How to find gradient of a vector field in matlab symbolic

25 次查看（过去 30 天）
Chandan
Chandan 2023-12-12
回答： Chandan 2023-12-13
I am trying to find gradient of a vector field in matlab symbolic , whose output will be matrix but it am getting error
  2 个评论
KSSV
KSSV 2023-12-12
Copy your code here. Don't attach it as an screen shot/ image.
Chandan
Chandan 2023-12-12
Ran in:
clc ; clear all
syms x y z
syms u(x,y,z) v(x,y,z) w(x,y,z)
V = [u v w];
S = [x y z];
gradient(u,S)
ans(x, y, z) = 
gradient(V,S) % How to take gradient of vector field
Error using sym/gradient
Invalid argument at position 1. Argument must be scalar or a symbolic function with scalar formula.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2023-12-12
移动：Walter Roberson 2023-12-12
Ran in:
The fundamental problem you are having is that gradient does not accept a vector the first parameter.
syms x y z
syms u(x,y,z) v(x,y,z) w(x,y,z)
V = [u(x,y,z) v(x,y,z) w(x,y,z)];
S = [x y z];
temp = arrayfun(@(EXPR) gradient(EXPR,S), V, 'uniform', 0);
result(x,y,z) = [temp{:}]
result(x, y, z) = 

更多回答（2 个）

Sulaymon Eshkabilov
Sulaymon Eshkabilov 2023-12-12
Ran in:
If you assign an expression for V, you will get this:
clc ; clearvars
syms x y z
syms u(x,y,z) v(x,y,z) w(x,y,z)
V(x,y,z) = 2*u+3*v-w % Some e.g. expression
V(x, y, z) = 
S = [x y z];
du = gradient(u,S)
du(x, y, z) = 
dV = gradient(V,S)
dV(x, y, z) = 
% OR simply
dV= gradient(V,[x,y,z])
dV(x, y, z) = 
Chandan
Chandan 2023-12-13
Ran in:
% thanks for answer. It worked with the Jacobian too.
clc; clearvars;
syms x y z
syms u(x, y, z) v(x, y,z) w(x,y,z)
V = [u v w];
S = [x y z];
jacobian(V,S)
ans(x, y, z) = 

类别

在 Help Center 和 File Exchange 中查找有关 Symbolic Math Toolbox 的更多信息

标签

产品


版本

R2023a

Community Treasure Hunt

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

Start Hunting!

Translated by