find all anonymous function in a workspace
显示 更早的评论
There surely has to be a way of doing this: finding all anonymous functions in a specified workspace.
Presumably the solution involves using `whos` but I can't find it on web.
For a specific example suppose my workspace has the following variables
f = @x) x^2 ;
g = @(z,y) x^3 + z;
a = rand(5,3);
b = a^3 + 5;
I want a command that will identify (and return) f and g. A bonus would be for the command to list the arguments of f and g, but I can live without that.
Thanks for any suggestions.
2 个评论
Steven Lord
2021-12-17
What's your application? Why are you trying to do this / how would you use this information?
If you're trying to generate a list of possible objective functions to pass into an optimization function, an ODE solver, an integration function, etc. know that some of those functions may accept objects that have an feval method as their "function" input. So you may not be generating all the possible values available for use in that function.
Leo Simon
2021-12-17
采纳的回答
Walter Roberson
2021-12-17
Borrowing heavily from @Benjamin
f = @(x) x^2 ;
g = @(z,y) y^3 + z;
h = @sin; % This is NOT an anonymous function!!!!
a = rand(5,3);
b = a.^3 + 5;
S = whos();
names = {S.name};
classes = {S.class};
function_handle_names = names(strcmp(classes,'function_handle'))
info = cellfun(@(S) functions(evalin('caller', S)), function_handle_names, 'uniform', 0);
issimple = strcmp(cellfun(@(S)S.type, info, 'uniform', 0), 'simple');
anonymous_functions = function_handle_names(~issimple)
6 个评论
Walter Roberson
2021-12-17
func2str() can return the text of an anonymous function, and from there you can parse out the @(...) part to get the parameter list
Stephen23
2021-12-17
@Walter Roberson: isn't that text is already available in info.function ?
Leo Simon
2021-12-17
I do not see it?
f = @(x) x^2 ;
g = @(z,y) y^3 + z;
h = @sin; % This is NOT an anonymous function!!!!
a = rand(5,3);
b = a.^3 + 5;
S = whos();
names = {S.name};
classes = {S.class};
function_handle_names = names(strcmp(classes,'function_handle'))
info = cellfun(@(S) functions(evalin('caller', S)), function_handle_names, 'uniform', 0);
issimple = strcmp(cellfun(@(S)S.type, info, 'uniform', 0), 'simple');
anonymous_functions = function_handle_names(~issimple)
Not here, and not on my desktop machine.
Remember that it is extracting information from whos() and the anonymous functions I create for info and issimple are not done until after whos() is run, so curly would have had to have been in your workspace already for it to show up.
I do not see it?
f = @(x) x^2 ;
g = @(z,y) y^3 + z;
h = @sin; % This is NOT an anonymous function!!!!
a = rand(5,3);
b = a.^3 + 5;
S = whos();
names = {S.name};
classes = {S.class};
function_handle_names = names(strcmp(classes,'function_handle'))
info = cellfun(@(S) functions(evalin('caller', S)), function_handle_names, 'uniform', 0);
issimple = strcmp(cellfun(@(S)S.type, info, 'uniform', 0), 'simple');
anonymous_functions = function_handle_names(~issimple)
Not here, and not on my desktop machine.
Remember that it is extracting information from whos() and the anonymous functions I create for info and issimple are not done until after whos() is run, so curly would have had to have been in your workspace already for it to show up.
Leo Simon
2021-12-17
更多回答（1 个）
% set up some variables in the workspace:
f = @(x) x^2 ;
g = @(z,y) y^3 + z;
a = rand(5,3);
b = a.^3 + 5;
S = whos();
names = {S.name};
classes = {S.class};
function_handle_names = names(strcmp(classes,'function_handle'));
display(function_handle_names);
2 个评论
This finds all function handles, not anonymous functions as the question requests.
f = @(x) x^2 ;
g = @(z,y) y^3 + z;
h = @sin; % This is NOT an anonymous function!!!!
a = rand(5,3);
b = a.^3 + 5;
S = whos();
names = {S.name};
classes = {S.class};
function_handle_names = names(strcmp(classes,'function_handle'));
display(function_handle_names);
Voss
2021-12-17
That's a good point.
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