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.
Questions tagged [data-analysis]
1056 questions
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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 average from $\Delta r$ to $2\Delta r$ and so on.
In…
jorgen
- 916
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Reducing big amount of data into smaller
I have a sensor that can make thousands of measurements per second, it sends all this measurements ( packed in a single message ) using a messaging protocol over internet to my service, there I need to translate all the data ( it comes in form of…
Bruno Cerk
- 111
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Guessing a functional form to use for fitting an exponentially decaying spectrum with peaks
I'm trying to fit an experimental spectrum (Intensity vs frequency) in which the intensity exponentially decays as frequency increases. However, there are peaks amidst the exponentially decaying background.
To fit this spectrum, what type of…
LooseyGoose
- 11
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1 answer
Training vs validation set
I have a data set with which I am trying to find correlations.
I split the data into a training set and a validation set. I also have a solver I built which finds the "best coefficients" to give me the best results on the training set.
After…
Frank
- 880
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1 answer
Based on the coinmarket cap api, how do they calculate the bitcoin percent change
I know this isn't the correct stack exchange site for this question but this question has to do with math and creating a formula.
I am trying to figure out how coinmarketcap calculates the bitcoin percent change for other coins. For example on…
cup_of
- 113
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How to measure distribution of high-dimensional data
I have to methods of projecting random samples in $R^n$ onto a manifold defined by $C(q)=0$, which is a lower-dimensional subset. Now, samples in $R^n$ are uniformly distributed. However, when projecting on to the manifold, the distribution is not…
Jeremy Span
- 19
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What is the difference between internal and external studentized residuals?
I am trying to understand the difference between them and what happens if they are same and different for a specific observation?
daultongray8
- 167
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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 for each $1\leq i\leq n$ a set of non-negative…
Frederik Ziebell
- 131
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1 answer
Given two growth rates, do I have enough information to calculate the third?
A manager is reporting results for investors. There are two components that make up his business division: Part($A$)+Part($B$)=Whole($C$), or $A+B=C$.
The manager doesn't want investors to know precisely how large $A$ or $B$ are, for competitive…
Phooj
- 11
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1 answer
Data Processing: Excel vs Desmos Discrepancy
I have the following set of data:
Plotting this on Excel gave me a nice, smooth curve:
With the Polynomial Regression function, I get a 5th order polynomial that fits very well:
The issue arises when I transfer both the data values and the best…
StopReadingThisUsername
- 1,553
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Is there a tool for finding invariant features on data?
I don't know how to make a specific question, because that's what I don't know and I'm asking for.
I don't even know what tags should I put on this question. If I knew, I would have the answer.
I have a set of 2D data (images), and I want to find…
Lilo Pasnik
- 11
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1 answer
Equal interval data classification technique formula confusion
The formula for breaking a sequence of values into groups of equal ranges is:
max - min / number of categories
I would like to know why is it necessary to subtract the maximum value from the minimum value?
Thanks
Imran Azad
- 113
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1 answer
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 point is maximized
The sum of the x values of each…
user3144349
- 11
1
vote
1 answer
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 have an item whose value can range across a large…
Mred
- 11
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3 answers
'Squashing' a graph of data?
I have a vector of sample data that describes a divergent oscillation like in this image.
I want to transform this data (just the data, not the system or anything), so that the data does converge to zero. I also want to keep the peaks of data at…
Projectile Fish
- 383