convert string to equation

32 次查看（过去 30 天）
Abdullah Azzam
Abdullah Azzam 2021-3-31
评论： per isakson 2021-3-31
Hi guys I am building an application using the app designer. However, I have ran into issue because I want the user to feed his equation into the app. However, the edited field can either be numaric or text so if fore example user want to input an equation (5*x^2) how would that be done? I have tried using string field and use str2double and str2num but that didn't work any thoughts on that?

请先登录，再回答此问题。

回答（1 个）

per isakson
per isakson 2021-3-31
编辑：per isakson 2021-3-31
Or a smelling solution if you don't have the symbolic toolbox
>> x=3;
>> v = eval('(5*x^2)')
v =
45
>>
Create an anonymous function
>> foo = eval(['@(x)','(5*x^2)'])
foo =
function_handle with value:
@(x)(5*x^2)
>> foo(2)
ans =
20
>>
  2 个评论
Stephen23
Stephen23 2021-3-31
编辑：Stephen23 2021-3-31
Ran in:
str = '5*x^2';
foo = str2func(sprintf('@(x)%s',str));
foo(2)
ans = 20

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Develop Apps Using App Designer 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