function L = barbs(varargin);
% Plots vector fields and vector time series
%
% DESCRIPTION:
% Plots barbs or arrows conserving angles and can place a scaling bar.
% The positions of the components u and v can be entered as matrices
% or vectors as with quiver.m
% The x axes can be labels of datestr.m
% A scaling factor (dar) is used between the x axes and y axes
% to conserve the angles and another scaling factor (ra) is
% used for the length of the barbs ir arrows.
%
% INPUT VARIABLES:
% u,v = Vector Componentes
% t,p = Positions of the vectors u,v
% t is usually a time series but can also be x coordinates
% p is usually vertical coordinates
% ft = datestr.m format for labeling the the x axes
% dar = Scaling factor between x and y axes
% This is set as the second element of the property 'DataAspectRatio'
% ra = Length scaling factor for the barbs or arrows
% s = Type of line or 'LineStyle'
% lim = Limits for the axes in the form [xmin,xmax] or
% [xmin,xmax,ymin,ymax]
% rv = Magnitude of the scaling bar
% units = Units of the barbs as a string
% dx,dy = Normalized position of the scaling bar
%
% OUTPUT VARIABLES:
% L = Vector of handles of the lines, L(end) is the handle of the
% scaling bar if it exist
%
% DEFAULT INPUT VARIABLES:
% The default values change depending on the input format
% t = 1:length(u), dar = 1, ra = 1, s = 'b', ft=6, y p=0:10:10*size(u,2)
% rv y units are omitded if values are not given
%
% VALID INPUT FORMATS:
% Number of | Posible
% Arguments | Formats
%--------------------------------------------------------------------------
% <2 | Runs the barbs demo
% 2 | (u,v)
% 3 | (u,v,dar)
% 4 | (u,v,t,p), (u,v,t,ft), (u,v,dar,ra)
% 5 | (u,v,t,p,ft), (u,v,t,ft,dar), (u,v,t,ft,s), (u,v,dar,ra,s)
% 6 | (u,v,t,p,ft,dar), (u,v,t,ft,dar,ra), (u,v,t,ft,dar,s), (u,v,dar,ra,s,lim)
% 7 | (u,v,t,p,ft,dar,ra), (u,v,t,ft,dar,ra,s), (u,v,t,ft,dar,ra,rv)
% | (u,v,t,ft,dar,ra,lim)
% 8 | (u,v,t,p,ft,dar,ra,s), (u,v,t,ft,dar,ra,s,lim), (u,v,dar,ra,s,lim,rv,units)
% | (u,v,t,ft,dar,ra,rv,units)
% 9 | (u,v,t,p,ft,dar,ra,s,lim), (u,v,t,ft,dar,ra,s,lim,rv)
% 10 | (u,v,t,p,ft,dar,ra,s,lim,rv), (u,v,t,ft,dar,ra,s,lim,rv,units)
% | (u,v,dar,ra,s,lim,rv,units,dx,dy)
% 11 | (u,v,t,p,ft,dar,ra,s,lim,rv,units),
% 12 | (u,v,t,ft,dar,ra,s,lim,rv,units,dx,dy)
% 13 | (u,v,t,p,ft,dar,ra,s,lim,rv,units,dx,dy)
%
% Notes:
% If u and v are vectors, it does not matter if they are
% column vectors or row vectors.
% If u, v, t and p are matrices, the variables should be
% used as if using quiver.m.
% If u and v are matrices and t and p are vectors, u and v
% are separated in length(t) rows amd length(p) columns.
% For example if t and p are set as:
% t=-2:.2:2; p=-1:.15:1;
% this is equivalent to using:
% [t,p] = meshgrid(t,p);
% but u and v must correspond in dimensions to t and p
% as if using quiver.m (see Examples 5 and 6 in demo).
% If datestr.m labels are not wanted ft can be set as [].
% If any marker is used for the 'LineStyle', arrows are drawn
% instead of barbs (lines).
% At the end of the program is a demo which can be reviewed
% for further details.
% The demo is run by executing the program with <2 input variables.
%
% Comments:
% The section where the input variables are read could be
% made more efficient by using a switch for every number
% of arguments and then using if's to determine the proper
% format but I'm to lazy to change it because
% the program works fine the way it is.
% If someone is up to it be my guest.
% The only reason I opted to use try's is because it
% was faster for me to program because in a sense I programed
% all formats at once.
% Oh, and sorry the comments are in spanish...
%
%Copy-Left, Alejandro Snchez-Barba, 2005
if ~ishold
newplot;
end
if length(varargin)<2
barbsdemo
return
end
[u,v,t,p,ft,dar,ra,st,co,mark, ...
lim,rv,units,dx,dy] = parseinputs(varargin);
%****** IMPORTANT *******
%Scale correction for u
u = u./dar;
%Draw a barb
if isempty(mark) | strcmpi(mark,'o') %default
astilla = [0; 1; NaN];
dim = 3;
elseif strcmpi(mark,'*')
astilla = [0; 1; 0.8; 1; 0.8; NaN] ...
+ [0; 0; 0.07; 0; -0.07; NaN]*i;
dim = 6;
end %if
LL = []; %handle
%If parameters are given in quiver format
if size(t)==size(p) & size(u)==size(t)
u = u(:);
v = v(:);
t = t(:)';
p = p(:)';
try
if ~isempty(lim)
if length(lim)==2
ind = (t>=lim(1) & t<=lim(2));
elseif length(lim)==4
ind = (t>=lim(1) & t<=lim(2) & p>=lim(3) & p<=lim(4));
else
error('Invalid Lim')
end %if
t = t(ind);
u = u(ind);
v = v(ind);
p = p(ind);
end %if
end %try
z = (u + v*i).';
a = ra*astilla*z + ones(dim,1)*t + ones(dim,1)*p*i;
LL = plot(a(:),[co,st],'clipping','off');
if strcmpi(mark,'o')
b = [0.8; 1; 0.8; 0.85] + [0.07; 0; -0.07; 0]*i;
dim = 4;
a = ra*b*z + ones(dim,1)*t + ones(dim,1)*p*i;
LL = [LL; patch(real(a),imag(a),co,'edgecolor','none')];
end
else
%Encuentra los valores fuera del eje en las x y las y, y los elimina
if ~isempty(lim)
try
ind = find(t>=lim(1) & t<=lim(2));
t = t(ind);
u = u(ind,:);
v = v(ind,:);
in = find(p>=lim(3) & p<=lim(4));
catch
in = 1:size(u,2);
end %try
else
in = 1:size(u,2);
end %if
for j=in(1):in(end)
z = (u(:,j) + v(:,j)*i).';
a = ra*astilla*z + ones(dim,1)*t(:)' + p(j)*i;
aj(:,j) = a(:);
end %for
LL = plot(aj,[co,st],'clipping','off');
end
%Correct axis limits
if ~isempty(lim)
if length(lim)==2
set(gca,'xlim',[lim(1), lim(2)])
elseif length(lim)==4
axis([lim(1), lim(2), lim(3), lim(4)])
else
error('Invalid Lim')
end %if
elseif all(size(t)==1)
set(gca,'xlim',[t(1), t(end)])
end %if
set(gca,'DataAspectRatio',[1, dar, 1], ...
'PlotboxAspectRatio',[1, dar, 1]);
if length(t)~=length(p) | length(u)~=length(t)
set(gca,'ytick',[])
end
%Since the default value for t starts with 1
if t(1)~=1 & ~isempty(ft)
tcks = get(gca,'xtick');
tk = datestr(tcks,ft);
set(gca,'xTickLabel',tk)
end %if
%Scale Bar
if ~isempty(rv)
yval = get(gca,'ylim');
xval = get(gca,'xlim');
ydist = abs(yval(2)-yval(1));
xdist = abs(xval(2)-xval(1));
px = xval(1) + dx*xdist;
py = yval(1) + dy*ydist;
grad = px + py.*i;
%para poner la escala por debajo de units cambiar a:
%ra*[0; 1]*rv/dar + ones(2,1)*grad;
Legend = ones(2,1)*grad - ra*[0; 1]*rv/dar;
LL = [LL; line(real(Legend),imag(Legend), ...
'color',co,'LineStyle',st',...
'clipping','off','linewidth',1)];
txt = sprintf('%g %s',rv,units);
LL = [LL; text(px,py,txt,'verticalAlign','bottom', ...
'horizontalalign','left')];
end
box on
if nargout==1
L = LL;
end
%-----------------------------------------------------------------
function barbsdemo
%demo of barbs
close all
%Example 1
u = linspace(0,-5,30);
v = linspace(-5,5,30);
dar = 1;
ra = 1;
figure
subplot(2,2,1)
feather(u,v);
title('feather')
%Example 2:
subplot(2,2,2)
h = barbs(u,v);
title('barbs')
%It can be seen clearly that feather does
%not conserve the angles but barbs does a good job
%Example 3:
[x,y] = meshgrid(-3:.2:3);
z = peaks(x,y);
%z = x.*exp(-y.^2 - y.^2);
[u,v] = gradient(z,.2,.2);
subplot(2,2,3)
quiver(x,y,u,v)
title('quiver')
%Example 4:
subplot(2,2,4)
%The values for dar and ra can be calculated
%by trial and error
dar = 1;
ra = 0.02;
s = '-b*';
barbs(u,v,x,y,[],dar,ra,s)
title('barbs')
%Example 5:
%This is the first mode of barbs
%Here, t and p represent time and depths
u = randn(100,5)+1;
v = randn(100,5)-1;
t = linspace(datenum(2003,1,1),datenum(2003,1,30),100);
p = linspace(0,-15,5);
dar = 1.1;
ra = 1;
ft = 6;
s = '-b';
lim = [datenum(2003,1,5),datenum(2003,1,20)];
rv = 2;
units = 'm/s';
dx = 0.8;
dy = 0.02;
figure
subplot(2,2,1)
h = barbs(u,v,t,p,ft,dar,ra,s,lim,rv,units,dx,dy);
ylabel('Depth (m)')
xlabel('Time (mm/dd)')
title('Mode 1')
%Example 6:
%This is the other mode of barbs
%This mode is equivalent to using quiver
[t,p] = meshgrid(t,p);
u = flipdim(rot90(u),1);
v = flipdim(rot90(v),1);
subplot(2,2,2)
barbs(u,v,t,p,ft,dar,ra,s,lim,rv,units,dx,dy)
xlabel('Time(mm/dd)')
title('Mode 2')
%Example 7:
t = linspace(-116,-104,100);
t = [t; t; t; t; t];
p = linspace(23,30,100);
p = [p+8; flipdim(p,2)+4; p+4; flipdim(p,2); p];
subplot(2,2,3)
quiver(t,p,u,v)
title('quiver')
axis([-118,-102, 22,40]);
%Example 8:
s = '-b*';
dx = 0.3;
dy = 0.8;
ra = 0.5;
units = 'esf';
lim = [-118,-102, 22,40];
subplot(2,2,4)
barbs(u,v,t,p,[],dar,ra,s,lim,rv,units,dx,dy)
ylabel('Latitude')
xlabel('Longitude')
title('barbs')
%grid on
figure
%Now the vectors and positions are given as vectors
u = reshape(u,500,1);
v = reshape(v,500,1);
t = reshape(t,500,1);
p = reshape(p,500,1);
s = '-bo';
dx = 0.3;
dy = 0.8;
dar = 1.1;
ra = 0.5;
rv = 2;
units = 'm/s';
lim = [-118,-102, 22,40];
barbs(u,v,t,p,[],dar,ra,s,[],rv,units,dx,dy)
return
%--------------------------------------------------------------------
function [u,v,t,p,ft,dar,ra,st,co,mark, ...
lim,rv,units,dx,dy] = parseinputs(a)
u = a{1};
v = a{2};
if prod(size(u))~=prod(size(v))
error('u & v have to be the same length');
end
if any(size(u)==1)
u=u(:); v=v(:);
end
%Initialize
t = []; p = []; ft = [];
dar = []; ra = []; s = [];
lim = []; rv = []; units = [];
dx = []; dy = [];
try %1
if length(a{3})>1
t = a{3};
else
dar = a{3};
end
try %2
if all(size(a{4})==1) & ~isempty(t)
ft = a{4};
elseif any(size(a{4})>1)
p = a{4};
else
ra = a{4};
end
try %3
if isempty(ft) & isnumeric(a{5}) | isempty(a{5})
ft = a{5};
elseif isnumeric(a{5}) & isempty(dar)
dar = a{5};
else
s = a{5};
end
try %4
if isempty(dar) & isnumeric(a{6})
dar = a{6};
elseif isnumeric(a{6}) & length(a{6})==1
ra = a{6};
elseif isstr(a{6})
s = a{6};
else
lim = a{6};
end
try %5
if isempty(ra)
ra = a{7};
elseif isstr(a{7})
s = a{7};
elseif length(a{7})==1
rv = a{7};
else
lim = a{7};
end
try %6
if isempty(s) & isstr(a{8})
s = a{8};
elseif isstr(a{8})
units=a{8};
else
lim = a{8};
end
try %7
if isempty(lim)
lim = a{9};
elseif ~isempty(t)
rv = a{9};
else
dx = a{9};
end
try %8
if isempty(rv)
rv=a{10};
elseif isstr(a{10})
units=a{10};
else
dy = a{10};
end %if
try %9
if isempty(units)
units=a{11};
else
dx = a{11};
end %if
try %10
if isempty(dx)
dx = a{12};
else
dy = a{12};
end %if
try %11
dy = a{13};
%11 end's
end,end,end,end,end,
end,end,end,end,end,end
%default values
if isempty(t)
t = 1:size(u,1);
end
if isempty(dar)
dar = 1;
end
if isempty(ra)
ra = 1;
end
if isempty(s)
s = 'b';
end
if isempty(p)
p = 0:10:10*(size(u,2)-1);
end
[st,co,mark,msg] = colstyle(s);
error(msg)
if isempty(co),
co = get(gca,'colororder');
co = co(1,:);
end %if
if isempty(st);
st = '-';
end
if ~isempty(rv)
if isempty(units)
units = 'm/s';
end
if isempty(dx)
dx = 0.3;
end
if isempty(dy)
dy = 0.8;
end
end
return
