## NAME

         circ_in_rect - bitmap generator  for  a  circular  conductor
         inside a rectangular conductor (part of atlc)

## SYNOPSIS

         circ_in_rect [options... ] d W H x y 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-X.Y.Z/docs/html-docs
         directory for them.

## DESCRIPTION

         circ_in_rect is a pre-processor for atlc, the finite differ-
         ence programme that is used to calculate the properties of a
         two-conductor  electrical  transmission  line  of  arbitrary
         cross  section. The programme circ_in_rect is used as a fast
         way of generating bitmaps (there is no need to use a  graph-
         ics  programme), for a circular conductor inside a rectangu-
         lar conductor, like this:

         --------------------------------------------------------  ^
         |                                                      |  |
         |                                                      |  |
         |                                                      |  |
         |                                                      |  |
         |                                                      |  |
         |           Dielectric, permittivity=Er                |  |
         |                                                      |  |
         |                                                      |  |
         |                                                      |  |
         |                                                      |  |
         |         <------x------> ^                            |  H
         |       *****             |                            |  |
         |    ***********          y                            |  |
         |   *************         |                            |  |
         |   **************        |                            |  |
         |   <-----d------>        v                            |  |
         |   **************                                     |  |
         |   *************                                      |  |
         |    ***********                                       |  |
         |        ***                                           |  |
         |                                                      |  |
         -------------------------------------------------------   v
         <---------------------------W-------------------------->

         The parameters 'W' and 'H' and the inner dimensions  of  the
         outer  conductor.  The inner conductor has a diameter of 'd'
         and is offset from the centre of the outer conductor  by  an
         amount  'x'  horizontally  and  'y'  vertically.   The space
         between the inner and outer conductors is  a  dielectric  of
         relative  permittivity  'Er'.  If  there  is  just  a vacuum
         dielectric, then 'Er' should be set to 1.0

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

         circ_in_rect  d W H x y Er > filename.bmp OR
         circ_in_rect -f filename.bmp d W H x y Er

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

         The permittivities of the bitmap, set by 'Er', determine the
         colours in the bitmap. If Er1 is 1.0, 1.006, 2.1, 2.2, 2.33,
         2.5,  3.3,  3.335,  4.8,  10.2  or  100  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  permittivities, the region of permittivity Er will be
         set to the colour 0xCAFF00. The programme atlc does not know
         what these permittivites are, so atlc, must be told with the
         -d command line option, 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 circ_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.
         black  = 000,000,000 or 0x000000 is the negative conductor

         All bitmaps must have the live (red)  and  grounded  (green)
         conductor.  The  black 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 circ_in_rect.

         white     255,255,255 or 0xFFFFFF as Er=1.0   (vacuum)
         white     255,202,202 or 0xFFCACA as Er=1.0006 (air)
         blue      000,000,255 or 0x0000FF 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 213,160,077 or 0xD5A04D as Er=100   (for testing)
         If the permittivity is one not in the above list, then those
         parts  of  the  image  with Er1 will be set to 0xCAFF00, and
         those parts with Er2 to 0xAC82AC.

## EXAMPLES

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

         In the first example, there is just an  air  dielectric,  so
         Er1=Er2=1.0.   The inner of 1x1 inches (or mm, miles etc) is
         placed centrally in an outer with dimensions 3 x 3 inches.

         The exact place where the  dielectric  starts  (a)  and  its
         width (d) are unimportant, but they must still be entered.

         % circ_in_rect 3 3 1 1 1 1 1 1 > ex1.bmp
         % atlc ex1.bmp

         In this second example, an inner of 15.0 mm x 0.5 mm is sur-
         rounded  by an outer with internal dimensions of 61.5 x 20.1
         mm. There is a material with permittivity 2.1 (Er  of  PTFE)
         below  the  inner conductor. The output from circ_in_rect is
         sent to a file ex1.bmp, which is then processed by atlc

         % circ_in_rect 61.5 20.1 5 22 0.5 50 15 5 1.0 2.1 > ex2.bmp
         % atlc ex2.bmp

         In example 3, the bitmap is made larger, to  increase  accu-
         racy, but otherwise this is identical to the second example.
         % circ_in_rect -b7 61.5 20.1 5 22 0.5 50  15  5  1.0  2.1  >
         ex3.bmp
         % atlc ex3.bmp

         In   the   fourth   example,   instead    of    re-directing
         circ_in_rect's  output to a file with the > sign, it is done
         using the -f option.
         % circ_in_rect -f ex4.bmp 61.5 20.1 5 22 0.5 50 15 5 1.0 2.1
         % atlc ex4.bmp

         In the fifth example, materials with permittivites 2.78  and
         7.89  are  used.  While  there  is  no  change in how to use
         circ_in_rect, since these permittivities are not  known,  we
         must tell atlc what they are.

         % circ_in_rect 61 20 1 4 22 0.5 50 15 5 2.78 7.89 >  ex5.bmp
         % atlc -d CAFF00=2.78 -d AC82AC=7.89 ex5.bmp

         In the sixth and final example, the -v  option  is  used  to
         print some extra data to stderr from circ_in_rect.

## SEE ALSO

         atlc(1),        rect_cen_in_rect(1),        circ_in_circ(1).
         rect_in_circ(1),  rect_in_rect(1).   rect_in_circ(1),  read-
         bin(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