清空筛选条件
清空筛选条件

How to return corresponding entries of an array using if statement

1 次查看（过去 30 天）
University
University 2024-2-12
评论： University 2024-2-14
Please how can I handle this:
I want to use if statement such that
if intabsul == absintul && intabsur==absintur
returns the corresponding entries of the xivals and Lvals
elseif intabsul ~= absintul && intabsur~= absintur
return the corresponding entries of the xivals and Lvals
elseif intabsul == absintul && intabsur~=absintur
return the corresponding entries of the xivals and Lvals
elseif intabsul ~= absintul && intabsur==absintur
return the corresponding entries of the xivals and Lvals
else do nothing.
See my code below, although is not complete:
xivals = linspace(0, 10, 10);
Lvals = linspace(2e-8, 666.7e-6, 5);
for il=1:length(Lvals);
for ixi=1:length(xivals)
%
intul(ixi, il) = trapz(yvals, uxl(:, ixi, il));
intabsul(ixi, il) = trapz(yvals, abs(uxl(:, ixi, il)));
%
intur(ixi, il) = trapz(yvals, uxr(:, ixi, il));
intabsur(ixi,il) = trapz(yvals, abs(uxr(:, ixi, il)));
%
absintul(ixi, il) = abs(trapz(yvals, uxl(:, ixi, il)));
%
absintur(ixi,il) = abs(trapz(yvals, uxr(:, ixi, il)));
end
end

请先登录，再回答此问题。

回答（1 个）

Walter Roberson
Walter Roberson 2024-2-12
mask = intabsul == absintul & intabsur==absintur;
subset_xi_1 = xivals(mask);
subset_Lv_1 = Lvals(mask);
mask = intabsul ~= absintul & intabsur~= absintur;
subset_xi_2 = xivals(mask);
subset_Lv_2 = Lvals(mask);
and so on.
  2 个评论
University
University 2024-2-12
编辑：University 2024-2-12
Thank you so much for your help. I tried it but I received:
Error in active_flow_run (line 242)
subset_xi_1 = xivals(mask);
"The logical indices contain a true value outside of the array bounds".
Another thing is that fact : intabsul == absintul & intabsur==absintur might not be necessarily true for every entries of the matrices.
I thought of something like: intabsul-absintul < epsilon
where epsilon= 10^-11. If want to use this approach, i.e.,
if intabsul-absintul<epsilon & intabsur-absintur<epsilon
return the corresponding values of xivals and lvals
and so...
How do I handle this case?
University
University 2024-2-14
Hi Walter,
Please how can handle this error?
Error in active_flow_run (line 242)
subset_xi_1 = xivals(mask);
"The logical indices contain a true value outside of the array bounds".
I have tried several ways but I still receive this error.

请先登录，再进行评论。

类别

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

标签

产品


版本

R2023b

Community Treasure Hunt

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

Start Hunting!

Translated by