Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [procrustes-analysis]

A form of shape analysis where one set of points is rotated in some way to try to superimpose it over another set of points to achieve maximal overlay fit.

31 questions
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Similarity measures between curves?

I would like to compute the measure of similarity between two ordered sets of points---the ones under User compared with the ones under Teacher: The points are curves in 3D space, but I was thinking that the problem is simplified if I plotted them…
Alex
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Find the rotation between set of points

I have two sets (sourc and target) of points (x,y) that I would like to align. What I did so far is: find the centroid of each set of points use the difference between the centroids translations the point in x and y What I would like is to find…
Wiliam
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Factor analysis on multiply imputed data

I have a data set with approximately 500 observations on eight key variables. There are a lot of missing data; only about 1/12 of the observations are complete. I am using PROC MI and MIANALYZE in SAS to run various regressions on multiply imputed…
Peter Flom
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Looking for a test for shape comparison

I have two different time series both length = 100 and I need to know what is the best test (non-parametric, if possible), that return how much these two series are same or similar shapes. Here are two examples: first one the two series are very…
Alberto acepsut
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Derivation of Procrustes transformation

I'm curious about the derivation for the Procrustes transformation. I'm following ESLII: see figure 14.25 and problem 14.8 (Procrustes distance with scaling). Given matrices $\mathbf{X}_1$ and $\mathbf{X}_2$, both $n$-by-$p$, the problem…
Adrian
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Find a matrix with orthonormal columns with minimal Frobenius distance to a given matrix

Let $\mathbf A$ be an arbitrary $n \times m$ matrix with $n \ge m$. I want to find $\mathbf X$ of the same size with orthonormal columns that minimizes the Frobenius norm of the difference between $\mathbf X$ and $\mathbf A$: $$\arg\min \|\mathbf…
amoeba
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Finding optimal correspondences between objects given two square distance matrices

I would like to find the optimal correspondences between two systems of objects based on the distances between objects WITHIN the two systems. So, the input to the algorithm would be two square distance matrices which express the distances of every…
Rob Goldstone
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Is factor analysis appropriate for repertory grid data?

I've used factor analysis for questionnaires and such before, but I have a new research question now and it doesn't seem like anything similar has been done. I've had participants rate 8 news articles on a variety of measures. However, each measure…
Adb
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How to reduce the number of variables in cluster analysis?

I've got 10 (yes, only 10) cases over 1000 variables (e.g. measurements of concentrations of 1000 different compounds at 10 different time points). I can group these cases into 3 clusters in 1000-dimensional space (complete linkage, cluster sizes 3,…
dan
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Ways to modify data minimally while the variables to follow the desired covariances

Let $\bf X$ be the p-variate dataset. I want to modify the data to p-variate data $\bf Y$ so that its variables satisfy precisely a given SSCP (or covariance, or correlation) matrix $\bf R$: $\bf Y'Y=R$, and the requirement is that the modification…
ttnphns
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Multivariate Analysis of Ecological Data: Procrustes analyses or GLM?

I have a dataset containing 6 variables (vegetation cover in percent) and the number of species found in 30 areas. I would like to test if the different vegetation covers explain species richness. Question: What kind of statistical approach is…
GoldFire
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Compare Procrustes values

I have two sets of spatial data which underwent a transformation. I'd like to compare the effect of the transformation on two sets of data to test the hypothesis that the transformation had a larger effect on one set of data. I planned to use a…
Justine
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Multiple linear regression through orthogonal matrices

An example of linear regression could look like: $min \sum_{i=0}^{m}||x_i A - y_i||_2^{2}$, where ${x_i, y_i} \in \mathbb{R}^n$ and $A \in \mathbb{R}^{n\times n}$. I am interested in knowing how do I solve such problem with an of the following extra…
aboSamoor
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how to calculate observation within and between groups variances of PCA scores

I'm kind of new here, and also not a professional statistics guy, so sorry if the answer is obvious and I'm missing something, but I looked everywhere and couldn't figure it out. I'm doing geometric morphometrics on 52 lithic artifacts. All the…
G. Herzlinger
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Comparing facial curvature of two human faces

I need help determining if what I'm doing is sufficient. I have extracted the "curvature" from two human faces (essentially the curve that goes from one ear, down the face to the chin, and back up to the other ear). Now I want to compute a curve…
user2974849
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