A scree plot for choosing the number of factors. The y-axis shows the standardized singular valuesˆσvaluesˆ valuesˆσ k / √ N J, wherê σ k s are obtained from Step 7 of Algorithm 1. The data are simulated from an IFA model with K = 5, J = 200, and N = 4000. The input dimension is set to be 10 in Algorithm 1. A singular value gap can be found between the 5th and 6th singular values

A scree plot for choosing the number of factors. The y-axis shows the standardized singular valuesˆσvaluesˆ valuesˆσ k / √ N J, wherê σ k s are obtained from Step 7 of Algorithm 1. The data are simulated from an IFA model with K = 5, J = 200, and N = 4000. The input dimension is set to be 10 in Algorithm 1. A singular value gap can be found between the 5th and 6th singular values

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We revisit a singular value decomposition (SVD) algorithm given in Chen et al. (Psychometrika 84:124–146, 2019b) for exploratory item factor analysis (IFA). This algorithm estimates a multidimensional IFA model by SVD and was used to obtain a starting point for joint maximum likelihood estimation in Chen et al. (2019b). Thanks to the analytic and c...

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... first run Algorithm 1, but replace the unknown K in Step 1 of the algorithm by a reasonably large number K † . Then, a scree plot can be obtained by plottingˆσplottingˆ plottingˆσ k in a descending order, forˆσforˆ forˆσ k s produced by Step 7 of Algorithm 1. Figure 1 shows such a scree plot, for which the data are generated from a five-factor model (K = 5) with J = 200 and N = 4000, and the input number of factors is set to be K † = 10 in Step 1 of the algorithm. Unsurprisingly, an obvious gap is observed betweenˆσbetweenˆ betweenˆσ 5 andˆσandˆ andˆσ 6 . ...
Context 2
... first run Algorithm 1, but replace the unknown K in Step 1 of the algorithm by a reasonably large number K † . Then, a scree plot can be obtained by plottingˆσplottingˆ plottingˆσ k in a descending order, forˆσforˆ forˆσ k s produced by Step 7 of Algorithm 1. Figure 1 shows such a scree plot, for which the data are generated from a five-factor model (K = 5) with J = 200 and N = 4000, and the input number of factors is set to be K † = 10 in Step 1 of the algorithm. Unsurprisingly, an obvious gap is observed betweenˆσbetweenˆ betweenˆσ 5 andˆσandˆ andˆσ 6 . ...

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... In particular, variants of the Lanczos Algorithm (whose convergence also depends on gaps of subsequent singular values σ k+1 − σ k ) are found in standard numerical linear algebra programs in MATLAB, Mathematica, Scipy (python), and others through their dependency on Fortran's ARPACK library [24]. In particular, these methods and other variants are found in various implementations of principal component analysis (PCA) and singular value decomposition (SVD) algorithms [34,52], as well as neural network architectures and computations [26,36]. Power iteration also appears in recommendation engines from Twitter (X) and Google Search [16,20]. ...
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