This function is used to get the matrix data in OP4 file output by MSC Nastran
Input Parameter: filename
Output Parameter: matrix_data
ONLY 3E23.16 DIGITAL TYPE CAN BE USED TEMPORARILY
MSC Nastran DMAP script demo shown bellow
ASSIGN OUTPUT4='QHH.op4' UNIT=101 FORMATTED
ASSIGN OUTPUT4='QKH.op4' UNIT=102 FORMATTED
SOL 145
DIAG 8,14
COMPILE FLUTTER
ALTER 56 $ MSC NASTRAN 2019
OUTPUT4 QHH,,,,///101///16 $
OUTPUT4 QKH,,,,///102///16 $