Convert a datatype (like string) into Simple Plain Text like a Matlab Function

7 次查看（过去 30 天）
Umair Mughal
Umair Mughal 2020-5-10
编辑： Umair Mughal 2020-5-11
Well in programming we have datatypes that tells the compiler how to see the certain variable. And there are built-in functions imported from libraries, compiler see the whole list of functions (like sin, rand) and compile the behine the scene code.
So, if we have a string like "sin(x)", can we convert it into a simple text sin(x). So in this case instead of taking "sin(x)" as a string, compiler identifies it as a built-in function. In app Designer I want a plot a function that user can define from TextField using MATLAB programming, and the only solution I can think of this is that user can also access the MATLAB functions.
Alternatively, we can say can a user add an input as a MATLAB function, or maybe it could be like --> can we change the functions while the program running.

请先登录，再回答此问题。

采纳的回答

Ameer Hamza
Ameer Hamza 2020-5-10
编辑：Ameer Hamza 2020-5-10
See str2func(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/str2func.html to convert the string to function handle.
For more advanced cases, see feval(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/feval.html and eval(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/eval.html. However, use them with care and also read this: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval to see that why using them can be a bad idea if used carelessly:
  2 个评论
Umair Mughal
Umair Mughal 2020-5-10
编辑：Umair Mughal 2020-5-11
Well thanks, I did it with str2func(); on web I was just missing the proper words for that, and that was easy...
function main(app)
s = app.SpeedEditField.Value; % Speed of Animation
[m1, m2] = Range(app);
x = m1:0.1:m2;
try
f = str2func(strcat('@(x)', app.FunctionEditField.Value));
y = f(x);
catch ME
uialert(app.UIFigure, ME.message, 'Function Error');
return;
end
h = animatedline(app.UIAxes);
for k = 1:s:length(x)-s-1
xvec = x(k:k+(s-1));
yvec = y(k:k+(s-1));
addpoints(h, xvec, yvec);
drawnow
end
return;
end

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Startup and Shutdown 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by