Logical indexing cell array

Question

azarang asadi 2022-5-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1728650-logical-indexing-cell-array

评论： azarang asadi 2022-5-30

采纳的回答： Jan

I have a cell array as follows:

array =

5×4 cell array

{[ 0.5000]} {[ 0.0250]} {[0.4000]} {[ 0.0150]}

{[ 0.0500]} {[ 0.0300]} {[0.0600]} {[ 0.0120]}

{0×0 double} {[ 0.1500]} {[0.0500]} {[ 0.0160]}

{0×0 double} {0×0 double} {[0.0400]} {[ 0.1400]}

{0×0 double} {0×0 double} {[0.0300]} {0×0 double}

what I'm trying to identify the members<0.1 so I'm looking for the following:

array2 =

5×4 cell array

{[ 1]} {[ 0]} {[1]} {[ 0]}

{[ 0]} {[ 0]} {[0]} {[ 0]}

{0×0 double} {[ 1]} {[0]} {[ 0]}

{0×0 double} {0×0 double} {[0]} {[ 1]}

{0×0 double} {0×0 double} {[0]} {0×0 double}

and what I want finally is to get only the members that are <0.1 which is the following:

array3 =

5×4 cell array

{0×0 double} {[ 0.0250]} {0×0 double} {[ 0.0150]}

{[ 0.0500]} {[ 0.0300]} {[ 0.0600]} {[ 0.0120]}

{0×0 double} {0×0 double} {[ 0.0500]} {[ 0.0160]}

{0×0 double} {0×0 double} {[ 0.0400]} {0×0 double}

{0×0 double} {0×0 double} {[ 0.0300]} {0×0 double}

How can I do this? :)

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Image Analyst 2022-5-28

Why are you using a cell array for this? I don't see a variety of class types, nor do the cells contain variable/different sized arrays. It should be just a regular numerical array, like a double. See the FAQ:

https://matlab.fandom.com/wiki/FAQ#What_is_a_cell_array.3F

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jan 2022-5-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1728650-logical-indexing-cell-array#answer_973040

编辑：Jan 2022-5-27

在 MATLAB Online 中打开

A hint: I takes some time to create your input data such, that it can be used in an example. Please do such tedious editing by your own in future questions. Thanks.

A = {0.5000,  0.0250,  0.4000,  0.0150; ...
     0.0500,  0.0300,  0.0600,  0.0120; ...
     [] ,     0.1500,  0.0500,  0.0160; ...
     [],      [],      0.0400,  0.1400; ...
     [],      [],      0.0300,  []};
T = cellfun(@(c) any(c < 0.1), A)
T = 5×4 logical array
   0   1   0   1
   1   1   1   1
   0   0   1   1
   0   0   1   0
   0   0   1   0

Do you really need this (called "array2" in your question) as a cell array? Logical indices are fine as logical array.

Result     = A;
Result(~T) = {[]}
    {0×0 double}    {[  0.0250]}    {0×0 double}    {[  0.0150]}
    {[  0.0500]}    {[  0.0300]}    {[  0.0600]}    {[  0.0120]}
    {0×0 double}    {0×0 double}    {[  0.0500]}    {[  0.0160]}
    {0×0 double}    {0×0 double}    {[  0.0400]}    {0×0 double}
    {0×0 double}    {0×0 double}    {[  0.0300]}    {0×0 double}

What about doing this directly:

Result = cellfun(@(c) c(c < 0.1), A, 'UniformOutput', false)
    {0×0 double}    {[  0.0250]}    {0×0 double}    {[  0.0150]}
    {[  0.0500]}    {[  0.0300]}    {[  0.0600]}    {[  0.0120]}
    {0×0 double}    {0×0 double}    {[  0.0500]}    {[  0.0160]}
    {0×0 double}    {0×0 double}    {[  0.0400]}    {0×0 double}
    {0×0 double}    {0×0 double}    {[  0.0300]}    {0×0 double}

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

azarang asadi 2022-5-30

Thank you so much

请先登录，再进行评论。

Answer 2

Stephen23 2022-5-28

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1728650-logical-indexing-cell-array#answer_973115

编辑：Stephen23 2022-5-28

在 MATLAB Online 中打开

That is an inefficient way to store and process that data.

Using one numeric array would be simpler and much more efficient:

M = [0.5,0.025,0.4,0.0150;0.05,0.03,0.06,0.0120;NaN,0.15,0.05,0.0160;NaN,NaN,0.04,0.1400;NaN,NaN,0.03,NaN]
M = 5×4
    0.5000    0.0250    0.4000    0.0150
    0.0500    0.0300    0.0600    0.0120
       NaN    0.1500    0.0500    0.0160
       NaN       NaN    0.0400    0.1400
       NaN       NaN    0.0300       NaN
X = M<0.1 % simple and very efficient, unlike anything with cell arrays
X = 5×4 logical array
   0   1   0   1
   1   1   1   1
   0   0   1   1
   0   0   1   0
   0   0   1   0