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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2
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3answers
90 views

$4\log_2(n)=n$ How to Solve for $n$?

As the title suggests, my log skills are pretty lacking. Need to learn how to get from $4\log_2(n)=n$ to $n=16$ ($\log$ base $2$). I've searched Google and it seems I am missing some core concept ...
0
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1answer
40 views

Decision to market one or the other game, based on the expected demand

For example, there is a new video game to market, lets call it Game 1, and there is a 0.60 probability that its competitor will produce a new game similar to it. (This 0.60 may not need to be known ...
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0answers
61 views

Root mean square error from dataset with different time interval

I have two data sets. The Data-set I, contain 2 columns. (field observation data) Column A is the time series with 30 minutes duration. Column B is the value. The Data-set II, contain 2 columns. ...
1
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0answers
37 views

Approximating a probability distribution given multiple datasets

I am beginner in mathematics/statistics and apologise in advance for my faulty use of language. I am working on a problem in statistical genetics. Given a dataset, $D$, I obtained probabilities for ...
1
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0answers
18 views

Correct sampling methods for this data set / requirements

I am just looking for a push in the right direction as to what kind of sampling methods I can use to fulfill this set of sampling criteria. I had thought stratified sampling, but I'm not sure if ...
0
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4answers
53 views

Finding function for data

I'm in need of a function for this data which occurs in an application I am making. I've been staring at it for hours and I can't figure it out, hope someone here can help me. Here's the data: f(x) = ...
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1answer
50 views
0
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1answer
38 views

GPS Data Doesn't Make Sense — Some type of GPS shift or transformation in place? — NOAA Weather Data [closed]

I had a hard time trying to figure out which of the Stack Exchange subsections that this question would correspond to, so if it doesn't seem relevant on this board, please let me know and I'll take it ...
2
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1answer
23 views

Aproximate data with this equation (or linearize the equation)

I have found an equation that describes the behaviour of a phisical system: $$ y=a_1e^{-a_2x} + a_3 + a_4x + a_5e^{{-a_6} / {(1-x)}}$$ Now I have data of that physical system and I want to ...
1
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0answers
35 views

Data Envelopment Analysis

I have been given an example for a Linear Programming Model in Data Envelopment Analysis. The given data is (the last two columns are the ratios but so far I've only used them in a graphical method); ...
0
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0answers
25 views

Fitting discrete distribution (negative binomial) for early data values

I'm having some difficulties with fitting a discrete distribution function (I'm specifically using the negative binomial distribution). Here's my setting: I have a source of incoming items, each with ...
0
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4answers
133 views

Predicting the movement of people on a grid.

Let there be a $30$ by $30$ grid that is there are $900$ tiles.The rows are numbered from 1-30 while the columns are numbered from (i) to (xxx). There are total of $100$ people and each of them is ...
1
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3answers
41 views

Separating populations and estimating line-fit parameters

Given a dataset containing two populations, each of which can be described by a linear relationship between two variables in each sample with high R$^2$, how does one separate the two populations (and ...
1
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2answers
65 views

Can we express “exactly X” with set theory?

I have a question that I think that is a better fit here than a programming SE as SQL is founded on set theory and my question is more about set theory than about a programming question. Assuming I ...
1
vote
2answers
45 views

Scaling data into $[-1,1]$

I have a data in the matrix for: \begin{bmatrix} 1 & 2 & 3 & 9 & 6\\ 8 & 2 & 7 & 4 & 6 \\ 1 & 2 & 8 & 7 & 4 \end{bmatrix} Each row corresponds ...
1
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2answers
42 views

Best way to generalize a distribution of data into smaller subsets?

Suppose I had a data set as follows: 168.95, 176.83, 178.13, 179.61, 179.44, 172.83, 173.37, 174.06, 174.94, 175.43, 175.73, 175.5, 173.78, 174.06, 172.71, 174.3, 178.38, 178.43, 177.18, 175.34, ...
0
votes
2answers
93 views

Function to fit a curve

I am trying to fit a function to data that looks like the following. I have no idea what the function is, but by visual inspection it seems to be a parabola (or some other convex polynomial) + a ...
1
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0answers
46 views

Why do candlestick plots seem to show a cyclical structure?

One oddity I notice is that if a random or quasi-random data series such as price data is plotted, it is similar to a random walk, but if the same data series is plotted using candlesticks ...
-1
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1answer
125 views

How do you set the range for ListPlot (mathematica)

I have a large set (about 2050 values) of data that I would like to make a graph out of. The data is in two columns in Excel. I copied the first column and made the list x={0, 3.6, 7.1, 10.7...} and ...
3
votes
1answer
52 views

The number of nuts in a package of “Premium Cashews” is normally distributed with a mean of 433 and a standard deviation of 6 nuts.

The number of nuts in a package of "Premium Cashews" is normally distributed with a mean of 433 and a standard deviation of 6 nuts. Packages with fewer than 420 nuts or more than 445 nuts will be ...
1
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1answer
25 views

Continuity correction: Change P(2 ≤ x < 9) to continuous?

Convert discrete probability into continuous probability using continuous correction: attempt: Discrete: P(2 ≤ x < 9) therefore continuous should be Continuous: P(1.5 < X < 8.5) Is this ...
1
vote
1answer
21 views

Rating based on 2 criterias

I'm trying to write rating system which scores items based on two criteria with different importance. Criteria_1 will have importance 0.2 and Criteria_2 will have 0.8. Maybe a bit of trickiness adds ...
0
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0answers
14 views

Computing a threshold value for paired data

I have a dataset of vector pairs; for each pair ($x_1$, $x_2$) I have two values $V$($x_1$,$x_2$) and $U$($x_1$,$x_2$) (two metrics). I also know a threshold value $U^*$ such that any pair ($x,y$) ...
3
votes
1answer
224 views

How do I 'reverse engineer' the standard deviation?

My problem is fairly concrete and direct. My company loves to do major business decisions based on many reports available on the media. These reports relates how our products are fairing in ...
0
votes
1answer
15 views

How do I calculate the function of an (expected) logarithmic distribution, if I know the area under the curve & one data point?

I'm trying to get the function that lets me determine the value of y, where x is an arbitrary number. In this case, I'm looking at sales charts, and I'm making the assumption that the function is ...
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0answers
12 views

Likelihood function of truncated data

I am having a little trouble understanding the concept and derivation of the likelihood of truncated data. For example, if I want to find the likelihood function based on a sample from a ...
1
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0answers
67 views

Significance Tests & Confidence Intervals for Non-normal data

I have 2 nonnormally distributed samples of different sizes (N1~=N2). To evaluate whether there is a significant difference between these samples, I used the Mann_whitney U test (ranksum in MATLAB) ...
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0answers
23 views

“Sane” quantisation of moderate-dimensional analogue data

Warm-up problem (with solution): Suppose I have a measuring device that spits out a stream of real numbers, which I will model as i.i.d. random variables with range $\mathbb{R}$ and continuous ...
0
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1answer
49 views

Large Regression dataset

For a project I need a large regression (least squares) dataset: If $n$ is the number of samples and $p$ the number of features, then I need $p < n$ and $p,n$ both very large. For example ...
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2answers
77 views

Determining function from simple xy graph

I'm not sure if this question is too vague for here. Will delete if necessary. I have a set of points, (1,782), (2,893), (3,992),... and I'm trying to determine the function that was used to generate ...
0
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0answers
20 views

Average data output from randomized data input?

Apologies about the title, I am not sure exactly how to word it. Currently I am receiving data from a Bluetooth Low Energy peripheral (RSSI in dB). Even if both the receiving device and the ...
1
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1answer
67 views

Weird formula for linear regression

I'll try to make the matter as clear as possible given the circumstances. My boss asked me to look at an old report a former employee wrote around a couple of months ago. Apparently the report ...
1
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1answer
27 views

Non-close-form Regression Research

As I try to process some physic experiment data that I don't have the closed form formula with unknown parameters, I have to use some regression models like polynomials or normal distributions . The ...
0
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1answer
99 views

Hypothesis Testing, simple against composite.

i've got some trouble understanding this exercise from Amemiya's Introduction to statistics: Given the density $f(x) = \frac{1}{\theta}$ from $0 < x < \theta$, and 0 elsewhere, we are to test ...
0
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1answer
328 views

Comparing annualised volatility from monthly and annual data

I fear there is a very simple answer to this question and its killing me that I can't see it. I am interested in calculating historical volatility: I have monthly index values starting in Jan 2005 ...
0
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0answers
14 views

In classification algorithms what is the idea behing choosing the first n values?

I came across the cluster pruning algorithm the other day. The algorithm first chooses √N random leaders for N points and after that assigns the new points to the nearest leaders. What is the idea ...
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0answers
13 views

Isolating clusters in data

This is a problem that I keep encountering in one form or another every so often. Given a large N dimension space with a sufficiently large (M) sample of points. [1] If I were to be asked to find a ...
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0answers
7 views

grouping of skewed dara

I have a set of data composed of the measurements of spaces. There are 2 distinct sizes represented in this data set. (distinct in that the larger size is larger by some unknown multiple) I am ...
1
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1answer
139 views

Mathematical model building with dependent and independent variables

I have been working with data and building models on data. I have developed models in regression using cubic and power series. It works fine for variables with one dependent and one independent ...
0
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1answer
30 views

Rescaling Dataset by a constant value

I have two sets of measurements that measure one thing. I would like to graph the relative heights of the measurements, however one set is nearly consistently higher than the other one. I would like ...
0
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1answer
48 views

Experimental Data Analysis

Suppose I have performed 2 different experiments to measure the number of cell in a mice. In the first experiment, we measure the cell in odd day (day 5,7,9,11,13) and in the second, we measure the ...
1
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0answers
21 views

mutual information for power low distributed data?

I have a dataset with power-low distribution, I would like to measure some kind of correlation/mutual information between the data to its class,(for feature selection task), Can I use ...
2
votes
0answers
157 views

curve fit but unknown function

I face a strange problem. I have data $[X,Y]$ with no noise. If I plot $Y$ as a function of $X$, it looks like a straight line and the regression coefficient is quite good. For the simplest model ...
1
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1answer
80 views

Can you please help me model this curve?

I have no idea how to model this curve. Can someone please help?
0
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2answers
163 views

A simple GRE data-analysis question - but I dont know what it is asking

It is a GRE data analysis question. I don't if I am dumb in Math, or in English. But I could not understand what is the question a want me to answer. Please give me a hint.
0
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1answer
89 views

compering distances between points in different dimension

I have pairs of points, each pair is in the same dimension, and I need to measure the distance between each pair: For example: ...
1
vote
1answer
56 views

Given two arrays, how can one determine the the intersection?

I have two datasets (A & B). They each have 1000 numbers. 99% of the time: A < x <= B However, 1% of the time B < x < A. How can I solve for x, ...
0
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0answers
41 views

How to search for an object in more efficient way?

I have a doubt how to check if structure contains an object. Simple sketch of my structure: Root - is a group which can contain groups, keys, values. Group - can contain groups keys, values. Key - ...
4
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2answers
175 views

Detecting increasing pulse trains

I have a one dimensional point process representing the times of events which is also mixed in with lots of data that I regard as noise. The interval between the events in the point process are ...
0
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1answer
44 views

Type of Distribution for Survey Answers 1 to 10

I'm investigating survey data where participants are asked to answer based on a scale of 1 to 10 typically, the average is around 8.5 with most responses between 7-10, with a lower numbers like 3 ...