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1.5.2 The global menus

Using the menus the user creates, edits, destructs and so on objects stored in two databases (DB), one for the geometry and the other for meshes.

Selection menus

   These menus, shown at the bottom of the graphics window, make it possible to select the type of graphics selection we want (a point, a straight line, etc.). They depend on the application currently being used (cf. figures 1.18, 1.19, 1.20). It is absolutely essential to understand the outputs of these menus because all the rest depends on their functioning. All these outputs, for example, a circle, a number or the extremity of an arc, are marked (?) and the marks (or types ?) define the selection syntactical entities known by the grammars which manage the three applications.

 
Figure 1.18: The select menu for the CONSTRUCTION application 

 
Figure: The select menu for the PREP_MESH application 

 
Figure: The select menu for the EDIT_MESH application 

The constructible types are :

• <COORD>  current point (mouse point, XY Point or extremity, center, middle of an element of the DB)
• <POINT>  point of the DB
• <LINE>  straight line of the DB
• <CIRCLE>  circle of the DB
• <ARC>  arc of the DB
• <SEGMENT>  segment of the DB
• <SPLINE>  spline of the DB
• <VALUE>  numerical value (entered with the calculator)
• <VERTEX>  vertex of the mesh
• <EDGE>  edge of the mesh
• <ELEMENT>  finite element (triangle or quadrangle) of the mesh
• S_DOM  subdomain of the mesh (connected component of the mesh)

These menus depend on the application being used as they define the type of element to be selected. The menu ITEMs  (their keyboard shortcut  is in parenthesis) can be classified in several categories.

1. the items POINT (p), STRT LINE (l), CIRCLE (c), ARC (a), SEGMENT (s),
   [4] SPLINE (~) are used to select the element of the DB          closest to the clicked point, the type of selection depends on the kind of element found and by the item in categories (4), (5) that is used. If there is an incompatibility, the item in category (4) is forced to change to(?) NEAREST.

2. The items MOUSE P  (m), XY POINT  (x), XY FILE   (<) are used to enter current points respectively as follows:
   • points can be defined by clicking the mouse in the graphic window;
   • points can be defined by a list of couples of values (coordinates) entered with the calculator;
   • points can be read from a `FORMATTED' file containing 2 coordinates (real) per line up to the end of the file (EOF), the name of the file is requested in the scratch zone;
   Note: in the last two cases the point created can be outside the graphic window;

3. the ANY  (q) item has no effect on the selection: the element of the DB closest to the clicked point is selected. The type of selection depends on the kind element found and by the item in categories 4, 5 that is used.

4. the NEAREST  ( n)item is used to effectively select an element of the DB and the type of selection is that of the element.

5. the EXTREM(ITY)  ( e), CENTER  ( c), MIDDLE  ( m) items are used to define what we are going to select in the element of the DB (cf. (1) and (3)), i.e., we select the point (selection type COORD) that is respectively the extremity, the center or the middle of the selected DB element, if this makes sense. Otherwise, the main mode of selection is forced to change to ANY, cf. 3. while keeping the item in category 5.

6. the INTERSECTION (i) item is used to select the current point which is the intersection of 2 elements of the DB selected in the next paragraph (the selection type generated is COORD).

7. the ELEMENT (f), EDGE (d), VERTEX (v), S_DOM (r) items are used to select respectively the element---either triangle or quadrangle---containing the clicked point, this is for the selection type ELEMENT, the edge in an element closest to the clicked point, this is for the selection type EDGE, , the vertex in an element closest to the clicked point, this is for the selection type VERTEX or the subdomain containing the clicked point, this is for the selection type S_DOM.

Important note: In effect, the selection only becomes effective after we have clicked on an element in the graphic window. It is possible to click in the menu items as many times as we want so as to obtain a combination of marked items. A selection defines the type of selection and it preserves the cursor coordinates at the instant of the click. These coordinates are often useful for the application being used to remove semantic ambiguities or choose between multiple solutions to the problem being treated. For example,

• if we want to construct a circle tangent to 3 circles, there are generally 8 solutions. The program will choose the solution such that the points of tangency are closest to the selection points,
• the intersection of two circles gives two points. In INTERSECTION, the ambiguity is removed by retaining the point closest to the one used to select the second circle.

If we try to select something that does not exist, we get the message you have selected nothing, which has no effect whatsoever.

The selections possible depend on the application since all types of selection are not always needed. For example, circles and straight lines are only used in the CONSTRUCTION application, elements, edges, vertices and subdomains only exist in the EDIT_MESH application.

Shortcuts

Keyboard shortcuts  that correspond to ITEMs of categories 1,2,3,4,7 are equivalent to 2 clicks, the first in the ITEM box and the following on the cursor point if it is in the graphic window. Thus the mode of selection has now changed and it is the element closest to the cursor which is selected.

Practical utilization

An element is selected by clicking next to it (the program searches for the element closest to the click). When we click a menu, it is marked with a > sign in front of the text of the menu. In the selection menus, two boxes can be marked at the same time according to the following combinations:

item	(shortcut)	( possible combinations)
ANY	(q)	( NEAREST, EXTREMITY, CENTER, MIDDLE )
POINT	(p)	( NEAREST)
STRT LINE	(l)	( NEAREST)
CIRCLE	(c)	( NEAREST, CENTER )
ARC	(a)	( NEAREST, EXTREMITY, CENTER, MIDDLE )
SEGMENT	(s)	( NEAREST, EXTREMITY, MIDDLE )
SPLINE	(~)	( NEAREST, EXTREMITY )
MOUSE P	(m)	( NEAREST)
XY POINT	(x)	( NEAREST)
VERTEX	(v)	( NEAREST)
EDGE	(d)	( NEAREST)
ELEMENT	(f)	( NEAREST)
S_DOM	(r)	( NEAREST)

Other combinations are not valid. A selection is not effective except when an element on the screen has been clicked. In fact the boxes may be clicked as many times as necessary to obtain the desired combination.

The calculator menu

   This menu (cf. figure 1.21)  can also be considered as a selection menu. It can be used to define a numerical value which is of type <VALUE>  .

 
Figure 1.21: The two calculator menus 

We can write any FORTRAN expression. The effective computation is achieved by clicking on the = box (shortcut =) or by typing (CR)  .

The ITEMs with their keyboard shorcut  between parentheses are:

Cell	shortcut	Comment
1	(1)	numbers
2	(2)
3	(3)
4	(4)
5	(5)
6	(6)
7	(7)
8	(8)
9	(9)
.	(.)	decimal point
+	(+)
-	(-)
*	(*)
/	(/)
)	())
(	(()
,	(,)	comma, separator for function arguments
=	(=)
|	(|)	exponentiation operator
PI		=
Y		= 0
NO		= 1
E	(E)	exponent for numbers in exponential format
C	(Z)	resets the calculator accumulator
AC	(R)	resets the calculator
Ra		= radius of a selected element (ARC or CIRCLE)
Ag		= angle of a selected element (ARC)
		or angle between two STRT LINE
Lg		= length of a selected element (ARC or SEGMENT
		or SPLINE).
Di		= distance between a POINT and another POINT, a STRT LINE, a CIRCLE or an ARC;
		or distance between two parallel STRT LINE;
		or distance between two CIRCLE.
POP		used to display the calulator menu of FORTRAN functions SIN  , COS  , TAN  , ASIN  , ACOS  , ATAN  , ATAN2 , EXP  , LOG  , LOG10 , INT  , NINT  , MOD  .

Examples: to enter

1.234567E9

type 1.234567E9(CR)

0.5

type 1/2=

3.14159...

click the PI box and type (CR)

2circle radius

type 2*, click the Ra box, then select the circle (by clicking the circle box of the selection menu then clicking near the circle in the graphic window) and finally type (CR)  .

The general menu

  This menu (cf. figure 1.22) is used to perform general operations: move between CONSTRUCTION, PREP_MESH and EDIT_MESH, save, restore, screen copy or execute a system command. To initiate an operation, click in the corresponding item.

 
Figure 1.22: The general menu 

The operations of the general menu are:

Exiting the program

QUIT

  Terminates the execution of the program.

Querying the database

QUERY

  Queries the selected elements. Their characteristics are displayed in the input-output or scratch zone.

Destructing elements of the database

DESTRUCT

  Only available in the CONSTRUCTION application. Destructs selected elements of the database. Warning: if we destruct a POINT, the program checks if this POINT is used to define a SPLINE. If this is the case, it is also removed from the SPLINE.

Saving the database

SAVE

  Saves the DB  in a file. The name of the file is composed a prefix and a suffix. The system asks for the prefix in the scratch zone (figure 1.9). According to the case, the suffix can be .emc2_bd, .mesh, .nopo, .am, .am_fmt, .amdba and it depends on the current application:

• In the CONSTRUCTION application, construction elements are saved together with their reference number (points, straight lines, circles, arcs, segments and splines). The state of the system is saved as well. The suffix is .emc2_bd.

• In the PREP_MESH application, SAVE works the same as in CONSTRUCTION. Additionally, the definition of the domains is saved. The suffix is .emc2_bd.

• In the EDIT_MESH application, different types of meshes can be saved. The type is entered in the scratch zone, before entering the file prefix. Implicitly known types are:

  mesh

  (default) The MESH_DB  is saved  with its references to the DB  defining the geometry, i.e., the contours of the subdomains. The suffix is .mesh.

  nopo

    A Modulef NOPO  data structure is extracted from the MESH_DB and written in a file with suffix .nopo. The curves defining the contours are lost.

  am

    An AM-type  simplified structure---see appendix 1.5.8---is extracted from the MESH_DB and written in a nonformatted file with suffix .am. The curves defining the contours and the edge references are lost.

  am_fmt

     Same as am. However, the storage file is formatted with suffix .am_fmt, see appendix 1.5.8.

  amdba

  An AMDBA-type    structure (see appendix 1.5.8) is extracted from the MESH_DB and written in a formatted file with suffix .amdba. The curves defining the contours and certain references are lost.

  Remark: It is possible to save meshes under other formats by modifying the ecrmsh  subroutine.

Restoring the database

RESTORE

  Restores the DB of a file. The name of the file is composed of a prefix and a suffix. The system asks for the prefix in the scratch zone (figure 1.9). According to the case, the suffix can be .emc2_bd, .mesh, .nopo, .am, .am_fmt, .amdba. The data restored depend on the current application.

• In the CONSTRUCTION application, construction elements are restored together with their reference number (points, straight lines, circles, arcs, segments and splines). The state of the system is restored as well. The suffix is .emc2_bd.

• In the PREP_MESH application, RESTORE works the same as in CONSTRUCTION. Additionally, the definition of the domains is saved. The suffix is .emc2_bd.

• In the EDIT_MESH application, different types of meshes can be restored. The type is entered in the scratch zone, before entering the file prefix. Implicitly known types are:

  mesh

  restores a mesh and its contours, whose geometrical definitions are saved. The suffix is .mesh.

  nopo

  The MESH_DB is constructed from a Modulef NOPO data structure. The curves defining the contours are reconstructed with segments and crack edition is lost. The suffix is .nopo.

  am

  The MESH_DB is constructed from an AM-type structure, see appendix 1.5.8. The curves defining the contours are reconstructed with segments. Crack and edge reference edition are lost. The suffix is .am.

  am_fmt

  Same as am. However, the file is formatted with suffix .am_fmt, see appendix 1.5.8.

  amdba

  The MESH_DB is constructed from an AMBDA-type structure, see appendix 1.5.8. The curves defining the contours are reconstructed with segments and crack edition is lost. The suffix is .amdba.

  Remark: It is possible to restore meshes saved under other formats by modifying the addmsh  subroutine.

  Caution: The recently read mesh is not merged with already existing meshes.

Resetting

DB_RESET

  Clears everything stored in the 2 databases.

Printing the screen

HARD_COPY

  Makes a bitmap, screen resolution, hard copy of the screen. Depends on the system and on the environment (cf. hardcp  subroutine).

Redrawing the window on another graphic peripheral device

SOFT_COPY

  Displays the screen on another Fortran 3d peripheral device. Depends on the system and on the environment (cf. softcp  subroutine)

Executing a system command

SHELL

  Executes a system command  (shell). The system asks for the the command(s) in a character string. Depends on the system (cf. exec  subroutine).

Saving a run

LOG FILE

   Saves all user operations in a file. The file name is composed of prefix given by the user and the suffix .trace_emc2. If the prefix starts with a + sign, it is appended to the trace file. A default trace file is open. Its prefix is tracexxxx, where xxxx is a version number in order not to erase the previous trace.

Reexecuting a run

INTERPRET

  Interprets a trace file. The prefix is given by the user.

Moving to the CONSTRUCTION application

CONSTRUCTION

Moves to the CONSTRUCTION  application. After the move, the selection mode is MOUSE P.

Moving to the PREP_MESH application

PREP_MESH

  Moves to the PREP_MESH application. After the move, the selection mode is MOUSE P.

Moving to the EDIT_MESH application

EDIT_MESH

  Moves to the EDIT_MESH application. When the move occurs and after the 4 questions have been answered, the program triangulates all the defined domains. If no domain has been defined, everything is meshed. The triangulation depends on 4 parameters. To get the default value, type (CR)

for each parameter.

1. a debug parameter (default=0) that defines two other parameters:
   • impression =debug mod 10 : 0 => no printing, 9 => a lot of printing
   • graphic debugging = debug / 10 : 0 => no debugging, 9 => all the phases of the meshing algorithm are displayed ( this is very slow).
2. a puis parameter of refinement depth. The smaller puis is, the larger will refinement zones develop. puis = .25 is the default value. Reasonable values are between .1 and 10.
3. a coef parameter of triangle density. The number of triangles generated is in . coef = .75 is the default value.
4. furthermore, the system asks whether a regularization is to be applied (default is yes);

The screen management menu

  The screen management menu is shown in figure 1.23. It is present in all applications. It is used to handle the display of both databases. The display context consists in storing a display mask . This mask is a rectangle in subject space, computed so as to preserve the same scales  in X and Y. The display context stack is in fact an 8 level circular stack. It is initialized as: scale 1, mask centered at the origin.

 
Figure 1.23: The screen management menu 

The operations of the screen management menu are:

Enlarging the display

  ZOOM + COORD COORD

The rectangle defined by the two COORD is displayed full screen. The new display context is stacked in the display stack. In general, we click two times to define two opposite corners of the rectangle.

Reducing the display

  ZOOM - COORD COORD

The contents of the full screen is displayed in the rectangle defined by the two COORD. The new display context is stacked in the display stack.

Translating the graphic window

  TRANSLATION COORD COORD

Translates the graphic window by vector going from the first COORD to the second COORD. The new display context is stacked in the display stack.

Defining a scale

  SCALE

Changes the display scale without moving the center of the window. The new display context is stacked in the display stack.

Redrawing the graphic window

  REFRESH

Redraws the current display. This operation is very useful to erase unwanted residues that are often present.

Centering the display

  C_MASK COORD

Centers the window on the selected point COORD. The new display context is stacked in the display stack.

Redrawing the previous display

  PREVIOUS

Goes down one level in the display context stack. The previous display context is restored.

Note: this context always exists because all eight levels are initialized by default.

Redrawing the next display

  NEXT

Goes up one level in the display context stack. The next display context is used, see note above.

Drawing the whole display

  SHOW_ALL

Computes the mask so as to show the whole database and displays it full screen.