Undesired horizontal line in Plot / Bug?
- To: mathgroup at smc.vnet.net
- Subject: [mg118137] Undesired horizontal line in Plot / Bug?
- From: "H Hogreve" <hogreve at ifisr.org>
- Date: Thu, 14 Apr 2011 04:48:15 -0400 (EDT)
A phenomenon that occasionally also occurs in other plots can be exemplified by setting fD[n_, cZ_] := 137^2/Sqrt[1 + cZ^2/(137*n + Sqrt[137^2 - cZ^2])^2]; and plotting, e.g., Plot[{fD[1, z], fD[5, z]}, {z, 1, 137}, Frame -> True, PlotRange -> Automatic] There is a horizonal line visible (parallel to the abscissa) that should not be there!! In fact, other plots like, e.g., Plot[{fD[1, z], fD[2, z]}, {z, 1, 137}, Frame -> True, PlotRange -> Automatic] look fine, without this annoying additional line. Unfortunately, I could not find a way to remove or suppress this unwanted horizontal line in the first plot. Moreover, I observed this effect in all versions of Mathematica I have access to at the moment, i.e., four, six, and seven, and it makes me wonder whether this is a yet unresolved bug. Thus I would be very grateful for any hints on the questions - whether this horizontal line also occurs in the current Mathematica 8.0 ? - is there any remedy to prevent the line from being plotted or to remove it from the plot? Many thanks in advance for your kind help, H. Hogreve P.S.: If plotted without Frame, then this line does not occur, but apparently at its position the new abscissa is placed