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