x or y-axis? For example they have log on one or both of the axis? Here's an example from this page I guess the page does give a bit of an ...
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49 views

Is Principal Component Analysis applicable to this type of situation?

I'm trying to model the response of ant populations to pheromones in this way: The ants are simulated as Self Propelled Particles with internal energy. They undergo acceleration due to their internal ...
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26 views

Method for measuring co-occurence

I have a dataset that lists a large number of binary variables for each member of the populations. It basically looks like this: ...
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30 views

Predictive models

Given a set of temperatures of different cities for a month, which prediction model should I use for a two day look ahead prediction? Regression models or Time series?
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1answer
25 views

rotating and exchanging x for y's in regression

I was just wondering what happens generally if i send all my x points to y's and y's to x's (i.e reflect along the y=x line) - if I change the x's and y's will my old error minimizing line still be ...
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27 views

Compress Unit ID Permutations

For my multiplayer RTS game, I need to send over the ID's of a player's units selected in a single integer. For every player, there are 16 units, each with an integer ID between 1-16 (inclusive), and ...
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1answer
80 views

$P(X > \mu + \sigma) > 0$?

I'm doing some data analysis. Let $X$ follow an unknown distribution, with a certain average $E[X]$ and a standard deviation $\sigma$. Both values are calculated using the (corrected) point ...
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2answers
537 views

How do I find the missing sample points with the Mean and Sample Standard Deviation?

I am completely lost on this statistics question: A statistician had a data set containing 13 data points written in his research notebook. He spilled coffee on his notebook and now he cannot read ...
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2answers
184 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 ...
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0answers
192 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 ...
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1answer
59 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?
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2answers
61 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 ...
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1answer
23 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 ...
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0answers
95 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 ...
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1answer
37 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 ...
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1answer
51 views

Predicting the increase/decrease of number

I have these entries in my database that looks like this: ...
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47 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 ...
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16 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 ...
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1answer
110 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 ...
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0answers
356 views

How does 2D kriging interpolation work?

I have a grid of points Example ...
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19 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 ...
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1answer
95 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 ...
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174 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 ...
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116 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 $x_m$. ...
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2answers
50 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 ...
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19 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 ...
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0answers
69 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 ...
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1answer
38 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 ...
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0answers
70 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 ...
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1answer
205 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 ...
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1answer
131 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 ...
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1answer
129 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 ...
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1answer
107 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 ...
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0answers
20 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 ...
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1answer
36 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. ...
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2answers
78 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 ...
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1answer
334 views

Least squares fitting using cosine function?

Hello I am trying to fit a harmonic of the form $$y = b + c\cos(x)$$ to four data points (0,6.1) (.5,5.4) (1,3.9) (1.5,1.6) using least squares for homework. I know that the error $= Y_i - f(x_i)$ but ...
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1answer
49 views

What statistical analysis to use on a list of dates?

I suffer from migraines and for many years I've kept a log of each attack. I now want to do some analysis on the dates of each attack to see if there are any patterns. I intend to check the ...