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25
26## -*- texinfo -*-
27## @deftypefn  {} {} semilogx (@var{y})
28## @deftypefnx {} {} semilogx (@var{x}, @var{y})
29## @deftypefnx {} {} semilogx (@var{x}, @var{y}, @var{property}, @var{value}, @dots{})
30## @deftypefnx {} {} semilogx (@var{x}, @var{y}, @var{fmt})
31## @deftypefnx {} {} semilogx (@var{hax}, @dots{})
32## @deftypefnx {} {@var{h} =} semilogx (@dots{})
33## Produce a 2-D plot using a logarithmic scale for the x-axis.
34##
35## See the documentation of @code{plot} for a description of the
36## arguments that @code{semilogx} will accept.
37##
38## If the first argument @var{hax} is an axes handle, then plot into this axes,
39## rather than the current axes returned by @code{gca}.
40##
41## The optional return value @var{h} is a graphics handle to the created plot.
42## @seealso{plot, semilogy, loglog}
43## @end deftypefn
44
45function h = semilogx (varargin)
46
47  [hax, varargin, nargs] = __plt_get_axis_arg__ ("semilogx", varargin{:});
48
49  if (nargs < 1)
50    print_usage ();
51  endif
52
53  oldfig = [];
54  if (! isempty (hax))
55    oldfig = get (0, "currentfigure");
56  endif
57  unwind_protect
58    hax = newplot (hax);
59
60    set (hax, "xscale", "log");
61    if (! ishold ())
62      set (hax, "xminortick", "on", "box", "on");
63    endif
64
65    htmp = __plt__ ("semilogx", hax, varargin{:});
66
67  unwind_protect_cleanup
68    if (! isempty (oldfig))
69      set (0, "currentfigure", oldfig);
70    endif
71  end_unwind_protect
72
73  if (nargout > 0)
74    h = htmp;
75  endif
76
77endfunction
78
79
80%!demo
81%! clf;
82%! x = 1:0.01:10;
83%! y = (x .* (1 + rand (size (x)))) .^ 2;
84%! semilogx (y, x);
85%! title ({"semilogx() plot", "X-axis is logarithmic"});
86
87%!demo
88%! clf;
89%! x = logspace (-5, 1, 10);
90%! y = logspace (-5, 1, 10);
91%!
92%! subplot (1,2,1);
93%!  semilogx (x, y);
94%!  title ("semilogx (x, y)");
95%!
96%! subplot (1,2,2);
97%!  semilogx (-x, y);
98%!  title ("semilogx (-x, y)");
99
100%!demo
101%! clf;
102%! x = logspace (-5, 1, 10);
103%! y = logspace (-5, 1, 10);
104%!
105%! subplot (1,2,1);
106%!  semilogx (x, y);
107%!  set (gca, "xdir", "reverse", "activepositionproperty", "outerposition");
108%!  title ({"semilogx (x, y)", "xdir = reversed"});
109%!
110%! subplot (1,2,2);
111%!  semilogx (-x, y);
112%!  set (gca, "xdir", "reverse", "activepositionproperty", "outerposition");
113%!  title ({"semilogx (-x, y)", "xdir = reversed"});
114
115%!test
116%! hf = figure ("visible", "off");
117%! unwind_protect
118%!   a = logspace (-5, 1, 10);
119%!   b = logspace (-5, 1, 10);
120%!   semilogx (a, b);
121%!   assert (get (gca, "xscale"), "log");
122%!   assert (get (gca, "yscale"), "linear");
123%! unwind_protect_cleanup
124%!   close (hf);
125%! end_unwind_protect
126
127%!test
128%! hf = figure ("visible", "off");
129%! unwind_protect
130%!   a =-logspace (-5, 1, 10);
131%!   b = logspace (-5, 1, 10);
132%!   semilogx (a, b);
133%!   axis tight;
134%!   assert (all (get (gca, "xtick") < 0));
135%! unwind_protect_cleanup
136%!   close (hf);
137%! end_unwind_protect
138