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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calculate optimum point in a list
Hello guys so I have a list of around 1000 items, and each item has the following properties:
price (euros)
points (number)
I can have 20 items in a set, and have a budget of 1000 euros.
I want to find the optimum item list so that I have the most…
mdb29136
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Error Vector Magnitude: Ref at Origin
I have a cluster generated by white Gaussian noise in terms of a phase and an amplitude. The center is at the origin and I want to calculate the Error Vector Magnitude of this cluster (equation below).
1) The problem I ran into was that the…
CLDuser2.-
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Growth in forward difference
I am looking at a pattern in some data, and I am trying to figure out if it tells me anything about the underlying structure of the dataset, or if this is just an obvious algebraic relationship I am missing.
The explicit relationship between…
wglass21
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Mean, Variance, Standard Variation
I submitted this question the other week to my tutor, but it was wrong. the only thing correct was the mean. He did not tell me why it was wrong or the correct answers.
Can anybody tell me why this is wrong please? And where I went wrong?
Question…
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Calculating an average of multiple data sets based on priority.
First and foremost I'm no mathematician, it may be a case of over complication.
What I'm trying to do is that I have 2 sets of data, I want to calculate one average for both sets but I want the first set to have more 'influence' over the average…
Faraday
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1 answer
noisy 1-second GPS data
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 makes. Due to accuracy issues, if I capture this GPS…
Michael
- 17
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The best choice of fitting function for the data
I got a set of data points shown in the following figure:
I need to fit this dataset to interpolate and extrapolate some new data points. What is the best choice of the fitting function for this set?
Lonitch
- 129
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1 answer
How to tell if samples are dependent or independent?
Let's say we have some data from 200 diamonds.100 of them are blue and 100 of them are red. We also have the corresponding price for each diamond. Now we divide our data into two samples, with respect to each colour. Would you say that these two…
Sr52
- 137
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How to shift the baseline of an IR spectra
I have the fellowing IR spectra (red curve) of a sample that contains TiO2 and I would like to change the baseline in order to have a straight stable one (like the green spectra).
I wonder if its changes the other information of the spectra or not.…
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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 normalization and how can I do that in Matlab?
Mohammad Ali Akbari
- 113
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sensitivity-analysis for an optimization problem
I performed an optimization for a formula with 3 inputs and 5 outputs. But I want to perform a sensitivity analysis.
I have two questions:
1-I want to know that what is the sensitivity analysis and what is its formulation.
2- Is it related to the…
Nima
- 25
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Solving for unkown ratios while being given various sums of the unkowns
Setup/Scenario:
So let's suppose you have 4 types of apples:
red, blue, yellow, and green
When present, each color apple will always be present in a proportionally consistent manner to other colored apples. Different apples will appear in different…
Estif
- 5
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1 answer
detect when a line crosses a curve more than 2 times
I have a set of plotted X,Y data points making a curve as shown below in the black line. What i need to do is draw a line from each of the X,Y s to all of the other XYs to determine the one with the highest slope for each point.
any line that…
R.Merritt
- 101
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Obtaining the most informative subset of data
I'm not sure if it's the best place to ask this, as it's completely layman problem, but here we go. I've got a 2D data matrix, with var 1(lets call it rows) and var 2 (columns) and binary values only, where 1's count as valuable and 0's not really.…
kopiks
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1 answer
Zero-width histogram bin?
I want to plot a histogram of some timing data. The timing data, represented by a continuous variable t, is binned as follows:
t=0
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John Wickerson
- 431