我不知道有什么办法可以做你想做的事。但有一种方法可以检查特定函数是否已被隐藏,通过变量或其他函数,使用which http://es.mathworks.com/help/matlab/ref/which.html:即分析输出which(fname, '-all')
, where fname
是包含函数名称的字符串。
采取max
以函数为例:比较(无阴影)
>> clear all
>> fname = 'max';
>> which(fname, '-all')
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@logical\max) % logical method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@char\max) % char method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@double\max) % double method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint8\max) % uint8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint16\max) % uint16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint32\max) % uint32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint64\max) % uint64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int8\max) % int8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int16\max) % int16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int32\max) % int32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int64\max) % int64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@single\max) % single method
C:\Program Files\MATLAB\R2010b\toolbox\matlab\timeseries\@timeseries\max.m % timeseries method
C:\Program Files\MATLAB\R2010b\toolbox\distcomp\parallel\@codistributed\max.m % codistributed method
C:\Program Files\MATLAB\R2010b\toolbox\shared\statslib\@ordinal\max.m % ordinal method
与(阴影)
>> fname = 'max';
>> max = 10;
>> which(fname, '-all')
max is a variable.
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@logical\max) % Shadowed logical method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@char\max) % Shadowed char method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@double\max) % Shadowed double method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint8\max) % Shadowed uint8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint16\max) % Shadowed uint16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint32\max) % Shadowed uint32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint64\max) % Shadowed uint64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int8\max) % Shadowed int8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int16\max) % Shadowed int16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int32\max) % Shadowed int32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int64\max) % Shadowed int64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@single\max) % Shadowed single method
C:\Program Files\MATLAB\R2010b\toolbox\matlab\timeseries\@timeseries\max.m % Shadowed timeseries method
C:\Program Files\MATLAB\R2010b\toolbox\distcomp\parallel\@codistributed\max.m % Shadowed codistributed method
C:\Program Files\MATLAB\R2010b\toolbox\shared\statslib\@ordinal\max.m % Shadowed ordinal method
在第二种情况下,which(fname, '-all')
告诉你max
是一个隐藏多个方法的变量。
因此,要测试是否发生阴影,
-
分配输出which(fname, '-all')
到一个变量。
原则上这可以这样做s = which(fname, '-all');
。然而不幸的是,这会产生不同的输出;特别是,% ...
上面几行中的部分(表明是否存在阴影)被删除:
>> fname = 'max';
>> s = which(fname, '-all')
s =
'variable'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@logical\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@char\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@double\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint8\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint16\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint32\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint64\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int8\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int16\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int32\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int64\max)'
'built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@single\max)'
'C:\Program Files\MATLAB\R2010b\toolbox\matlab\timeseries\@timeseries\max.m'
'C:\Program Files\MATLAB\R2010b\toolbox\distcomp\parallel\@codistributed\max.m'
'C:\Program Files\MATLAB\R2010b\toolbox\shared\statslib\@ordinal\max.m'
所以我们需要求助于evalc http://es.mathworks.com/help/matlab/ref/evalc.html获得完整的输出:s = evalc('which(fname, ''-all'')');
。结果s
是一个长字符串,包含所有行(包括% ...
部分)用换行符分隔:
>> fname = 'max';
>> s = evalc('which(fname, ''-all'')')
s =
max is a variable.
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@logical\max) % Shadowed logical method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@char\max) % Shadowed char method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@double\max) % Shadowed double method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint8\max) % Shadowed uint8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint16\max) % Shadowed uint16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint32\max) % Shadowed uint32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@uint64\max) % Shadowed uint64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int8\max) % Shadowed int8 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int16\max) % Shadowed int16 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int32\max) % Shadowed int32 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@int64\max) % Shadowed int64 method
built-in (C:\Program Files\MATLAB\R2010b\toolbox\matlab\datafun\@single\max) % Shadowed single method
C:\Program Files\MATLAB\R2010b\toolbox\matlab\timeseries\@timeseries\max.m % Shadowed timeseries method
C:\Program Files\MATLAB\R2010b\toolbox\distcomp\parallel\@codistributed\max.m % Shadowed codistributed method
C:\Program Files\MATLAB\R2010b\toolbox\shared\statslib\@ordinal\max.m % Shadowed ordinal method
分析字符串s
步骤1中获取的内容,看是否包含'% Shadowed'
。这很容易完成strfind http://es.mathworks.com/help/matlab/ref/strfind.html:即,strfind(s, '% Shadowed')
如果存在阴影,则该值将非空。
综上所述:
综合起来,
isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'));
returns true
如果函数名称包含在变量中fname
被阴影覆盖,并且false
否则。
带变量的示例:
>> clear all
>> fname = 'max';
>> max = 10;
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
1
>> clear max
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
0
具有命名函数的示例:
在文件中创建一个函数std.m
并将其放在您的路径中。这将影响 Matlab 的std
功能。
>> fname = 'std';
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
1
现在删除函数文件(或从路径中删除其文件夹):
>> fname = 'std';
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
0
匿名函数的示例:
>> std = @(x) x+1;
>> fname = 'std';
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
1
>> clear std
>> isShadowed = ~isempty(strfind(evalc('which(fname, ''-all'')'), '% Shadowed'))
isShadowed =
0