loglogpn(...) is the same as LOGLOG(...), except that the Y data
may have positive and negative values. This is useful to detect
unexpected negative values in the Y data (causing repeated 'Negative
data ignored' warnings), or to visualize the magnitude of an
oscillating signal in log scale.
loglogpn(X,Y) plots X versus Y in log-log scale, where Y may have
positive and negative values. By default, negative values are ploted
with dashed lines and positive values with full lines. If X is not
specified, Y is plotted versus its index.
loglogpn(X,Y,LineSpecPos,LineSpecNeg) specifies LineSpecPos and
LineSpecNeg for the line types, marker symbols and colors for the
positive and negative values of Y. For instance,
loglogpn(X,Y,'ro-','b*') plots the positive Y with red line and 'o'
markers and the negative Y with blue stars '*'. If only LineSpecPos
is specified, the same is taken for LineSpecNeg, with a different
sets property values for all lineseries graphics objects created by
loglogpn. See the line reference page for more information.
[HP, HN] = loglogpn(...) returns the handles to the two lineseries
x = linspace(1,10,200);
y = sin(x*2)./x;
axis([1 10 1e-2 1]);
[hp, hn] = loglogpn(x,y,'k');
set(hp, 'LineWidth', 1);
set(hn, 'LineWidth', 2);
LOGLOG, SEMILOGY, semilogypn.
Published output in the Help browser