Add field to a double array?

2 次查看（过去 30 天）
Shuangjun
Shuangjun 2017-10-12
编辑： Shuangjun 2017-10-12
I am working on a released code and ran into a wield error. Cited here:
...
warning('off','MATLAB:warn_r14_stucture_assignment');
obj.mu.static = obj.mu(remDim)-obj.sigma(remDim,dim)*inv(obj.sigma(dim,dim))*obj.mu(dim);
obj.mu.dynamic = obj.sigma(remDim,dim)*inv(obj.sigma(dim,dim));
warning('on','MATLAB:warn_r14_stucture_assignment');
...
Notice on second line. obj.mu is a 6x1 double array. So obj.mu(remDim) makes sense. However, how can this one be assigned to obj.mu.static as the 6x1 array can't have field.
Is that valid on old version of matlab? Can anyone explain what structure is this? What is the exact purpose of such structure.

请先登录，再回答此问题。

采纳的回答

Steven Lord
Steven Lord 2017-10-12
Someone decided to ignore our warning about this behavior in the release R14SP2 Release Notes, even though we state that "In a future release of MATLAB, attempting this type of operation will throw an error instead of just displaying a warning message." That behavior became an error in release R2015b.

更多回答（1 个）

OCDER
OCDER 2017-10-12
My best guess is that someone is trying to restructure obj.mu that had a double array into one that has two fields instead. It's more of a quick fix when someone built a huge code with obj.mu = double array, but later realized it should be obj.mu.static and obj.mu.dynamic.
See comments to understand what the programmer might be thinking (but you'll have to contact the programmer to know for sure):
obj.mu = 1:6; %Oh, never mind. I should change this.....
warning('off','MATLAB:warn_r14_stucture_assignment'); %I know this will give a warning, so suppress
obj.mu.static = obj.mu(remDim)-obj.sigma(remDim,dim)*inv(obj.sigma(dim,dim))*obj.mu(dim); %override double array with "static" field
obj.mu.dynamic = obj.sigma(remDim,dim)*inv(obj.sigma(dim,dim)); %make new "dynamic" field under mu
warning('on','MATLAB:warn_r14_stucture_assignment'); %disable suppression
  1 个评论
Shuangjun
Shuangjun 2017-10-12
Thank you for the reasoning. As Steven mentioned, it seems to be a warning operation in the old version matlab. Indeed strange structure, double array with own field...

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Programming 的更多信息

标签

产品

Community Treasure Hunt

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

Start Hunting!

Translated by