フィルターのクリア

Avoid a "loop for" to add multiple "datetime" elements to a cell array

2 ビュー (過去 30 日間)
Sim
Sim 2022 年 10 月 24 日
編集済み: dpb 2022 年 10 月 26 日
Given the matrix "a"
% (1) create the cell array / matrix "a"
a = cell(3,3);
% (2) add the first elements to the cell array / matrix "a"
index = [1 1
2 1
3 3];
b = datetime({'00:01:35'
'00:01:11'
'00:04:21'});
idx = sub2ind(size(a),index(:,1),index(:,2));
a(idx) = num2cell(b)
a = 3×3 cell array
{[24-Oct-2022 00:01:35]} {0×0 double} {0×0 double } {[24-Oct-2022 00:01:11]} {0×0 double} {0×0 double } {0×0 double } {0×0 double} {[24-Oct-2022 00:04:21]}
I would like not to use the loop for, here below, to add multiple elements to different cells:
% (3) add two new elements:
% - one new element inside the cell [2 3]
% - one new element inside the cell [3 3]
index2 = [2 3
3 3];
new_elements = datetime({'00:01:01'
'00:01:56'});
idx2 = sub2ind(size(a),index2(:,1),index2(:,2));
for i = 1 : size(idx2,1)
a{idx2(i)} = [a{idx2(i)} new_elements(i)];
end
% Desired output, but without the loop for
a,
a = 3×3 cell array
{[24-Oct-2022 00:01:35]} {0×0 double} {0×0 double } {[24-Oct-2022 00:01:11]} {0×0 double} {[24-Oct-2022 00:01:01 ]} {0×0 double } {0×0 double} {[24-Oct-2022 00:04:21 24-Oct-2022 00:01:56]}
  5 件のコメント
Sim
Sim 2022 年 10 月 26 日
thanks for your comment @dpb .... Do you have an alternative suggestion to achieve the same goal ?
dpb
dpb 2022 年 10 月 26 日
編集済み: dpb 2022 年 10 月 26 日
We don't know what "the goal" is other than the ugly-looking mess, so how can we have any suggestions about achieving same?
Is it really that your starting cell array should have been
>> N=3;
>> A=num2cell(NaT(N))
A =
3×3 cell array
{[NaT]} {[NaT]} {[NaT]}
{[NaT]} {[NaT]} {[NaT]}
{[NaT]} {[NaT]} {[NaT]}
>>
???
In that case, then at least all the elements of the cell array are datetime and you won't have the issue I raised above about having to deal with the problems of having to operate on different classes by location in the array.
But, even there I don't see a syntax without some form of a loop to do the catenation of additional elements.

サインインしてコメントする。

回答 (1 件)

Benjamin Thompson
Benjamin Thompson 2022 年 10 月 24 日
If you can make is an N by 1 cell array and do the assignment using parenthesis indexing and num2cell, then convert that to the J,K array size where J*K == N, then maybe it works for you?
b = cell(9,1);
b =
9×1 cell array
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
{0×0 double}
>> b(idx2) = num2cell(new_elements)
b =
9×1 cell array
{0×0 double }
{0×0 double }
{0×0 double }
{0×0 double }
{0×0 double }
{0×0 double }
{0×0 double }
{[24-Oct-2022 00:01:01]}
{[24-Oct-2022 00:01:56]}
  1 件のコメント
Sim
Sim 2022 年 10 月 26 日
Thanks for your answer @Benjamin Thompson, but it does not look like the same "desired output", as I indicated in my question...

サインインしてコメントする。

カテゴリ

Help Center および File ExchangeDates and Time についてさらに検索

Community Treasure Hunt

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

Start Hunting!

Translated by