a small question of the sym

3 次查看（过去 30 天）
xingyu
xingyu 2011-4-1
Hi I don't know how to get the numerical number after define sym. a simple code is shown as follows, how to get the value of m when x=1? Thanks
syms x n=sin(x^2); m=diff(n,x);

请先登录，再回答此问题。

采纳的回答

Sean de Wolski
Sean de Wolski 2011-4-1
double(m)
Edit:
You'll need to use subs to fill in the value:
subs(m,'x',1)

更多回答（1 个）

xingyu
xingyu 2011-4-1
But there is something wrong. do you mean:
x=1; n=double(n); m=double(m);
but it doesn't work
  1 个评论
Walter Roberson
Walter Roberson 2011-4-1
x = 1; double(subs(n))
OR
double(subs(n,x,1)) %without assigning to x

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Conversion Between Symbolic and Numeric 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