MATLAB-ginput函数问题

Question

MATLAB里面用ginput函数取点的时候，为什么在选第一个点的时候不显示坐标？到选择完第一点之后才出现横纵坐标？有什么办法可以解决？谢谢~

Answer 1

这个是ginput函数本身决定的

下面这个函数可以进行实时取点显示坐标 不知是否满足你的要求。
function dynpoint(arg,h)
% Show the coordinates of a plot dynamically
%
% To start use:
% dynpoint(h)
% where h is a handle to a figure, axes or e.g. line.
%
% To delete use:
% dynpoint('delete',h)
% where h is a handle to a figure, axes or e.g. line.
% (you may also use: dynpoint delete)
%
% There can only be one dynamic plotter in a figure at a time.
%
% Example:
% subplot(211), hline = plot(sin(1:10))
% subplot(212), plot(sin(1:100))
% dynpoint(hline)

% 2002,6.29

if ~exist('arg','var')
arg = gcf;
end

if ~isstr(arg)
handle = arg;
arg = 'init';
end

switch arg
case 'init'
if ~ishandle(handle)
error('h is not a handle')
end

[h,ax] = h2hax(handle);

% delete old dynamic text object
ht = findobj(h,'tag',[mfilename '_text']);
if any(ht)
delete(ht)
end

% text window at the bottom left corner
% text in centred
uicontrol(h,...
'style','text',...
'pos',[2 2 200 15],...
'tag',[mfilename '_text'],...
'userdata',ax(1))

% do the dynamic thing...
set(h,'windowbuttonmotionfcn',[mfilename ' move'])

case 'move'
ht = findobj(gcbf,'tag',[mfilename '_text']);
ax = overobj('axes');
if ~any(ax)
ax = get(ht,'userdata');
end
p = get(ax,'currentpoint');
set(ht,'string',sprintf('(%g, %g)', p(1), p(3)));

case 'delete'
if ~exist('h','var')
h = gcf;
end
[h,ax] = h2hax(h);
set(h,'windowbuttonmotionfcn','')

ht = findobj(h,'tag',[mfilename '_text']);
delete(ht)

end

% ----------
function [h,ax]=h2hax(handle)

typ = get(handle,'type');
if strcmp(typ,'figure')
h = handle;
ax = findobj(h,'type','axes');
elseif strcmp(typ, 'axes')
h = get(handle,'parent');
ax = handle;
elseif strcmp( get(get(handle,'parent'), 'type'), 'axes' )
ax = get(handle,'parent');
h = get(ax,'parent');
end本回答被提问者采纳