Calculate the gradient of a function
조회 수: 60 (최근 30일)
이전 댓글 표시
Hello. I want to calculate the gradient of the function :
g={@(x)-x;@(x)x-1;@(y)-y;@(y)y-1};
with the following command :
gradient(g, [x, y]);
but I get the following error :
Undefined function or variable 'x'.
How I should proceed? Thanks.
댓글 수: 2
채택된 답변
Walter Roberson
2016년 9월 13일
You are confusing the numeric gradient function http://www.mathworks.com/help/matlab/ref/gradient.html with the symbolic gradient function, http://www.mathworks.com/help/symbolic/gradient.html
On the other hand, neither gradient() accepts a vector or cell array of function handles. Numeric gradient() accepts a numeric vector or array, and spacing distances for each of the dimensions. Symbolic gradient() accepts a scalar symbolic expression or symbolic function together with the variables to take the gradient over.
When you have a vector of functions to work with, you almost certainly want a jacobian rather than a gradient. Symbolic jacobian http://www.mathworks.com/help/symbolic/jacobian.html accepts a symbolic expression, symbolic function, or symbolic vector (but not a cell array of function handles.)
댓글 수: 3
추가 답변 (1개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Linear Algebra에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!