在matlab中使用parfor

Question

我想在MATLAB中并行化我的部分代码。例如低于部分：

v1=[1,3,6,8]; 
ggx=5.*ones(15,14); 
gax=ones(15,14); 
parfor i = 1:length(v1) 
m = v1(i); 
if m > 1 
gax(1:m-1,m-1) = ggx(1:m-1,m-1); 
end 
if m<nn 
gax(m+1:end,m) = ggx(m+1:end,m); 
end 
end 

但有一个错误： 错误：在PARFOR可变GAX不能成为在MATLAB，“概述”循环classified.See并行。

有谁知道我该如何删除错误？其他有用的信息是v1是一个递增的向量，它不包含任何重复的元素。

Answer 1

正如错误消息中所述，您必须遵循Sliced Variable rule。 gax和gay都违反了Fixed Index Listing和Form of Indexing的规则。另外，您可以将此示例A(i,20:30,end) % 20:30 not scalar作为文档中未切片变量的示例。

因此，您应该更改parfor的所有部分以获得正确的并行计算。换句话说，您必须根据循环变量设计一种可以并行化该方法的适当并行算法。

Type of First-Level Indexing — The first level of indexing is either parentheses,(), or braces, {}.

Fixed Index Listing — Within the first-level parentheses or braces, the list of indices is the same for all occurrences of a given variable.

Form of Indexing — Within the list of indices for the variable, exactly one index involves the loop variable.

Shape of Array — The array maintains a constant shape. In assigning to a sliced variable, the right side of the assignment cannot be [] or '', because these operators attempt to delete elements.