semilogypn(...) is the same as SEMILOGY(...), 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.
semilogypn(X,Y) plots X versus Y as logarithmic scales, 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.
semilogypn(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,
semilogypn(X,Y,'ro-','b*') plots the positive Y with red line and 'o'
markers and the negative Y with blue stars '*'.
sets property values for all lineseries graphics objects created by
semilogypn. See the line reference page for more information.
[HP, HN] = semilogypn(...) 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] = semilogypn(x,y,'k');
set(hp, 'LineWidth', 1);
set(hn, 'LineWidth', 2);
SEMILOGY, LOGLOG, loglogpn.
Published output in the Help browser