Encyclopaedia Index

Click here to learn about the two PHOTONS:

PHOTON and WinPHOTON

PHOTON (PHOENICS OuTput optiON) is an interactive graphics program, written in FORTRAN, which can be used to display the results of fluid-flow simulations generated by PHOENICS, or indeed by any other code which produces files in the PHOENICS format, whether for cartesian, polar or body-fitted-coordinate (BFC) grids.

PHOTON reads the PHI (or PHIDA) file written by EARTH and then, in response to instructions from a "PHOTON USE" file, from the keyboard, or from mouse movements over the PHOTON menu, represents the computed grid and the flow pattern graphically and colourfully on the VDU screen. For body-fitted-coordinate calculations to be properly displayed, the XYZ (or XYZDA) file containing cell-corner coordinates must also be read.

PHOTON can draw:-

Additional features include:

Users issue instructions to PHOTON by typing commands on the keyboard or by pressing menu buttons. They can build up and edit pictures interactively, adding or deleting picture elements as they proceed. These picture elements can be viewed from any desired direction, and with any magnification.


PHOTON commands

The PHOTON commands are listed and described under individual PHOTON Help entries in the Encyclopedia.

When running PHOTON, to get help on any item listed above, type the item name followed by a question mark, e.g. 'CONTOUR OFF ?' Items marked with an asterisk (*) give help on selected topics, and are not PHOTON commands, while items marked (R) refer to subcommands of the REPLAY command. Commands marked (U) may only be issued from a USE file.

In help entries, command names are shown thus :-
CON[tour] ON <element number> where the minimum abbreviation for the command is shown in capitals, with the rest of the command in square brackets. Any abbreviation of the full name down to the minimum will be accepted. Parameters are shown in angle brackets; the program will prompt for essential parameters if they are not given on the command line.


PHOTON, disk file requirements

The configuration of PHOTON, in relation to the files it uses, is illustrated below

PGI stands for the PHOENICS Graphics Interface; it is the FORTRAN 'junction-box' which connects PHOTON to graphics software packages such as GKS, PLOT-10/TCS, etc, or to terminals for which direct device drivers are supplied.



         Help file                    Geometry file

                   \               /

    PHI/PHIDA       \             /    / - -  scratch

                _ _  |-----------| ---

    XYZ/XYZDA        |  PHOTON   |      / -   scratch

               _ _   |-----------| --- /

    USE file         |   PGI     |      / -   scratch

                    /|-----------| --- /

                   /       |     /

        TERMINAL  /  LOG file   / _ _ _   SAVE file

The Files Used by PHOTON

When PHOTON is used as a post-processor for EARTH- produced results, it requires access to the 'fields' file PHI (or PHIDA), which provides field values of all variables which are stored or solved. If flows are simulated in BFC (ie body-fitted coordinate) grids, PHOTON additionally requires access to the grid file XYZ (or XYZDA) which contains the grid coordinates.

When PHOTON is used as a pre-processor, for examination of BFC grids, it requires access only to the grid file. When PHOTON is used to replay previously stored pictures, neither a 'fields' file nor a grid file is needed.


PHOTON HELP

Photon Help ----

Help is available under the following headings :-



    BLOCK                    CLEAR                    CLEAR (R)

    COLOUR                   CONTOUR CLEAR            CONTOUR DELETE

    CONTOUR OFF              CONTOUR ON               CONTOURS

    COORDINATES              DASH                     DOMAIN

    DRAW (R)                 DUMP                     DUMP (R)

    END                      ESCAPE                   EXTRAPOLATE

    FILE (R)                 GEOMETRY (*)             GEOMETRY CLEAR

    GEOMETRY DELETE          GEOMETRY OFF             GEOMETRY ON

    GEOMETRY READ            GEOMETRY SAVE            GEOMETRY_CMDS (*)

    GRID CENTRE              GRID CLEAR               GRID DELETE

    GRID HATCH             GRID OFF                 GRID ON

    GRID OUT               GRIDS                    HATCH

    LIST (R)               LOG                      MAGNIFY GRID

    MIRROR                 MONOCHROME (R)           NEWS (*)

    NOCLEAR (R)            PAUSE                    PHI

    PICS (*)               PREFIX_FILE (*)          REDRAW

    REDRAW (R)             REPLAY                   RESET (R)

    ROTATE                 SAVE                     SCALE (R)

    SCREEN                 SENDP                    SENDP (R)

    SET                    SET AXES                 SET BOX

    SET CONTOUR FILL       SET CONTOUR SCALE        SET CONTOUR UNITS

    SET GEOMETRY           SET HOLD                 SET LHAND

    SET ORDER              SET POROSITY             SET PROPERTY

    SET RHAND              SET VECTOR AVERAGE       SET VECTOR BOUNDARY

    SET VECTOR CENTRE      SET VECTOR COMPONENTS    SET VECTOR KEY

    SET VECTOR PHASE       SET VECTOR REFERENCE     SET VECTOR UNITS

    SHIFT (R)              SHOW                     STOP

    STREAM                 STREAM 2DIMENSTION       STREAM 3DIMENSTION

    STREAM CLEAR           STREAM DELETE            STREAM OFF

    STREAM ON              SURFACE CLEAR            SURFACE DELETE

    SURFACE OFF            SURFACE ON               TEXT

    TEXT CLEAR             TEXT COLOUR              TEXT DELETE

    TEXT LIST              TEXT MOVE                TEXT REPLACE

    TEXT SIZE              TEXT UNDERLINE           UMAGNIFY GRID (U)

    UP                     UPAUSE (U)               UREWIND (U)

    USE                    USHIFT (U)               UTEXT (U)

    VECTOR CLEAR           VECTOR DELETE            VECTOR OFF

    VECTOR ON              VECTORS                  VIEW

    WHERE (R)              XYZ                      4VIEW (R)

To get help on any item listed above, type the item name followed by a question mark, e.g. 'CONTOUR OFF ?'. Items marked with an asterisk (*) give help on selected topics, and are not PHOTON commands, while items marked (R) refer to subcommands of the REPLAY command. Commands marked (U) may only be issued from a USE file.

In help entries, command names are shown thus :-
CON[tour] ON <element number> where the minimum abbreviation for the command is shown in capitals, with the rest of the command in square brackets. Any abbreviation of the full name down to the minimum will be accepted. Parameters are shown in angle brackets; the program will prompt for essential parameters if they are not given on the command line.

Note also that PHOTON contains a built-in set of tutorials, which are accessed by typing m on the command line.

This Encyclopaedia article describes the pre-Windows PHOTON. Those who prefer the Windows 'look-and-feel' can read about the more-modern WinPHOTON by clicking here.



PHOTON help; further information

The following PHOTON items are provided here because they cannot be conveviently placed elsewhere in an alpahabetically- ordered encyclopaedia.

+X

----------------------------------------- Photon Help ----

The vector is in positive X direction.


+Y

----------------------------------------- Photon Help ----

The vector is in positive Y direction.


+Z

----------------------------------------- Photon Help ----

The vector is in positive Z direction.


-X

----------------------------------------- Photon Help ----

The vector is in negtive X direction.


-Y

----------------------------------------- Photon Help ----

The vector is in negtive Y direction.


-Z

----------------------------------------- Photon Help ----

The vector is in negtive Z direction.


/

------------------------------------------ Photon Help ----

Escape sequence


PHOTON, picture elements

A PHOTON picture is composed of 'elements'. There are six types of element, namely: grid, vector, contour, surface, streamlines, text and geometry. All elements are stored as they are created, and may be combined to produce the desired picture.

GRID I 1

produces the first I plane as an element. The notation used to specify grid surfaces is described in TR140, Chapter 2, Section 2.5.

VEC IY 1

causes vectors over the first IY plane to be plotted.

SURF TEMP X 0.5

will draw, on each IX plane, a contour line of the variable TEMP at a value of 0.5.

STR 2D Z 1

causes streamlines to be drawn on the plane Z=1 in a 2D case.

All elements remain available until the end of the program run, or until they are deleted individually or by the CLEAR command.


PHOTON, startup

When you run PHOTON in command mode, the CHAM logo, site- installation details and a copyright message are displayed, on the screen. After this, you should select the graphical-output device you wish to use.

If the system in use supports only a single type of graphics device, then no menu will appear, and PHOTON will display only the logo and the 'Press RETURN to continue' message.

If more than one device is available, PHOTON will display a menu from which you should select the number that corresponds to the graphics device in use. The list of screen devices displayed will reflect those available at the local site.

Once the graphics-screen device has been selected, the graphics- screen or window is initialised and the PHOTON box is displayed. The PHOTON box contains the drawing area, the CHAM logo and the axes. The start-up screen also contains a reminder of the top-level commands for attaching files, for entering the replay facility and for accessing the on-line help system.


PHOTON, termination of

Entering END or STOP will terminate the PHOTON session.


PHOTONLOG

---------------------------------- Photon Help ----

After pressing this button, type in a name for the new PHOTON LOG file which will save subsequent commands and key strokes. The default name is PHOLOG that is opened at the same time when the graphic device is opened. Once a new file name has been given the old LOG file will be closed and saved.

PHOTONUSE

---------------------------------- Photon Help ----

After pressing this button, type in the file name of a PHOTON USE file.


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