该函数调用格式为：

[ax,hl1,hl2] = plotxx(x1,y1,x2,y2,xlabels,ylabels);

参数说明：

ax是坐标轴的句柄。h1 和 h2 是两条曲线的句柄。x1,y1,x2,y2

是绘图数据。Xlabels，Ylabels是X轴和Y州标注内容对应的细胞结构。

例：

D = linspace(-100,0,50);%Y轴数据

S = linspace(34,32,50);%上侧X轴数据

T = 10*exp(D/40);%下侧X轴数据

xlabels{1} = 'Temperature (C)';%下侧X轴内容标注

xlabels{2} = 'Salinity';%上侧X轴内容标注

ylabels{1} = 'Depth(m)';%左侧Y轴内容标注

ylabels{2} = 'Depth(m)';%右侧Y轴内容标注

[ax,hlT,hlS] = plotxx(T,D,S,D,xlabels,ylabels);%绘制双X轴曲线

附件：plotxx.m

function [ax,hl1,hl2] = plotxx(x1,y1,x2,y2,xlabels,ylabels);

%PLOTXX - Create graphs with x axes on both top and

bottom %

%Similar to PLOTYY, but ...

%the independent variable is on the y-axis, %and both dependent variables are on the x-axis.

%

%Syntax: [ax,hl1,hl2] = plotxx(x1,y1,x2,y2,xlabels,ylabels);

%

%Inputs: X1,Y1 are the data for the first line (black)

% X2,Y2 are the data for the second line (red)

% XLABELS is a cell array containing the two x-labels

% YLABELS is a cell array containing the two y-labels

%

%The optional output handle graphics objects AX,HL1,HL2

%allow the user to easily change the properties of the plot.

%

%Example: Plot temperature T and salinity S % as a function of depth D in the ocean

%

%D = linspace(-100,0,50);

%S = linspace(34,32,50);

%T = 10*exp(D/40);

%xlabels{1} = 'Temperature (C)';

%xlabels{2} = 'Salinity';

%ylabels{1} = 'Depth(m)';

%ylabels{2} = 'Depth(m)';

%[ax,hlT,hlS] = plotxx(T,D,S,D,xlabels,ylabels);

%The code is inspired from page 10-26 (Multiaxis axes)

%of the manual USING MATLAB GRAPHICS, version 5.

%

%Tested with Matlab 5.3.1 and above on PCWIN

%Author: Denis Gilbert, Ph.D., physical oceanography

%Maurice Lamontagne Institute, Dept. of Fisheries and Oceans

Canada

%email: Web: http://www.qc.dfo-mpo.gc.ca/iml/

%November 1997; Last revision: 01-Nov-2001

if nargin < 4

error('Not enough input

arguments')

elseif nargin==4

%Use empty strings for the

xlabels

xlabels{1}=' '; xlabels{2}='

'; ylabels{1}=' '; ylabels{2}=' ';

elseif nargin==5

%Use empty strings for the

ylabel

ylabels{1}=' '; ylabels{2}='

';

elseif nargin > 6

error('Too many input

arguments')

end

if length(ylabels) == 1

ylabels{2} = ' ';

end

if ~iscellstr(xlabels) error('Input xlabels must be a

cell array')

elseif ~iscellstr(ylabels) error('Input ylabels must be a

cell array')

end

hl1=line(x1,y1,'Color','k');

ax(1)=gca;

set(ax(1),'Position',[0.12 0.12 0.75 0.70])

set(ax(1),'XColor','k','YColor','k');

ax(2)=axes('Position',get(ax(1),'Position'),...

'XAxisLocation','top',...

'YAxisLocation','right',...

'Color','none',...

'XColor','r','YColor','k');

set(ax,'box','off')

hl2=line(x2,y2,'Color','r','Parent',ax(2));

%label the two x-axes

set(get(ax(1),'xlabel'),'string',xlabels{1})

set(get(ax(2),'xlabel'),'string',xlabels{2})

set(get(ax(1),'ylabel'),'string',ylabels{1})

set(get(ax(2),'ylabel'),'string',ylabels{2})

【转载】http://hi.baidu.com/hyyly520/blog/item/21cb2e2260ea3349ad34de07.html