Ltrinv

This function is the inverse function of <code>Ltrans</code>, which is to map a vector back to a symmetric matrix.

To decompose symmetric matrices such as brain connectivity matrices so that one can extract sparse latent component matrices and also estimate mixing coefficients, a blind source separation (BSS) method named LOCUS was proposed in Wang and Guo (2023) <arXiv:2008.08915>. For brain connectivity matrices, the outputs correspond to sparse latent connectivity traits and individual-level trait loadings.

Jialu Ran

LOCUS

Low-Rank Decomposition of Brain Connectivity Matrices with
Uniform Sparsity

Yikai Wang

Ying Guo

Ltrinv function

<dl> <dt>x</dt>
<dd>A vector to convert to a matrix, which is of length p.</dd> <dt>V</dt>
<dd>Dimension of the matrix which <code>x</code> is converted to.</dd> <dt>d</dt>
<dd>Whether diagonal is kept in <code>x</code> or not.</dd></dl>

Arguments

Inverse function of Ltrans to map back a vector into a symmetric matrix. — Ltrinv

<dl>

 <dt>x</dt>
<dd>A vector to convert to a matrix, which is of length p.</dd>

 <dt>V</dt>
<dd>Dimension of the matrix which <code>x</code> is converted to.</dd>

 <dt>d</dt>
<dd>Whether diagonal is kept in <code>x</code> or not.</dd>

</dl>

Ltrinv: Inverse function of `Ltrans` to map back a vector into a symmetric matrix.

Description

Usage

Value

Arguments