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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1answer
13k views

Boxplots and bar graphs

I'm studying for the GRE and came across several questions that I was unable to answer in a practice booklet, even after looking at the answer and trying to work backwards, and searching google and ...
11
votes
4answers
4k views

Polynomial fitting where polynomial must be monotonically increasing

Given a set of monotonically increasing data points (in 2D), I want to fit a polynomial to the data which is monotonically increasing over the domain of the data. If the highest x value is 100, I don'...
2
votes
1answer
55 views

Optimize database indexes, the sequel

Background For those not familiar with databases. Indices help to speed up database searches, but they come at the cost of memory. Since you like your database to be fast, they are best cached in RAM ...
2
votes
1answer
274 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, x_3,\...
2
votes
3answers
129 views

Finding similarity between elements using statistics

I have a dataset of DJs in which I'm trying to find DJs similar to a specific DJ. Each DJ has a set of a genres with a certain percentage. How can I find the similarity between 2 DJs? The following is ...
1
vote
3answers
991 views

Find parameters for exponential function fitting to datapoints

I have a set of datapoints, in this case the temperature of an object adjusting to the environment temperature over time. Because I know these kind of processes take the form of $$f(x)=Ae^{x/B}+C$$ I ...
1
vote
2answers
79 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 ...
0
votes
2answers
57 views

Optimize database indexes

Q: I have 14 columns, how many indexes do i need to create to cover all possibilities? Examples of possibilities: col1 col12 col5, col3, col4 col7, col2, col12, col1 all 14 columns -- Order can ...
0
votes
1answer
57 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
votes
0answers
21 views

Is the sum of all cross-correlation samples representative of target existence likelihood?

Answers to this question take the peak in the cross correlation as the measure to the likelihood of the trigger signal exist in the received signal - this is pretty much text book. My question is ...