loop

loop - matlab中结构域值的赋值(assignment of structure field values in loop - matlab)

我试图在循环中分配结构的字段值。

具有空值的结构声明：

result_struct = struct('a',{},'b',{},'c',{},'d',{})

我在循环中赋值如下：

% assume a, b, c, d are variables in my workspace % field names match with the variable names for index=1:n % some computation and store results in variables (a-d) result_struct(index).a = a; result_struct(index).b = b; result_struct(index).c = c; result_struct(index).d = d; end

我如何使用另一个循环将值赋给字段？ 像那样：

for fname = fieldnames(result_struct)' result_struct(index).fname = fname; % field names and variable names match end

I am trying to assign the field values of structure in loop.

Structure declaration with empty values:

result_struct = struct('a',{},'b',{},'c',{},'d',{})

I am assigning values in loop like that:

% assume a, b, c, d are variables in my workspace % field names match with the variable names for index=1:n % some computation and store results in variables (a-d) result_struct(index).a = a; result_struct(index).b = b; result_struct(index).c = c; result_struct(index).d = d; end

How can I assign the values to the fields using another loop? Like that:

for fname = fieldnames(result_struct)' result_struct(index).fname = fname; % field names and variable names match end

最满意答案

您需要使用动态字段名称来分配给结构（左手侧）。 对于右侧可以使用eval但这很危险，所以最好将变量fname保存到文件中，然后再次使用动态字段名称作为struct将其重新装入struct然后再访问fname 。

names = fieldnames(result_struct); for k = 1:numel(names) % Save variable to a file save('tmp.mat', names{k}); % Load it back into a struct tmp = load('tmp.mat', names{k}); result_struct(index).(names{k}) = tmp.(names{k}); end

或者，您可以使用save和load将整个事物转换为结构，而无需遍历字段。

fields = fieldnames(result_struct); % Save all relevant variables to a file save('tmp.mat', fields{:}); % Load it back into the result_struct result_struct(index) = orderfields(load('tmp.mat'), fields);

You need to use dynamic field names to assign to the struct (the leff-hand side). For the right hand side you could use eval but that is dangerous, so it's better to save your variable fname to a file and then load it back in as a struct prior to accessing fname, again using dynamic field names.

names = fieldnames(result_struct); for k = 1:numel(names) % Save variable to a file save('tmp.mat', names{k}); % Load it back into a struct tmp = load('tmp.mat', names{k}); result_struct(index).(names{k}) = tmp.(names{k}); end

Alternately, you can use the save and load to just transform the entire thing into a struct without having to loop through the fields.

fields = fieldnames(result_struct); % Save all relevant variables to a file save('tmp.mat', fields{:}); % Load it back into the result_struct result_struct(index) = orderfields(load('tmp.mat'), fields);