vcs emulation error in ubuntu system

[huaiwangyu]

reveal：
Warning-[STASKW_CO1] Cannot open file
The file 'data.pat' could not be opened. No such file or directory.
Please ensure that the file exists with proper permissions.

Warning-[STASKW_RMCOF] Cannot open file
../logical/tb/tb.v, 137
Cannot open file 'data.pat' passed as argument to $readmem.
Please verify that the first argument to $readmem is a file that exists with
proper permissions.

Could someone please tell me what the problem is, or how to fix it