Tools | ODS Correlation

Calculates two measures (MAC & SDI) for comparing M#s in two different Data Blocks.

The Modal Assurance Criterion (MAC MAC is an Acronym for Modal Assurance Criterion. MAC indicates whether or not two shapes are co-linear (lie together on the same straight line). If MAC =1 the shapes are co-linear. If MAC > 0.90, the shapes are simlar. If MAC < 0.90 the shapes are different.) and the Shape Difference Indicator (SDI SDI is an Acronym for the Shape Difference Indicator. SDI indicates whether or not two shapes have shape components with the same values in them. SDI values range between 0 & 1. If SDI =1.0 the shapes have identical shape components. If SDI < 1.0 the shapes have different shape components.) are calculated between each sample in one Data Block and the same sample in a second Data Block.

The results are saved as two M#s in a new Data Block.

MAC is a measure of the co-linearity of two shapes. Two shapes are co-linear if they "lie on the same straight line".

This command calculates the MAC between the ODS (M# values) at a sample in one Data Block with the ODS (M# values) at the same sample in a second Data Block.

• MAC has values between 0 & 1

• If MAC = 1, the ODS in one Data Block is co-linear with the ODS at the same sample in the other Data Block

• If MAC < 1, the ODS in one Data Block is different from the ODS at the same sample in the other Data Block

SDI is a measure of the difference between two shapes.

This command calculates the SDI between the ODS (M# values) at a sample in one Data Block with the ODS (M# values) at the same sample in a second Data Block.

• SDI has values between 0 & 1

• If SDI = 1, the ODS in one Data Block is the same as the ODS at the same sample in the other Data Block

• If SDI < 1, the ODS in one Data Block is different from the ODS at the same sample in the other Data Block