How to use user input for fittype function

Question

Josiah McCarther 2016-3-16

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/273740-how-to-use-user-input-for-fittype-function

编辑： Javier Bastante 2016-3-25

I want to take user inputs for a function and in turn use it in the fittype function. I realize that the fittype uses only string values so I converted my input to a string. However it is still not working and it keeps giving me this:

Error using fittype Expected a string for the parameter name, instead the input type was 'cell'.

Here is my code:

 g=input('input your function','s')
f = fittype('g',{g});
nargs = numargs(f)
args = argnames(f)
args=sym(args)

and this is my input that I'm using for g:

a*x^2+b*exp(n*x)

Thanks

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Javier Bastante 2016-3-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/273740-how-to-use-user-input-for-fittype-function#answer_213884

在 MATLAB Online 中打开

Try this:

ft = fittype( 'a*x^2+b*exp(n*x)', 'independent', 'x', 'dependent', 'y' )

2 个评论
显示无隐藏无

Josiah McCarther 2016-3-24

Thanks for the response, but I don't think this is exactly what I'm looking for. I want to be able to read out the variables of a function based on user input instead of typing the equation directly into the code.

Javier Bastante 2016-3-25

编辑：Javier Bastante 2016-3-25

在 MATLAB Online 中打开

well you are right, but then use this:

g=input('Input your function: ','s');
ft = fittype( g, 'independent', 'x', 'dependent', 'y' )

and then introduce your input function, a*x^2+b*exp(n*x), or whatever.

I use this way, what I saw on your code us that you introduced {g} as input argument, and that's why MATLAB says that you are introducing a cell because {} are used for cell variables. I hope it works this time. Regards

请先登录，再进行评论。