Documentation of pncont

Global Index (all files) (short | long) | Local Index (files in subdir) (short | long)

Function Synopsis

[h, c] = pncont(xa, ya, x, clev, lab, s);

Help text

     [h, c] = pncont(xa, ya, x, clev, lab, s);

     This function will plot positive contours of x in solid
     lines, and negative contours of x in dashed lines.

     pncont(x) pncont's the matrix 'x'.
     pncont(xa, ya, x) uses xa and ya as the x and y axes resp.
     pncont(xa, ya, x, clev) uses levels outlined in 'clev', or if
                             clev is an integer, uses clev levels.
     pncont(xa, ya, x, clev, lab) lab = 0 => don't label contours (default)
                                  lab = 1 => label contours

     pncont(xa, ya, x, clev, lab, s) s is a string containing the
                                     various plotting conventions.
                                     e.g. s = ['--k'] or whatever.

Cross-Reference Information

Listing of function pncont

function [h, c] = pncont(xa, ya, x, clev, lab, s);

%cla
nexta = lower(get(gca, 'NextPlot'));
nextf = lower(get(gcf, 'NextPlot'));

hold_state = strcmp(nexta, 'add') & strcmp(nextf, 'add');
if ~hold_state; cla; end;

lw = 1;

if nargin == 1;
  x = xa;
  [m, n] = size(x);
  xa = 1:n;
  ya = 1:m;
end;
if nargin < 4; clev = 10; end;
if nargin < 5; lab = 0; end;
if nargin < 6;
  if nargin == 5
    if isstr(lab);
      s = lab; lab = 0;
    else
      lab = s; s = [];
    end
  else
    s = [];
  end
end

if isscalar(clev);
  minx = min(min(x));
  maxx = max(max(x));
  cint = (maxx - minx + 2*eps) / clev;
  clev = (minx+eps):cint:(maxx+eps);
end

[m,n] = size(x);

xp = eps * ones(m,n);
xn = -1 * eps * ones(m,n);
for i = 1:m;
  for j = 1:n;
    if x(i,j) <= 0;
      xp(i,j) = 0;
      xn(i,j) = x(i,j);
    else;
      xp(i,j) = x(i,j);
      xn(i,j) = 0;
    end;
  end;
end;
hold on
h = []; c = [];
if (max(max(x)) > clev(find(clev == min(clev(find(clev > 0))))))
  [a, b] = contour(xa, ya, xp, clev(find(clev)), ['-' s]);
  if lab; clabel(a, b, 'manual'); end;
  set(b,'linewidth',lw);
  h = [b];
  c = [a];
end;
if (min(min(x)) < clev(find(clev == max(clev(find(clev < 0))))));
  [cc, d] = contour(xa, ya, xn, clev(find(clev)), ['--' s]);
  if lab; clabel(c, d, 'manual'); end;
  set(d,'linewidth',lw);
  h = [h; d];
  c = [c cc];
end;
if (max(max(x)) > 0) & (min(min(x)) < 0 & ismember(0,clev) )
  [e, f] = contour(xa, ya, x, [0 0], ['-' s]);
  if lab; clabel(e, f, 'manual'); end;
  set(f,'linewidth',2*lw);
  h = [h; f];
  c = [c e];
end;
hold off
grid on;