Re: LogLogPlot evaluates argument outside given range
- To: mathgroup at smc.vnet.net
- Subject: [mg103350] Re: [mg103318] LogLogPlot evaluates argument outside given range
- From: "David Park" <djmpark at comcast.net>
- Date: Wed, 16 Sep 2009 05:49:07 -0400 (EDT)
- References: <20357537.1253003699077.JavaMail.root@n11>
Most of the Plot type statements use adaptive sampling that can go outside
the designated variable domain. If there aren't other problems you could
just use Quiet.
LogLogPlot[
Interpolation[Table[10^{i, i}, {i, 1, 5}]][x] // Evaluate, {x, 10,
100000}] // Quiet
But if you really really don't want to sample outside the specified domain
you could use a ParametricPlot. ParametricPlots appear to always hit the
endpoints and to stay within the domain. In the following I use
Presentations to convert a basic ParametricPlot to a LogLog plot. This is
more work because now we have to specify the ticks and grids (but on the
other hand we get more control of them.) Also, in the ParametricDraw I use a
log10 variable for the domain because we want even sampling over the log
scale not the linear scale.
Needs["Presentations`Master`"]
f[x_] = Interpolation[Table[10^{i, i}, {i, 1, 5}]][x]
basicgraphics = ParametricDraw[{logx, f[10^logx]}, {logx, 1, 5}];
xlogticks =
CustomTicks[Log10, {1, 5, {1} // N, {2, 3, 4, 5, 6, 7, 8, 9}}];
xloggrids = CustomGridLines[Log10, {1, 5, Range[9]}, {GrayLevel[.85]}];
ylogticks =
CustomTicks[Log10, {1, 5, {1} // N, {2, 3, 4, 5, 6, 7, 8, 9}}];
yloggrids =
CustomGridLines[Log10, {1, 5, Range[9]}, {GrayLevel[.85]}];
Draw2D[
{basicgraphics /. DrawingTransform[#1 &, Log10@#2 &]},
AspectRatio -> 1,
Frame -> True,
FrameTicks -> {{ylogticks, ylogticks // NoTickLabels}, {xlogticks,
xlogticks // NoTickLabels}},
GridLines -> {xloggrids, yloggrids},
ImageSize -> 350]
The basicgraphics look like:
{{{}, {}, {Line[{{1., 10.}, {1.00123, 10.0283}, {1.00245,
10.0567}, {1.00491, 10.1136}, {1.00981, 10.2286}, {1.01963,
10.4623}, {1.03926, 10.946}, {1.07851, 11.9816}, ....,
{4.99176, 98121.2}, {4.99451, 98743.5}, {4.99588, 99056.1}, {4.99725,
99369.8}, {4.99863, 99684.4}, {5., 100000.}}]}}}
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/
From: Szabolcs Horv=E1t [mailto:szhorvat at gmail.com]
Why does LogLogPlot evaluate its argument outside the given range?
Example:
LogLogPlot[
Interpolation[Table[10^{i, i}, {i, 1, 5}]][x] // Evaluate, {x, 10,
100000}]
InterpolatingFunction::dmval: Input value {2.30277} lies outside the
range of data in the interpolating function. Extrapolation will be used.
This is bad, even if intentional, because the function passed to plot
might be written with the assumption that it will never receive
arguments outside certain bounds.