Display | MAC

Calculates and displays Modal Assurance Criterion (MAC) values between pairs of shapes in two Shape Tables.

What is MAC?

A MAC value is a quantitative method for comparing two complex shape vectors, {u} and {v}.  MAC values range between 0 & 1;

MAC is calculated between two shapes {u} and {v} with the formula;


|| ||2 - denotes the magnitude squared of the vector.

MAC 3D Bar Chart.

WARNING: Only the shape components with matching shape DOFs in the two Shape Tables are used to calculate MAC values.

What is CoMAC?

Coordinate Modal Assurance Criterion (CoMAC) values can also be calculated and displayed between the shape components (or shape DOFs) of pairs of shapes in two Shape Tables. Each Shape Table can contain ODS's, FEA Mode Shapes, EMA Mode Shapes, or Engineering Data Shapes. CoMAC compares shape components from two rows of the DOFs spreadsheets of two Shape Tables.

CoMAC uses the same formula as MAC, but {X} and {Y} are vectors of data from two rows instead of two columns of the M#s spreadsheets.  CoMAC values also range between 0 & 1.

MAC Window Commands

The following additional commands are contained in the MAC window.

File | Copy Graphics to Clipboard

Copies the MAC window graphics to the Windows Clipboard.

File | Print

Prints the graphics on the system graphics printer.

File | Close

Closes the MAC window.

Display | Spreadsheet

Displays the MAC or CoMAC values in a spreadsheet.

Display | 3D Bar Chart

Displays the MAC or CoMAC values in a 3D bar chart.

Display | Values

When checked, the MAC or CoMAC value for one shape pair is displayed on the 3D Bar Chart.

Display | MAC, CoMAC

When checked, either MAC or CoMAC values are displayed in either a 3D Bar Chart or a spreadsheet.

Structure Options Animation Tab

When this option is enabled, a Show MAC control is added to the Animation Tab in the File | Structure Options box .