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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38 views

Random walk in high dimensional space with stationarity

I have a vector of high dimension ( say 100). When I take a random walk ( i.e add a step value to each components of the vector, the step value being drawn randomly drawn from standard normal ...
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0answers
10 views

Minimal sufficient statistics for log-multiplicative/log-nonlinear models

I am interested in minimal sufficient statistics of Association models for variables for ordered categories developed by Goodman (http://doi.org/10.2307/2287833). In particular, consider an $I\times ...
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0answers
22 views

Number of clusters in $k$-means clustering for higher-dimensional data.

I've read the Wikipedia article and a lot of posts on stackexchange (like this really thorough one) on determining the number of clusters in a data set. Based on that, I am currently using the ...
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0answers
16 views

Calculate the difference of binary vectors

I have a matrix with 579 columns (points of data) and 138 rows (objects I am comparing). The points of data is binary - either it matches or it doesn't match. I am working under the assumption that ...
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1answer
33 views

Proving relations between square cosines

I am studying data analysis and especially PCA (principal component analysis) and reviewing the very course i took a few years ago, i found a result that seems interesting but there is no proof and i ...
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2answers
60 views

Approximating statistics for huge dataset

I'm investigating users accounts statistics for Vkontakte social network. There are $N\approx2 \cdot 10^8$ accounts that have different metrics along them – boolean, discrete and continuous. I found ...
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2answers
40 views

Is this histogram considered bimodal?

Is this histogram bimodal? Because when I google what a bimodal histogram looks like, I keep getting images that say histograms like these are considered bimodal. Isn't it unimodal because the ...
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4answers
51 views

What is the purpose of finding a model to best fit data?

So given the following question: What is the purpose of finding a model to best fit data? Someone answers: The purpose of fitting data to a curve is so that you can give an exact statement about ...
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1answer
24 views

Can I apply a one-way ANOVA and Tukey test to this data?

The experiment: Effect of pH on yeast respiration. I tested 5 different pH levels and measured the amount of CO2 produced. The data shows a trend similar to upside down parabola. Would it make sense ...
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0answers
17 views

Generating stastical model from taxi dataset

From the dataset available here of NYC taxi journeys I wish to create some kind of model that will allow me to estimate the probability that a request comes in in a given time interval (on the order ...
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0answers
17 views

Warp shape and texture of the image into a common reference frame

I want to find object on the image using ASM and after that warp segmentation results into a common reference frame. So, I already have the algorithm of PDM and ASM and I able to find shape of object ...
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1answer
41 views

How to find equation of a curve from points

I have got a curved line that I would like to find the equation of using Microsoft Excel. The curve seems to be either a polynomial or some sort of a trig graph. I've done some research and looked at ...
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26 views

The definition of an equivalence relation in persistent homology

I am reading a paper by Carlsson on "Topological pattern recognition for point cloud data." I was having a little trouble understanding the formal definition of an ...
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1answer
24 views

Generating a deterministic random function that takes into account the date as well as a long ID

In SQL Server there's a function RAND() that if you pass a seed to it will return a pseudo random number based on the seed. No matter when you pass that same seed into this function, it will always ...
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0answers
14 views

What are the Data type for the following data set

Dear users i would like to know what are the data types of the following data set: this data set are classified the documents based on some topics , ...
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0answers
13 views

What are the appropriate statistical tests for an optimization experiment?

I recently conducted a chemistry experiment where I tried to find the optimal sugar concentration for the fastest respiration of yeast. My data looks like this: I don't have any values between 50 ...
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0answers
10 views

Using a rank sum procedure to test for differences/constructing a confidence interval for difference of medians

I was recently given a problem in which to analyze different seedling growths. I have placed my data into MiniTab combined the two groups and ranked them. This is where I am becoming a little ...
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1answer
21 views

Calculating 5 different ranges for people resource management

I am working on a project for my company. My team is building a project charter template. In this template needs to be a drop down that estimates how many full-time employee days(FTE) will be ...
3
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1answer
30 views

Median of Medians

Given a set A with median Am = 10 and set B with median Bm = 20 is it true that the median of the combined set C is $10 \le$ Cm$\le 20$ ? My first thought was that this wasn't true so I tried to find ...
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5answers
63 views

Prove a function is in Big-Oh and not in Big-Omega

We are told to use the definitions of Big-Oh and Big-Omega to prove that a given function is in $O(f(n))$ or $\Omega(f(n))$. It requires being able to use $c$ and $n_0$. Use the definitions to show ...
2
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1answer
49 views

Obtaining quadratic equation using Least Squares Method

This question is most likely extremely trivial, but I'm having some difficulty obtaining the least squares equation from the following data points: {{1.08, 0}, {1.07, 0.0659232}, {0.97, 0.1695168}, {...
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0answers
40 views

Mixing Fuzzy Logic and Probabilistic interpretation of a dataset

A probabilistic data cloud is a set $M$ of data points $\{m_i\}_i$, where each data point $m_i$ is associated to an event $E_i$ expressing the set of the occurrences of $m_i$ in any possible non-...
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0answers
20 views

Relationship/correlation between data - does it exist?

Data I refer to in this question Some analysis has been conducted for my business by an external company. The data, as it stands, only really tells part of the story and doesn't provide any real ...
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1answer
44 views

Finding relation between inputs and outputs

Is anyone able to find the rule? If possible, can you explain how and what's the name of that kind of rule? Input Output 0,18 0,316 0,3 0,432 0,32 0,4536 0,33 0,4644 0,34 ...
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0answers
18 views

Continuous/interpolating alternative to order of magnitude?

Define $\operatorname{magnitude}\left(x\right) = 10 ^ { \lfloor \log_{10} x \rfloor }$ and $\operatorname{magnitude'}\left(x\right) = 10 ^ { \lfloor \log_{10} x \rceil }$ Currently I'm using this $\...
3
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2answers
50 views

How to pick the “best” line equation that fits data and passes through the origin?

I have some data shown in the image. Each symbol corresponds to a different dataset. As it can be seen the data initially behaves like a line and after some points it follows other behaviour. The ...
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1answer
159 views

calculation of median of grouped data

While calculating the median of grouped data of total frequency $N$, in order to find the median class which value should be taken into consideration to match against cumulative frequency : $\frac N2$ ...
2
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1answer
45 views

Fitting a curve given points

My set-up is the following, I have two variables $N$ and $TTR$, and I have these points for each variable: $N$ = [35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50] $TTR$ = [0.818, 0....
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0answers
11 views

Distribution for frequency data

I am conducting statistical tests on a large set of frequency data. The frequency data is in the form of times of occurrence of events at a number of locations. Locations can be assumed to be ...
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1answer
30 views

Finding the number that's less than 90% of result set

Forgive if this sounds vague or poorly worded. I'm struggling to pinpoint the right terminology of what I'm looking to do. Hoping someone here can push me in the right direction. So I have a set of ...
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1answer
77 views

Determine equation from graph

Background: I'm working on a script to read/parse a file generated by a piece of software I use to create music mixes. One aspect I'm having difficulty with is translating the volume value from it's ...
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0answers
38 views

Calculating Average “Productivity”

Let me apologise in advance if my terminology is incorrect or if what seems logical to me is completely nonsensical. I am an analyst without a mathematical background and have tried to self teach off ...
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2answers
38 views

How sensitive is a natural cubic spline?

I am interested in using natural cubic splines to generate possible replacement values in the quality control of data. I would like to do this as close to real-time as I can. That is, I would like ...
2
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1answer
30 views

How to describe a statistical dataset more precisely?

I am a newbie in stat and I need to be able to do this for a GIS application: Say I have the following dataset of only two possible values $0$ and $1$: $0,0,0,1,1,1,0,1$ The mean would equal $\frac{...
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0answers
15 views

Is data normally distributed over attributes or need to be normalized ( scale )

I have been spend lot of time related to my data distribution, for the following matrix, there are need to cluster similar factories as follow : - each factory made some products for example : factory ...
1
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1answer
97 views

On normalized error measures

I have function values $f_1,\ldots,f_n$ that are approximated by data $y_1,\ldots,y_n$. I am looking for a measure that describes the error in the data $y_1,\ldots,y_n$ and I want the measure to take ...
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0answers
14 views

replicating a probability model for classification

I'm trying to replicate a probability model for a binary classification based on some data. Until now I been able to replicate the left panel, the histogram and the gaussians curves, but I dont know ...
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0answers
10 views

Building agglomerative hierarchical clustering algorithm manually

I am currently trying to solve this problem but I'm quite unsure if my answer is correct. I've build the tree different types of measures, MIN, MAX and AVERAGE but I might have some of them wrong. Can ...
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0answers
11 views

Complementation Rule for MVDs

I have that $X \rightarrow \rightarrow Y$ is a Multivalued Dependency in $R$ and let $Z=R-(X \cup Y)$ With $t_{1}[x]=t_{2}[x]=t_{3}[x]=t_{4}[x]$ $t_{1}[y]=t_{3}[y]$ and $t_{2}[y]=t_{4}[y]$ $t_{1}[...
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0answers
16 views

Comparing Temperature Curves

I'm collecting a bunch of temperature data from water cool down tests and need some advice on how to best compare data from different tests. I have a test stand and as I change test variables between ...
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0answers
13 views

Bayesian model to estimate the parameter of a Bernoulli law

Suppose we have iid boolean variables $X_1,...,X_T = X_{1:T}$ and the associated deterministic parameters $k_1,...,k_T=k_{1:T}$ and $c_1,...,c_T=c_{1:T}$, where for each $t \in \mathbb{N}$, $k_{t} \in ...
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1answer
60 views

Stem and Leaf Plot for Strongly Skewed Data

How to draw a stem and leaf plot for the following large data, the data is for different EU states so there is a large difference between the data. I have to plot stem and leaf for each table i.e. ...
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1answer
62 views

File Compression Statistics

Statically, how is the compression of a file possible? As in, a file n bytes long can have $2^{n*8}$ (the 'times 8' part is because there are 8 bits in a byte). So, if you decrease the size then ...
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0answers
21 views

Data Management Frequency Interval

I am given the results of 30 students for a Data Management test: $78, 81, 55, 60, 65, 86, 44, 90, 59, 81, 77, 71, 65, 39, 80, 72, 70, 64, 68, 78, 88, 73, 61, 70, 75, 96, 51, 73, 65, 67.$ The ...
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0answers
24 views

Ordinal scale: does aggregating data by arithmetic mean is a concrete problem?

Sometimes when people have some ordinal values, they use a misleading number representation. Then, they aggregate data with arithmetic mean. For example, we have to aggregate the grades of an exam ...
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0answers
12 views

Introducing weights into spectral clustering

Suppose I have a data set with points $x_i$ and a dissimilarity measure $d_{ij}$ between each pair, as well as a weight $w_{ij}$ that qualifies the quality of this dissimilarity. I have two problems: ...
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59 views

How to do Modified Mann Kendall test for trend analysis?

In mann Kendal trend analysis if auto-correlation in the time series exist we do pre-whitening to remove the affect of lag-1 correlation. However, it has been reported that pre-whitening reduces the ...
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0answers
15 views

Find repeated attribute patterns in collection of objects

I have objects $o_1,...,o_k$where every object has a set of properties $p_1,...,p_j$. I'm looking for property patterns that are repeated among these objects. It could be perhaps called correlation of ...
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0answers
19 views

Ortogonal polynomial regression

I need to fit a weighted set of points with orthogonal polynomials based on least squares polynomials. The grid on X is nonuniform, so Chebyshev polynomials can't be applied. The data points are like ...
1
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1answer
75 views

Cauchy Schwarz inequality in Normalized Cross Correlation

I'm currently using a normalized cross correlation(NCC) for measure the degree of similarity between two image. Almost two week studying about how NCC is derived from Cauchy Schwarz inequality but ...