Regression analysis is the process of measuring and establishing a relationship between a dependent variable and one or more independent variables.
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52 views
Fitting one set of points to another by a rigid motion
I'm not really sure how to explain this problem clearly, so please bear with me.
I have a basis of 3 orthonormal unit vectors and a position, a standard 4x4 transform matrix in computer graphics.
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0answers
25 views
Fitting a logistic regression using lassoglm in matlab
I am fitting a logistic regression model using lassoglm in matlab. I issued the following command
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3
votes
1answer
33 views
How to obtain the minimum set of variables required in a model to produce accurate estimation?
I have a system which I assume is linear. I have a matrix $A$ of which each row is a coefficient of a unknown variables in vector $x$. I have vector $B$ which contains the result of each $Ax$.
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3answers
101 views
Averaging scattered data
I have multiple sets of measured data that can easily be visualized using a scatter plot (red and black points in the figure). If my measurements were perfect, the red and black points should lie on a ...
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4answers
165 views
parameters estimation
I have to estimate a parameter (K), but I don't know how I can do it. I think by a regression model (minimum least square?), but I'm not sure. The system is:
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0answers
46 views
Determining optimal number of clusters and Davies–Bouldin Index?
I'm trying to evaluate what is the right number of cluster needed for clusterize some data.
I know that this is possible using Davies–Bouldin Index (DBI).
To using DBI you have to compute it for any ...
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votes
2answers
182 views
How to compute the optimal ridge regression model
I found R function ridge.cv very useful.
I would like to implement the equivalent function in MATLAB. As a starting point, I used MATLAB function ...
3
votes
2answers
99 views
When fitting a Gaussian-like function, how does the amount of baseline datapoints affect the fit?
I am fitting a curve to some instrument data. The data is a pulse with a particular functional form, which starts from and returns to a constant (with noise) baseline level before and after the pulse.
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votes
2answers
94 views
Matching Similar Items from a Set
I'm trying to match items. Given a set of $n$ items I can rank on a scale from 0 to 100 of how similar they are to one another. For instance, if item $n_1$ is milk and item $n_2$ is also milk, then ...
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2answers
401 views
Reporting curve-fit results in a scientific paper
(I hope this question fits this site; if not, accept my apologies).
I ran a certain simulation, and got a time series y(t), t = 0, 1, ... 20. After trying some functions, I found that:
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votes
1answer
131 views
Recover curves from noisy collection of points
Background: I'm trying to make a system that tracks a number of bubbles in a video
I'm implementing the bubble detection in the single image case using the Circular Hough Transform. Due to ...
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votes
2answers
139 views
Linear regression with quadratic constraints
What methods are suggested to solve problems of the form $\min || {A} x - y ||_k$, subject to $x^T P x \leq c$, and/or $x^T Q x = d$?
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votes
2answers
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What are all of the different methods for parameterizing an amino acid (or other small molecule)?
What are all of the different ways to derive the partial charges, van der Waals interactions, bond lengths, etc. of an amino acid (in other words, all of the parameters that could be used in a ...
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1answer
132 views
Polynomial Regression using Semidefinite Programming
I'm trying to design the frequency response function for a low-pass filter. I need the function to be polynomial and to fulfill the following constraints: the coefficients must sum to 1, the function ...
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votes
1answer
186 views
Fitting a grid to an STM image
Suppose I have a scan from an STM image (very much like the things you see here). Suppose I have a simple square lattice with lattice parameter a.
What I'd like to do is to numerically find the ...
7
votes
2answers
211 views
Kolmogorov–Smirnov test for multivariate data
I have a set of files consisting of randomly selected points from a dataset, each file belonging to a particular class. Each row in these files contains the coordinates in n-space of the point. I'd ...
4
votes
2answers
177 views
best way to optimize a function with linear/non-linear parameters
I am trying to fit some raw data using a function of the form
$f(r) = \sum_{i=1}^{K} d_kS_k(n_k,\alpha_k,r)$
where
$S_k(n_k,\alpha_k,r) = \frac{\alpha_k ^{n_k+3}}{(n_k+2)!}r^{n_k}\exp(-\alpha_kr)$
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votes
3answers
244 views
what should be the criteria for accepting/rejecting singular values?
I am solving a system using singular value decomposition. The singular values (before scaling) are:
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2answers
225 views
Quickly finding rough lines in sets of points
In a particular class of detector our data comes out as pairs of points in two dimensions, and we want to string these points into lines.
The data is noisy, and is binned in one direction but not in ...
3
votes
2answers
263 views
Linear regression via SVD not producing best fit with escalating polynomial degree
I am using a basic singular value decomposition (via LAPACK) routine in FORTRAN to solve an overdetermined system in the form of $A\cdot X = B$ where $\mathrm{size}(A) = [m,n]$ with $m > n$.
My ...
