Structure#

The CDB contains an entire data set in single computer file. The lookups are performed using the following algorithm:

  • If the slot is empty, the record does not exist. Abort the search.

  • If the slot’s matches the key’s hash, seek to the record. Read and compare.

  • The record is not in this slot. Proceed to next slot, wrapping around to the beginning of the hash table if necessary.

Like already mentioned the data is stored in data structures. These structures are different and depend on the current key. The file database_help_small ‘’CDBase Help’’ explains how the structure looks like and which information is stored in.

For example the following entry is for the basic node data:

CDBASE.CHM description#
@Rec: 020/00 NODE
@0= NR [int]    node-number
@1# INR [int]   internal node-number
@2# KFIX [int]  degree of freedoms
@3# NCOD [int]  additional bit code
@1: XYZ 3[1001] X-Y-Z-ordinates

The data structures equate so called Types in VBA, C#, Python, Fortran, C++ and VB.NET.

Visual Basic for Applications (VBA)#
Type CNODE
  m_NR As Long            'node number
  m_INR As Long           'internal node-number
  m_KFIX As Long          'degree of freedoms
  m_NCOD As Long          'additional bit code
  m_XYZ(1 To 3) As Single '(1 to 1001) X-Y-Z-ordinates
End Type
C##
public unsafe struct cs_node // 20/00 Nodes
{
   public int m_nr;             // node-number
   public int m_inr;            // internal node-number
   public int m_kfix;           // degree of freedoms
   public int m_ncod;           // additional bit code
   public fixed float m_xyz[3]; // [1001] X-Y-Z-ordinates
}
Fortran#
type cnode ! 20/00 Nodes
   sequence
   integer nr    ! node-number
   integer inr   ! internal node-number
   integer kfix  ! degree of freedoms
   integer ncod  ! additional bit code
   real*4 xyz(3) ! [1001] X-Y-Z-ordinates
end type cnode
Python#
class NODE(Structure):
   _fields_ = [ # 20/00 Nodes
      ('m_NR', c_int),       # node-number
      ("m_INR", c_int),      # internal node-number
      ("m_KFIX", c_int),     # degree of freedoms
      ("m_NCOD", c_int),     # additional bit code
      ("m_XYZ", c_float * 3) # [1001] X-Y-Z-ordinates
]
C++#
#define NODE_VER 200501
   typedef struct tagCDB_NODE { /* 20/00 Nodes */
   int m_nr;       /* node-number */
   int m_inr;      /* internal node-number */
   int m_kfix;     /* degree of freedoms */
   int m_ncod;     /* additional bit code */
   float m_xyz[3]; /* [1001] X-Y-Z-ordinates */
} typeCDB_NODE;
VB.NET#
Structure CNODE ' 20/00 Nodes
   Dim m_NR as Integer    ' node-number
   Dim m_INR as Integer   ' internal node-number
   Dim m_KFIX as Integer  ' degree of freedoms
   Dim m_NCOD as Integer  ' additional bit code
   <MarshalAs(UnmanagedType.ByValArray , SizeConst:=3)> Dim m_XYZ() as Single ' [1001] X-Y-Z-ordinates
END Structure

The data type for each value is explicit defined. Also the sequence in which the data is stored in the CDB is fixed. The following files includes an overview of all types and can be found in the corresponding folder:

C:\<sofistik_installation>\2023\SOFiSTiK 2023\interfaces\examples\

  • VBA sofistik_daten.bas

  • VB.NET sofistik_daten.vb

  • C# sofistik_daten.cs

  • C++ *.h

  • Fortran *.for, *.mod

  • Python sofistik_daten.py

Hint

The data-types are generated automatically by SOFiSTiK (per Service-Pack). If you are using another programming language, then you can modify and adapt the data-types to the programming language that you are using.