## NAME

         rect_cen_in_rect - bitmap generator for rectangular  conduc-
         tor inside rectangular conductor (part of atlc)

## SYNOPSIS

         rect_cen_in_rect [options... ] W H w h Er

## WARNING

         This man page is not a complete set  of  documentation.  See
         the  html  files for more complete information. So far, I've
         not managed to install the html files  into  /usr/local,  so
         you  will  have to look into the atlc-2.X.Y.Z/docs/html-docs
         directory for them.

## DESCRIPTION

         rect_cen_in_rect is a pre-processor  for  atlc,  the  finite
         difference  programme  that is used to calculate the proper-
         ties of a  two-conductor  electrical  transmission  line  of
         arbitrary  cross  section. The programme rect_cen_in_rect is
         used as a fast way of generating bitmaps (there is  no  need
         to  use  a  graphics programme), for a rectangular conductor
         placed centrally inside another rectangular conductor,  like
         this:

         -----------------------------------------------------  ^
         |                                                   |  |
         |            Dielectric, permittivity=Er            |  |
         |                                                   |  |
         |                                                   |  |
         |                                                   |  |
         |             <----------w----------->              |  |
         |             ------------------------   ^          |  |
         |             |                      |   |          |  |
         |             |  Metallic conductor  |   |          |  H
         |             |  conductor (must be  |   h          |  |
         |             |  in  the centre)     |   |          |  |
         |             |                      |   |          |  |
         |             ------------------------   ^          |  |
         |                                                   |  |
         |                                                   |  |
         |                                                   |  |
         |                                                   |  |
         |                                                   |  |
         |                                                   |  |
         -----------------------------------------------------  |
         <---------------------------W----------------------->

         The parameters 'W' and 'H' and the inner dimensions  of  the
         outer  conductor.  The outer dimensions of the inner conduc-
         tor are 'w' and 'h'. The inner conductor is  assumed  be  be
         placed  centrally  inside  the  outer  conductor. The spaced
         between the two conductors is filled with  a  dielectric  of
         relative permittivity Er

         The bitmap is printed to standard output, which MUST be  re-
         directed  to either a file, or piped into the standard input
         of atlc, in one of the following two ways.

         rect_cen_in_rect W H w h Er > filename.bmp OR
         rect_cen_in_rect -f filename.bmp W H w h Er

         The bitmaps produced  by  rect_cen_in_rect  are  24-bit  bit
         colour bitmaps, as required by atlc.

         The permittivity of the bitmap, set by 'Er',  determine  the
         colours  in  the  bitmap. If Er is 1.0, 2.1, 2.2, 2.33, 2.5,
         3.3, 3.335, 4.8 or 10.2, then the  colour  corresponding  to
         that  permittivity  will  be  set  according  to the colours
         defined in COLOURS below. If Er is not one of those  permit-
         tivities,  the  region of permittivity Er will be set to the
         colour 0xCAFF00. The programme atlc does not know what these
         permittivites  are,  so  they  atlc,  must  be told with the
         comand line option -d, as in example 4 below.

## OPTIONS

         -b bitmapsize
         is used to set the size of the bitmap, and so  the  accuracy
         to  which  atlc is able to calculate the transmission line's
         properties. The default value for 'bitmapsize'  is  normally
         4,  although  this  is set at compile time. The value can be
         set anywhere from 1 to 15, but more than 8 is  probably  not
         sensible.

         -f outfile
         Set the output filename. By default, the bitmap is  sent  to
         stdout,  but  it *must* be sent to a file, with this option,
         or as described above.

         -v
         Causes rect_cen_in_rect to print some data to stderr.  Note,
         nothing  extra  goes to standard output, as that is expected
         to be redirected to a bitmap file.

## COLOURS

         The 24-bit bitmaps that atlc expects, have 8  bits  assigned
         to  represent the amount of red, 8 for blue and 8 for green.
         Hence there are 256 levels of red, green and blue, making  a
         total of 256*256*256=16777216 colours. Every one of the pos-
         sible 16777216 colours can be defined precisely by the stat-
         ing the exact amount of red, green and blue, as in:

         red         = 255,000,000 or 0xff0000
         green       = 000,255,000 or 0x00ff00
         blue        = 000,000,255 or 0x0000ff
         black       = 000,000,000 or 0x000000
         white       = 255,255,255 or 0xffffff
         Brown       = 255,000,255 or 0xff00ff
         gray        = 142,142,142 or 0x8e8e8e

         Some colours, such as pink, turquiose,  sandy,  brown,  gray
         etc  may mean slightly different things to different people.
         This is not so with  atlc,  as  the  programme  expects  the
         colours  below  to  be EXACTLY defined as given. Whether you
         feel the colour is sandy or yellow is up to you, but if  you
         use  it  in your bitmap, then it either needs to be a colour
         recognised by atlc, or you must define  it  with  a  command
         line option (see OPTIONS and example 5 below).
         The following conductors are recognised by atlc:
         red    = 255,000,000 or 0xff0000 is the live conductor.
         green  = 000,255,000 or 0x00ff00 is the grounded conductor.
         blue   = 000,000,000 or 0x000000 is the negative conductor

         All bitmaps must have the live (red)  and  grounded  (green)
         conductor.  The  blue  conductor is not currently supported,
         but it will be used to indicate a negative conductor,  which
         will  be  needed  if/when  the  programme  gets  extended to
         analyse directional couplers.

         The following dielectrics are recognised by atlc and so  are
         produced by rect_cen_in_rect.

         white      255,255,255 or 0xFFFFFF as Er=1.0   (vacuum)
         pink       255,202,202 or 0xFFCACA as Er=1.0006 (air)
         light blue 130,052,255 or 0x8235Ef as Er=2.1   (PTFE)
         Mid gray   142,242,142 or 0x8E8E8E as Er=2.2   (duroid 5880)
         mauve         255.000,255    or    0xFF00FF    as    Er=2.33
         (polyethylene)  yellow     255,255,000 or 0xFFFF00 as Er=2.5
         (polystyrene)
         sandy      239,203,027 or 0xEFCC1A as Er=3.3   (PVC)
         brown      188,127,096 or 0xBC7F60 as Er=3.335 (epoxy resin)
         Terquoise  026,239,179 or 0x1AEFB3 as Er=4.8   (glass PCB)
         Dark gray  142,142,142 or ox696969 as Er=6.15  (duroid 6006)
         L. gray    240,240,240 or 0xDCDCDC as Er=10.2  (duroid 6010)
         D. orange  213,130,067 or 0xD5A04D as Er=100.0  (mainly  for
         test purposes)
         If the permittivity is one not in the above list, then those
         parts of the image with Er will be set to 0xCAFF00.

## EXAMPLES

         Here are a few examples  of  the  use  of  rect_cen_in_rect.
         Again,  see  the html documentation in atlc-X.Y.Z/docs/html-
         doc/index.html for more examples.

         1) In the first example, there is just a vacuum  dielectric,
         so  Er=1.0.   The  inner of 1x1 inches (or mm, miles etc) is
         placed centrally in an  outer  with  dimensions  3.3  x  3.9
         inches.

         % rect_cen_in_rect 3.3 3.9 1 1 1 > 1.bmp
         % atlc 1.bmp

         2) In this second example, an inner of 15.0 mm x 5.0  mm  is
         surrounded  by  an  outer with internal dimensions of 71.5 x
         60.0 mm. There is a material with permittivity  2.1  (Er  of
         PTFE)   around   the   inner   conductor.  The  output  from
         rect_cen_in_rect is sent to a file 2.bmp, which is then pro-
         cessed by atlc

         % rect_cen_in_rect 71.5 60.0 15.0 5.0 2.1 > 2.bmp
         % atlc 2.bmp

         3) In example 3, the bitmap  is  made  larger,  to  increase
         accuracy,  but  otherwise  this  is  identical to the second
         example. % rect_cen_in_rect -b7 71.5 60 15 5 2.1 > 3.bmp
         % atlc 3.bmp

         In   the   fourth   example,   instead    of    re-directing
         rect_cen_in_rect's  output  to a file with the > sign, it is
         done using the -f option.
         % rect_cen_in_rect -f 4.bmp 61.5 28.1 5 22 2.1
         % atlc 4.bmp

## SEE ALSO

         atlc(1), circ_in_circ(1). rect_in_rect(1),  circ_in_rect(1).
         rect_in_circ(1), readbin(1) and sym_strip(1).

         http://atlc.sourceforge.net                - Home page
         http://sourceforge.net/projects/atlc       - Download area
         atlc-X.Y.Z/docs/html-docs/index.html       - HTML docs
         atlc-X.Y.Z/docs/qex-december-1996/atlc.pdf - theory paper
         atlc-X.Y.Z/examples                        - examples
         http://www.david-kirkby.co.uk              - my home page
         http://www.david-kirkby.co.uk/ham          - ham radio pages