建立如下所示的MATLAB函数，在生成figure图像后，在workspace中输入magnify并运行，然后在figure中左键选择出放大的区域，然后点右键确定。选择后也可以直接修改局部图像，就像修改一般的figure一样。

function magnify(f1)

%

%magnify(f1)

%

%  Figure creates a magnification box when

under the mouse

%  position when a button is pressed.

Press '+'/'-' while

%  button pressed to increase/decrease

magnification. Press

%  '>'/'

increase/decrease box size.

%  Hold 'Ctrl' while clicking to leave

magnification on figure.

%

%  Example:

%  plot(1:100,randn(1,100),(1:300)/3,rand(1,300)), grid on,

%  magnify;

% Rick Hindman - 7/29/04

if (nargin == 0), f1 = gcf; end;

set(f1, ...

'WindowButtonDownFcn',

@ButtonDownCallback, ...

'WindowButtonUpFcn',

@ButtonUpCallback, ...

'WindowButtonMotionFcn',

@ButtonMotionCallback, ...

'KeyPressFcn',

@KeyPressCallback);

return;

function ButtonDownCallback(src,eventdata)

f1 = src;

a1 =

get(f1,'CurrentAxes');

a2 =

copyobj(a1,f1);

set(f1, ...

'UserData',[f1,a1,a2], ...

'Pointer','fullcrosshair', ...

'CurrentAxes',a2);

set(a2, ...

'UserData',[2,0.2], ...  %magnification, frame

size

'Color',get(a1,'Color'), ...

'Box','on');

xlabel(''); ylabel('');

zlabel(''); title('');

set(get(a2,'Children'),

...

'LineWidth', 2);

set(a1, ...

'Color',get(a1,'Color')*0.95);

set(f1, ...

'CurrentAxes',a1);

ButtonMotionCallback(src);

return;

function ButtonUpCallback(src,eventdata)

H =

get(src,'UserData');

f1 = H(1); a1 = H(2); a2

= H(3);

set(a1, ...

'Color',get(a2,'Color'));

set(f1, ...

'UserData',[], ...

'Pointer','arrow', ...

'CurrentAxes',a1);

if

~strcmp(get(f1,'SelectionType'),'alt'),

delete(a2);

end;

return;

function ButtonMotionCallback(src,eventdata)

H =

get(src,'UserData');

if ~isempty(H)

f1 =

H(1); a1 = H(2); a2 = H(3);

a2_param = get(a2,'UserData');

f_pos

= get(f1,'Position');

a1_pos = get(a1,'Position');

[f_cp, a1_cp] = pointer2d(f1,a1);

set(a2,'Position',[(f_cp./f_pos(3:4)) 0

0]+a2_param(2)*a1_pos(3)*[-1 -1 2 2]);

a2_pos = get(a2,'Position');

set(a2,'XLim',a1_cp(1)+(1/a2_param(1))*(a2_pos(3)/a1_pos(3))*diff(get(a1,'XLim'))*[-0.5

0.5]);

set(a2,'YLim',a1_cp(2)+(1/a2_param(1))*(a2_pos(4)/a1_pos(4))*diff(get(a1,'YLim'))*[-0.5

0.5]);

end;

return;

function KeyPressCallback(src,eventdata)

H =

get(gcf,'UserData');

if ~isempty(H)

f1 =

H(1); a1 = H(2); a2 = H(3);

a2_param = get(a2,'UserData');

if

(strcmp(get(f1,'CurrentCharacter'),'+') |

strcmp(get(f1,'CurrentCharacter'),'='))

a2_param(1) =

a2_param(1)*1.2;

elseif (strcmp(get(f1,'CurrentCharacter'),'-') |

strcmp(get(f1,'CurrentCharacter'),'_'))

a2_param(1) =

a2_param(1)/1.2;

elseif (strcmp(get(f1,'CurrentCharacter'),'

strcmp(get(f1,'CurrentCharacter'),','))

a2_param(2) =

a2_param(2)/1.2;

elseif (strcmp(get(f1,'CurrentCharacter'),'>') |

strcmp(get(f1,'CurrentCharacter'),'.'))

a2_param(2) =

a2_param(2)*1.2;

end;

set(a2,'UserData',a2_param);

ButtonMotionCallback(src);

end;

return;

% Included for completeness (usually in own file)

function [fig_pointer_pos, axes_pointer_val] =

pointer2d(fig_hndl,axes_hndl)

%

%pointer2d(fig_hndl,axes_hndl)

%

% Returns the coordinates of the pointer (in pixels)

% in the desired figure (fig_hndl) and the coordinates

%  in

the desired axis (axes coordinates)

%

% Example:

%  figure(1),

%  hold on,

%  for i = 1:1000,

%  [figp,axp]=pointer2d;

%  plot(axp(1),axp(2),'.','EraseMode','none');

%  drawnow;

%  end;

%  hold off

% Rick Hindman - 4/18/01

if (nargin == 0), fig_hndl = gcf; axes_hndl = gca; end;

if (nargin == 1), axes_hndl = get(fig_hndl,'CurrentAxes');

end;

set(fig_hndl,'Units','pixels');

pointer_pos = get(0,'PointerLocation'); %pixels {0,0} lower

left

fig_pos = get(fig_hndl,'Position'); %pixels {l,b,w,h}

fig_pointer_pos = pointer_pos - fig_pos([1,2]);

set(fig_hndl,'CurrentPoint',fig_pointer_pos);

if (isempty(axes_hndl)),

axes_pointer_val = [];

elseif (nargout == 2),

axes_pointer_line = get(axes_hndl,'CurrentPoint');

axes_pointer_val = sum(axes_pointer_line)/2;

end;