Error messages.

Like any programme, atlc generates error messages. Most are pretty obvious in meaning, but you might get an error like this, which is not quite so obvious:
% atlc bad-file.bmp
Error: The colour r=0x9 g=0xff b=0x9 exists in the image, but 
the programme does not know how to interpret this colour.
This is not a conductor (pure red, green or black), nor is it
one of the 10 dielectrics that are predefined in Erdata.h,
nor is a corresponding dielectric constant defined on the command line
You may get this error if you simply try to use a different colour for another dielectric but forgot to define it. This can also happen if your graphics programme interpolates the colours in your image. For example, assume you intend drawing an elliptical conductor inside a rectangular cross section. The square grid will never fit an ellipse precisely, so the shape will look like this, which is shown on a very low-resolution image to make it more obvious
Not aliased
However, many graphics packages implement 'anti aliasing' or 'smoothing' or other such method to smooth the edges of sharp objects. Hence what your graphics package may produce is like this
For most applications, the smoother edges are preferable. However, this is not so if the bitmaps are to be read by atlc. At any sensible size of bitmap, the smoothing will not be obvious, so you may find atlc exits, when the image looks fine.
You should be aware of this problem and turn off any such smoothing functions in your graphics package. In Gimp, you should make sure that both feather and antialising are turned off (buttons up) for any tool you use. (double click on the ellipse or rectangle tools, to view or set these options)
Sometimes one makes a mistake and sets a background, (rgb=255,0,1), instead of rgb=255,0,0. However, whatever causes this message, it is a result of using a colour what atlc is not sure how to interpret.

atlc is written and supported by Dr. David Kirkby (G8WRB) It it issued under the GNU General Public License

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