# circ_in_rect

```circ_in_rect(1)             General Commands Manual            circ_in_rect(1)

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 difference
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 graphics programme), for a circular conductor inside a
rectangular 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 possible 16777216 colours can be defined
precisely by the stating 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 surrounded 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 accuracy, 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.

atlc(1), rect_cen_in_rect(1), circ_in_circ(1). rect_in_circ(1),