Questions tagged [algorithms]
An unambiguous list of computational steps involved in finding a solution to a class of problems.
947
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Spatial Temporal Clustering evenly spaced over time
I have a large dataset of spatio-temporal data. It has longitude and latitude coordinates, and a date for each observation. For example:
Long
Lat
Date
50
20.43
9-19-2010
51
19.5
10-4-2010
51
19.3
...
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Ask a coding problem for the equivalence of unconstrained Optimization with L1 Regularization [duplicate]
I recently read a statistics paper. It has an unconstrained problem:
$$\min_\theta F(\theta)+\lambda || \theta||_1$$, where $$F(\theta)=L(\theta)+\frac{\rho}{2}|h(W(\theta))|^2+ \alpha h(W(\theta))$$
$...
- 21
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How to guess a random walk to achieve max sample correlation?
Define this 1-D discrete random walk start from 0: roll a die (the die may or may not be fair, the fixed probability of each face is unknown to the observer/guessor)...
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Why does R robustbase and rrcov covMcd compute reweighted step trimming adjustment with actual fraction of outliers?
covMcd and CovMcd in R robustbase and rrcov compute by default a reweighting step.
Reweighting in MCD and similar computes the Mahalanobis distances and the uses a cutoff using the chisquare ...
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Probability algorithm on strings
Let $x$ be any binary string $\in (0,1)^*.$
The majority language is given by:
$$\text{MAJ}:=\{x\in (0,1)^*:\sum_{i=1}^ {|x|}x_i>\frac{|x|}{2}\},\text{where $x_i$ is the $i$-th position value(...
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fuzzy decission making
I'm working on decision-making using Double Hierarchy Fuzzy Linguistic terms. I want to ask if can we compare two Double Hierarchy Fuzzy Linguistic terms.
I am trying to implement the TODIM algorithm ...
2
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1
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Detecting a single change point within an interval with a certain probability
I have a dataset $D$ of binary values, with length $|D|$. There is some unknown $d \in \left[1,2,\ldots,|D|\right]$ (usually, $d$ will be somewhere in the middle) such that, for any $i<d$, $D_i$ ...
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28
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Statistical methods for comparing performance of ML algorithms on unevenly distributed datasets
Having multiple ML algorithms for outlier/anomaly detection and even more datasets with always two classes (which are intentionally distributed unevenly), I did cross-validation tests for each model ...
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2
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Is R's weighted sample without replacement function misleading?
Background
The 2023 article "Remarks on some misconceptions about unequal probability sampling without replacement" by Tillé suggests the sample function ...
- 582
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Sample size in simulation and stopping criteria
I want to estimate the average of a random variable by simulation. Also, I want to estimate a proportion by simulation.
I know that there are formulas to calculate the minimum sample size so that the ...
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How to create a scoring algorithm based on the interactions of two trends?
I have two variables represented as a time-series with monthly observations. I am attempting to create a scoring system -1 to 1 where: 1 represents a strong shift in trend from B to A and -1 ...
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49
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How to shuffle and deal with constraints?
I'm playing a 4-player game of cards. My opponents are called A, B and C. At the beginning of the game, each player has been dealt a hand of cards out of a deck containing 4 suits of cards: Black, Red,...
- 21
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Can you penalize based on difference between training and testing error?
Is it a valid or useful technique to penalize the model based on the objective function + abs(training error - testing error). The error would probably have to be scaled. This seems useful, and I am ...
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Methods for delaying the "break" in non-linear least squares optimisation when the step size gets too small?
I am using the Levenberg-Marquardt method for calibration purposes. Typically, the RMSE of my calibration looks like:
I want to break the algorithm when the algorithm step-updates start to slow down, ...
2
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What algorithm can find a gradient increase using the maximum value of small circles on a two dimensional plot?
I'm looking to make research on an algorithm that finds the maximum increase (gradient) on a 2D-landscape using the maximum values found on circles.
The algorithm looks at the values on each circle to ...
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