
The covariance matrix is one of the most important elements of probability calculation, it is a symmetric, positive-definite matrix. The question of how to approximate well has been raised many times. A solution to this problem is answered in this article. Symmetric, positive-definite matrices can be approximated by symmetric block partitioned matrices with structured off-diagonal blocks.
covariance matrix, entropy loss function, Measures of association (correlation, canonical correlation, etc.), block covariance structure, Estimation in multivariate analysis, Special matrices, approximation
covariance matrix, entropy loss function, Measures of association (correlation, canonical correlation, etc.), block covariance structure, Estimation in multivariate analysis, Special matrices, approximation
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 4 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
