How to simplify this for-loop into a one line of code?

9 次查看（过去 30 天）
Leon
Leon 2025-3-12
评论： dpb 2025-3-12
Attached is a file storing a cell array A, a logical array for the columns: tf, and a logical array for A: map2.
My goal is to replace the below for-loops with a one line of code:
[m n] = size(A);
for j=1:n
for i=1:m
if ~tf(j) & map2(i,j)
A{i, j} = str2double(A{i,j});
end
end
end
Why doen't the below work?
A(~tf & map2) = str2double(A(~tf & map2));

请先登录，再回答此问题。

采纳的回答

dpb
dpb 2025-3-12
移动：dpb 2025-3-12
Ran in:
load test10
whos
Name Size Bytes Class Attributes A 8x6 6076 cell ans 1x34 68 char map2 8x6 48 logical tf 1x6 6 logical
A
A = 8x6 cell array
{'ID12' } {[ 2]} {[-25.0100]} {[ 27.7690]} {[35.5800]} {'33RC1991'} {'ID12' } {[ 2]} {[-25.0020]} {[ 25.9660]} {[35.3670]} {0x0 char } {'ID12' } {0x0 char} {[-24.9930]} {[ 25.0250]} {[35.8480]} {'200105' } {0x0 char} {0x0 char} {[-25.0010]} {[<missing>]} {0x0 char } {'456' } {'2' } {'2' } {[-25.0020]} {[ 25.3260]} {[36.0880]} {'3689' } {'2' } {'2' } {[ -25]} {[ 26.1690]} {[35.9120]} {'3256778' } {'2' } {'2' } {[ -25]} {[<missing>]} {[36.2220]} {'33RC1991'} {'ID12' } {[ 2]} {[ -25]} {[<missing>]} {[36.3660]} {'33RC1991'}
~tf & map2
ans = 8x6 logical array
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
A(~tf & map2)
ans = 3x1 cell array
{'2'} {'2'} {'2'}
try
A(~tf & map2)=str2double(A(~tf & map2))
catch ME
ME.message
A(~tf & map2)=num2cell(str2double(A(~tf & map2)))
end
ans = 'Conversion to cell from double is not possible.'
A = 8x6 cell array
{'ID12' } {[ 2]} {[-25.0100]} {[ 27.7690]} {[35.5800]} {'33RC1991'} {'ID12' } {[ 2]} {[-25.0020]} {[ 25.9660]} {[35.3670]} {0x0 char } {'ID12' } {0x0 char} {[-24.9930]} {[ 25.0250]} {[35.8480]} {'200105' } {0x0 char} {0x0 char} {[-25.0010]} {[<missing>]} {0x0 char } {'456' } {'2' } {[ 2]} {[-25.0020]} {[ 25.3260]} {[36.0880]} {'3689' } {'2' } {[ 2]} {[ -25]} {[ 26.1690]} {[35.9120]} {'3256778' } {'2' } {[ 2]} {[ -25]} {[<missing>]} {[36.2220]} {'33RC1991'} {'ID12' } {[ 2]} {[ -25]} {[<missing>]} {[36.3660]} {'33RC1991'}
You are trying to stuff a double array into a cell array -- "you can't do that!" :)
Convert the numeric array to equivalent in a cell array with num2cell.
My question is still what is wrong with the input file that caused this to happen and why not fix that instead?
  2 个评论
dpb
dpb 2025-3-12
Can you not attach the file that creates the issue for somebody to poke at and see why it fails? If it is actually a flaw in readcell it could be a good tool for Mathworks; if there's something actually in the file, perhaps the generating process could be fixed instead.

请先登录，再进行评论。

更多回答（0 个）

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

R2024b

Community Treasure Hunt

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

Start Hunting!

Translated by