Correction: Diagnosis of cardiac abnormalities based on phonocardiogram using a novel fuzzy matching feature extraction method

Correction: Yang et al. BMC Medical Informatics and Decision Making (2022) 22:230

https://doi.org/10.1186/s12911-022-01976-6

After the publication of the original article [1], the authors reported an error in Eq. 1, which reads:

$$(x_{1} {\mathbf{;}}x_{2} {\mathbf{;}} \ldots {\mathbf{;}}x_{n} ) = \left( {\begin{array}{*{20}c} {x_{11} } & {{\varvec{x}}_{12} } & {\ldots } & {{\varvec{x}}_{1n} } \\ {{\varvec{x}}_{21} } & {{\varvec{x}}_{22} } & {\ldots } & {{\varvec{x}}_{2n} } \\ \vdots & \vdots & {} & \vdots \\ {{\varvec{x}}_{n1} } & {{\varvec{x}}_{n2} } & {\ldots } & {{\varvec{x}}_{n3} } \\ \end{array} } \right)$$

Xn3 in the equation is incorrect as it should have been Xnn. Equation 1 should have been written as follows:

$$(x_{1} {\mathbf{;}}x_{2} {\mathbf{;}} \ldots {\mathbf{;}}x_{n} ) = \left( {\begin{array}{*{20}c} {x_{11} } & {{\varvec{x}}_{12} } & {\ldots } & {{\varvec{x}}_{1n} } \\ {{\varvec{x}}_{21} } & {{\varvec{x}}_{22} } & {\ldots } & {{\varvec{x}}_{2n} } \\ \vdots & \vdots & {} & \vdots \\ {{\varvec{x}}_{n1} } & {{\varvec{x}}_{n2} } & {\ldots } & {{\varvec{x}}_{nn} } \\ \end{array} } \right)$$

The original article [1] has been updated.