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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1answer
22 views

How do I handicap a leaderboard?

In a game scenario, where each player can score points based on the number of "opportunities" they are given, but where some players have many more "opportunities" than others, what is a good way to ...
0
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1answer
78 views

Need help with Lagrange Multipliers in Support Vector Machine

In linear support vector machine with binary classification if we know all the support vectors, geometrically we can create hyperplanes on both sides of the main hyperplane using these support vectors ...
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0answers
94 views

Normalizing data between 0 and 1

I've got some data that I need to be normalized. I've tried several different ways I've found online, none of them work the way I'd like. I've tried ...
2
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1answer
124 views

Techniques to find regression parameters for multiple datasets where a subset of parameters should be the same for all datasets

I have five sets of observations of measured y as some function of measured $x_1, x_2, x_3,\ldots$ and I want to fit five functions to these observations. They have the form $$ y = f(x_1, x_2, ...
3
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2answers
4k views

Value range of normalization methods? min-max, z-score, decimal scaling

I am working my way through Normalization (data transformation) of data and was curious about four methods: min-max normalization, 2. z-score, 3. z-score mean absolute deviation, and 4. decimal ...
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0answers
89 views

Least squares fit or decomposition of average points (from data)

I have a set of data consisting of the averages of a function $g(r)$ at regular intervals; i.e. my first datapoint is the average of the function from $0$ to $\Delta r$, the second point is the ...
2
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0answers
155 views

Kalman filter for acceleremoter and gyro

I have read a lot of literature on this topic, but many questions still remain. (Many formulae are here below, so, who prefers to look at them in a more comfortable manner can find a MathCAD sheet ...
2
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1answer
155 views

Lloyd's algorithm in normed vector spaces

How do I run Lloyd's algorithm in a normed vector space? The space: L*a*b* color space, finite sRGB segment, $R^3$ The distance metric: CIE94 using L*C*h* information derived from the L*a*b* ...
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2answers
2k views

Find the median given a table of relative frequencies

I came across the following GRE question. I had no problem finding the mean. However, the answer for the median is given to be 1. I don't understand how they arrive at this.
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1answer
24 views

Rate of Growth of pyramid structure.

This might be simpler than I'm making it out to be, but how can the growth rate of the pyramid structure be represented. ...
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2answers
71 views

Numerical integration of a derivative dataset

I have an experimentally measured derivative data ($\frac {dy}{dx}$) at a range of times i.e $\frac {dy}{dx}$ for $0 \le t \le tf$. Integrating for $t=0$ is fine, since $y(x,0)$ is known. However, ...
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0answers
42 views

How to understand the task about bootstrap?

I have the following task. Let $X_1,\ldots,X_n$ be a sample (i.i.d.), $T_n = \overline{X}_n^2=\left(\sum\limits_{i=1}^nX_i\right)^2,$ and $\hat\alpha_k ...
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0answers
136 views

Choose a right optimization method

I have a question related to optimization method selection. Suppose now I have some observation data (1D) as well as the underlying function model. For example, I use the following codes to generate ...
0
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1answer
151 views

How to determine a function from outputs

Given the following inputs and outputs to a function, how would I determine an algorithm to fit? ...
0
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1answer
202 views

Normalize data with large spread in values.

I'm currently trying to rank a set of data. The issue is that my initial rank comes from a search on google and the returning result set. The spread in values is ranging from 33 all the way up ...
1
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0answers
39 views

problem in dimensionality reduction

I am using multidimensional scaling to plot my data in R. However there is a hierarchy in my dataset which i want to exploit and I am using the delaunay triangulation to visualize the plot. So now I ...
1
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1answer
158 views

Mathematical calculation to regenerate numeric series

I am searching for a mathematical technique by which I can perform the following, Let me explain first what i want to do. consider a numeric series: ...
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2answers
3k views

Use a set of data points from a graph to find a derivative

I have a data logger that is recording the temperature readings from thermocouples at a specific interval. This gives me data points that I can graph where the x-coordinate is time and the ...
0
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1answer
107 views

Dividing data of a given distribution

Having a dataset with distribution $p$ (e.g. uniform or normal), if we divide the dataset into $n$ parts with equal size, is it valid to say that each part still has distribution $p$?
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1answer
95 views

noisy 1-second GPS data [closed]

So, I come from a programming background, but not a mathematical one. I have a problem that I'm sure has a great mathematical solution! so, I have GPS data points for every second of a drive a car ...
1
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1answer
37 views

Box Plot Log Scaled?

When making box plots to represent data, is it logical to set our axis scale to logarithmic? Or does that defeat the whole point of a box plot?
1
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1answer
227 views

Group mean vector and common group covariance matrix in discriminant analysis?

I'm looking over the answers for old statistics exams in preparation for my own exam, while reviewing a question concerning discriminant analysis I found something really odd. I have input variables ...
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0answers
42 views

What is the name of the matrices which reorder edges in an adjancency so that they are closer to the diagonal? (modularity/structure)

I have seen adjacency matrices presented where the edges formed box like formations along the diagonal (not block matrices). This helped view the modularity and community structure of the group of ...
1
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1answer
84 views

Comparing two ratios with tolerances

I'm trying to figure out what the most robust way to compare two ratios is. What I have is a set of proportions between two or more quantities. For example, it might be 0.5:0.5, or 0.45:0.2:0.35. Then ...
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0answers
142 views

Classification: Why k-Nearest Neighbor method is more appropriate for a Mixture of Gaussians?

I'm reading a book named "The Elements of Statistical Learning" in which it states 2 scenarios when we are trying to predict the class label: Scenario 1: The training data in each class were ...
2
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1answer
56 views

Find data to perform regression analysis

I'm trying to find some data (two continuous variables that I believe are correlated) online for which I can perform a regression anaylsis, my assignment sheet says: The data may be found anywhere ...
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0answers
26 views

Extrapolating parameters for a fit different from the one originally used for regression analysis (no longer having access to data)

Say I have some data, I assume a fit of the form: $\alpha_1 e^{\beta_1 k}$, and I extract some values $\alpha_1>0$ and $\beta_1<0$ for $k=[1,\ldots]$. Say this appears to be a "near perfect" ...
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0answers
100 views

How can I create a good subset of data proportional to the full data set

I am programming a neural network and I need to use some data to train it. I am following the steps of an experiment which tried to predict direction of stock price index movement using neural ...
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0answers
32 views

How to find BUE of N? where $X_i$ iid $ P(X_i=j)=1/N$, for $j=1, \cdots, N$

Let $X_1, \cdots, X_n$ be iid with $P(X_i=j)=1/N$, for $j=1, \cdots, N$, where $N$ is an unknown positive integer. I would guess that the order statistics $X_{(n)}$ is the complete sufficient ...
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0answers
18 views

Linear trend has to pass through a point [duplicate]

Possible Duplicate: Linear trend has to pass through a point I need to interpolate a linear trend surface through a number of points but with the condition that the surface has to pass ...
0
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0answers
131 views

Test of goodness of fit - normal distribution of file sizes on HDD

I'm trying to prove, that sizes of files stored on HDD comes from normal distribution. I already made a java code that gave me list of all files on disk with filesizes in Bytes: ...
2
votes
1answer
370 views

Data Type Classification in Statistics

It is my understanding that in statistics one has 4 basic data types: nominal, ordinal, ratio, and interval. I see cases where people refer to "count data" (which is a random variable whose range is ...
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4answers
306 views

Can you help me solve these questions related to a Logical theory?

In a group of 200 people, number of people having at least primary education (assuming - Category I): number of people having at least middle school education (Category II): number of people having ...
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1answer
66 views

Determining Sample Size - Design Problem

I have a hypothetical problem were say I have a sample size of about 5000 people. I then will collect data on them say, how man calories of food they eat per day for a month. Now I can't obviously run ...
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1answer
102 views
0
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1answer
73 views

algebraic expression for a counting function

consider a 2d "counting" function given by the $(x,y)$ points/pairs: (1,1), (2,2),(3,2), (4,3),(5,3),(6,3), (7,4),(8,4),(9,4),(10,4), (11,5),(12,5),(13,5),(14,5),(15,5), ... ie $x$ increments in ...
9
votes
3answers
293 views

Removing noise when the signal is not smooth

Suppose we have (an interval of) a time series of measurements: We assume it can be explained as a "simple" underlying signal overlaid by noise. I'm interested in finding a good algorithm to ...
-1
votes
1answer
63 views

What is the name of this data normalization?

I have a two-dimensional array ($569\times30$ double) which should be normalized using this formula: $x'_{ij} = \dfrac{x_{ij} - \overline\mu_j}{\overline\delta_j} $ What is the name of this ...
0
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1answer
64 views

Finding outliers in a linear series

I have a series of observations made against time. Given perfect observations, the trend should be reasonably linear. As I expect there to be measurement errors, I wish to exclude them from further ...
1
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1answer
262 views

Error in a numerical derivative

I have a graph of data, say temperature ($T$) vs time($t$), I know the error bounds in each $\Delta T$. The range of t is from 0 $\to$ 1600 s, with small steps say 0.001 s. If I numerically take ...
0
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1answer
51 views

Determine a curve's dominant direction over time

I have a sequence of numbers in a certain order, for example {60,61,62,1,63,,64,102,65,66,200} If this is drawn as a graph, this will be a curve going upwards, but with some aggressive jumps upwards ...
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2answers
783 views

What is the distribution of a data set

I understand what the probability distribution is. I also have a personal understanding/interpretation of the concept of distribution of a dataset. Whenever I see this expression I imagine a graph ...
3
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1answer
389 views

Abstract Algebra for Business Intelligence / Data Mining

Twitter released its Algebird library, an abstract algebra library for scala. At a high level, what are the maths involved in abstract algebra that have an impact on aggregating large datasets?
3
votes
2answers
94 views

How do I use specific data points on a graph to determine an equation?

I need to find a function $f(x)$ such that the following data points would fit on it: $$f(1) = 0 \\ f(2) = 0.5 \\ f(4) = 1.0 \\ f(8) = 1.5 \\ \cdots $$ and so on. So the pattern is every time $x$ ...
0
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1answer
124 views

Microsoft Excel not graphing, $x = y^{1/2}$

Im not sure if this is a math question or a su question. The experiment was relating the period of one "bounce" when you hang a weight on a spring and let it bounce. I have this data here, one ...
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0answers
40 views

Fitting multiple functions with shared parameters to data

consider a set of real-valued continuous functions $$f_i(t;a)$$ for $1\leq i\leq n$ with some shared non-negative parameters $a=(a_1,\ldots,a_d)\in\mathbb{R}^d$. Furthermore, assume that there exists ...
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0answers
76 views

Filter/Removal of periodic 'delta-peaks'

Currently I am measuring data (Counts over Time). Due to measurement problems I have some nasty peaks in this data. These peaks are periodical, very sharp (~3 datapoints over a range of 10000) and ...
2
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1answer
93 views

What's the best function to use to fit this data?

{7502, 6610, 4988, 2861, 2242, 1746, 1433, 1312, 949, 793, 767, 664, 660, 653, 588, 578, 575, 572, 553, 500, 445, 418, 374, 165, 108} I was looking at the number of seeds for torrent files for ...
0
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1answer
47 views

arctic sea ice data by year

I want to demonstrate the usefulness of regression lines to my class, and I was hoping to do so with some data about the Arctic sea ice. What I'd like is the maximal area covered by the ice per year, ...
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1answer
61 views

Variable frequency redistribution

I know that there is a way to "redistribute of the frequencies of a variable" as stated here: Dorian Pyle book chapter 7 section 2 paragraph 3 (7.2.3): The easiest way to adjust distribution ...