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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9 views

How to find saturation point of a four parameter S curve?

I want to find the saturation point from where the S-curve values remain constant for a four parameter logistic equation i.e Alpha, Beta, Inflection and Slope are provided.
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4 views

Analysis of rank/likert scale data

If age groups/gender represents independent variable(s) and responses have been collected for 5-6 items in the form of ranking (most preferred - rank 1 to least preferred rank - 5). Which test is an ...
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0answers
17 views

Markov-Chain Monte-Carlo: Are transformations on the inputs valid?

The problem: I am trying to solve a high dimensional (up to ~50) class of data fitting & modelling problems. The user specifies the problem, so I would like to make the configuration as easy as ...
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0answers
9 views

Finding trends in data with multiple variables, analysis software?

I have a series of many test results (hundreds). They are vibration test results of electronic equipment that has been built the same standard way (same materials, adhesives, structural shape and ...
2
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2answers
89 views

weighing avg by columns vs rows outputs different results

First of all, I just know the basics of math, so please be patient. I have an overall score for a company with the product1 and product2. However when I do the overall for each criteria like ...
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0answers
14 views

How can I determine an efficiency equation for this problem?

At work, I have been tasked with taking all of the relevant information regarding our production lines in order to determine the efficiency of all of our assembly lines. Below is some of the criteria ...
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1answer
35 views

How do I find if a series of integers is (somehow) regular

[DISCLAMIER]: please be patient and low profile: no math background here :) I have a database of transactions, i.e. a list of purchases made by different customers. What I have to figure out is ...
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1answer
20 views

Curvature of a 3D trajectory for which I know data points

In order to simulate an airplane model, I need to change its orientation knowing the curvature of its trajectory. The simulator gives me the plane position, so in order to perform my orientation ...
0
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0answers
25 views

Can I solve these simultaneous questions, and if so, how?

I have a set of paired experimental observations (Fo, Bo), e.g. 1.55, 8.52 4.56, 36.36 21.03, 64.98 (> 6 data pairs in total) which I believe can be modelled as being generated by Fo = Ft + a.Bt ...
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0answers
31 views

Interpolation at “extreme values.”

I am working with a meteorologist on a project. We are pulling data from METAR Observation stations on several variables (such as temperature, dew point, wind speed, etc.) throughout time. ...
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0answers
6 views

Statistical Significance of Modified Data

I would like to know the statistical significance of achieving 1 or 7 100% of the time in a dataset of nine possible values. The nine possible values are the digital roots of a string. In a random ...
1
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1answer
23 views

Non-Whole Median Numbers in Real Data [duplicate]

According to this CDC report, the median number of reported sexual partners for females aged 15-44 is 3.2, and for males 5.1. Tables on pages 19 and 20 report these statistics for a variety of ...
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0answers
23 views

Matlab, Extracting Particular Values from an Excel File

If I have a table of values in Matlab ( here I have a 40k rows, and about a dozen columns), how can I read only particular values from each row? My goal is to extract some of the values from each row, ...
0
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0answers
22 views

intersection of 2 paths

Could somebody please advise me on the best approach to take to find the intersection points of 2 paths. Each path is a data set of distance against time (I want to avoid curve fitting) and each path ...
1
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0answers
19 views

Averaging Models in Excel

I am working in Excel and have two sets of data points that come up with a percentage for the likelihood of a recession. I am wondering what the best strategy would be to combine these data points? ...
2
votes
1answer
39 views

Calculate trend and represent in text?

First off, I'm terrible at math. I'm writing a script that monitors transactions from clients daily over a 7 day period. Given a set of numbers like below, I would like to calculate a trend and ...
0
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1answer
19 views

How to convert table into a distance function?

Been stumped on this past paper question for a while, it's in the context of clustering and the next part is using single linkage bottom-up hierarchical clustering to form a dendrogram using your ...
0
votes
1answer
27 views

How can I maximize the sum of y values across a given number of graphs?

I have any number of graphs. Each graph is a plot of points, not necessarily an equation. I need to pick a point on each graph in way that the following is true: The sum of the y values of each ...
0
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1answer
21 views

Slightly convoluted problem I need help solving involving the percent change formula.

I was hoping someone knows the solution or has an alternative form of approach. tried this out over on /r/askmath with little response. Ok I will attempt to be as clear and as simple as possible. I ...
0
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1answer
28 views

Probability of a Collision in Selection of Permutations

Suppose I have a set of characters, say $\{a-z,A-Z,0-9\}$ $(n=62)$. Then I select a random permutation each containing $10$, e.g. $k=10$, characters. What would be the probability of a collision ...
0
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0answers
57 views

Deal with circular standard deviation

I have a sensor that gives me a direction of the target in degrees with a certain standard deviation and I use a circular probability density function (PDF) to represent probable locations for the ...
2
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2answers
42 views

Inversion of the Burrows Wheelers Transform

The "Burrows-Wheeler Transform" in signal processing is a transformation which is used in for instance data compression and pattern recognition. It can be described in mathematical terms as: Start ...
3
votes
1answer
21 views

Clustering elements according to covariance matrix

I'm doing a little bit of topic modelling (which is not really my area) with twitter tweets. The situation is the following: I have a (sort of) covariance matrix where the entrie $C_{ij}$ corresponds ...
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0answers
14 views

Methods for Extrapolating Data Close To Observations

I am aware of many different ways to go about interpolating between the values of known data points. However, whenever I come upon (I work in Quantitative Finance) the need to extrapolate data I find ...
0
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0answers
12 views

Random data generation from a bivariate distribution

Let $X$ and $Y$ be non negative random variables with joint distribution \begin{equation} F(x,y)=1-e^{-x}-e^{-y}+e^{-x-y-\delta xy}; ~~~x\geq 0,~~y\geq 0. \end{equation} How to generate a bivariate ...
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0answers
4 views

How do I find the weighted mean of maxima for a granulized data set?

I have a dataset for which I had to apply Wang-Mendel algorithm. The aim is to find the y value when x=14. I granulized and approximated the data and found the rules in the Mamdani format. Now I have ...
2
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3answers
60 views

Parameters estimation for gaussian function with offset

I've read the paper Least square fitting of a Gaussian function to a histogram by Leo Zhou on how to perform a Least Square Fitting of a gaussian function to a histogram. The Gaussian function used ...
4
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2answers
599 views

Way to compare three numbers with an algorithm.

Say I have values 10, 3, 6 What would be a way of finding a subjective difference between them. Or in other words, how close they are to each-other. So if i had 3, 2.5, 2.8; they would be close ...
2
votes
1answer
24 views

make the mean of 2 data sets the same

I am in the process of computing my student's final scores and for some reason I couldn't figure this step out: If I have 2 data sets of scores in the range [0,40] but one data set has a different ...
0
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0answers
26 views

Representing a Concept

From Formal Concept Analysis: If I have a set of objects: G={Shark, Penguin, Bat} and a set of attributes: M={Breathe Underwater, Can Fly, has Vertebrae} and I make a chart to represent my ...
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1answer
48 views

Using Excel to calculate relative difference between three numbers

Background I am trying to produce a table of values for the positioning of the hands of a clock at any time, limited by one second intervals, to demonstrate the feasibility of an ultra precise, ...
0
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1answer
37 views

Function to convert all -ve numbers into their +ve counterparts without affecting present +ve values (-12 to 12)

I am essentially after a function that will convert negative values in my Excel spreadsheet into their positive equivalents without affecting the present positive values. A sample of my data would ...
0
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0answers
36 views

Mathematical equivalent to curve fit between polynomials

I am adapting a calculation done in an Excel workbook to code. Right now, we are predicting a variable based on three other variables, say $x,y,z$. We are creating six functions of $x$ and $y$ at ...
0
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1answer
35 views

Interpreting Entropy

All you data scientists will probably know the entropy equation: $$H(p)=-\sum_{i=1}^{n}{{p}_{i}}\cdot\log_{2}{{p}_{i}}$$ And, using this, I was messing around with some compression, and calculated ...
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1answer
11 views

What measurement should be used to determine per unit capacity of a given volume ish question

I am reselling data packages and would like to add a sense of scale to the packages. Without disputing actual numbers, an email message is between (3-20)Kbytes, a photo 270kb, a web page ...
0
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0answers
10 views

Is it always possible to find a logistic regression model that yields zero training error on any dataset?

I am leaning towards no. A logit regression model is just one function, and there is no way its coefficients can accurately predict an entire dataset, outliers and all. Is this the correct intuition?
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2answers
59 views

How to verify how good my data is?

I'm in an undergrad physics lab right now and I have taken some data. The theoretical curve should be proportional to $\cos^2(\theta)$. How can I quantify how close my data values are to this ...
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0answers
14 views

When to use the various mean functions (arithmetic, geometric, quadratic) appropriately?

In data analysis, when are the use of these different means appropriate? For example, I'm using data to infer the peak of waveforms at different points around a semicircle. If my data has intensity ...
0
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0answers
9 views

Montonicity and Nonlinearity in data

I wish to find out why the following function $y_i=\sum_{l=1}^N\frac{ \theta_l}{1+ \exp-(\sum _j^M \theta_j x_ij +b_j ) }, i=1,\dots, P$ shows a linear, monotonic relationship instead of a ...
1
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0answers
35 views

Data analysis: How did people beat the Great Hall game?

This is the game: There is a Great Hall with 102 doors. 100 of these doors lead to one of 100 different side rooms. The 101st door, at the end of the Great Hall leads to the Great Tower, where ...
4
votes
2answers
76 views

Chaos theory and fractal geometry: Constructing from data

I understand that fractal geometry represents behaviour of 'chaotic' system, if I am not wrong. And also, fractals are generated by a recursive function. But, lets say I have random data lying with ...
0
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0answers
9 views

Accurate numerical integration for “data times an analytical function”

The Question is as follows: I have an algorithm/data that provides me the value of a function $f(x,y,z)$ on the points of a grid. On the other hand I have an analytical function ...
0
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0answers
62 views

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 ...
0
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0answers
19 views

How does Link Analysis work?

Currently, I am into Link Analysis in data mining. I am kind of having a hard time to understand the Link Analysis. I have studied Association Rules and this is my next goal to understand. I have been ...
1
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0answers
55 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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0answers
21 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 ...
0
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1answer
27 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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0answers
8 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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0answers
31 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 ...
0
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0answers
17 views

Statistics, distributions and graphing

Lets say that you have data containing one variable - the waiting time between each car passing from 1200 hours... so you have something like 23, 54, 26, 8, 2, 59 etc what is the best way to analyse ...