how to do for loop 2nd level?

hi guys, i want to do :

XY :

AA

AB

AC

AD

..

QQ

but this error happened.

[Arif]

Here is my code

clc

clear

beam = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'}

column = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'}

for i = 1 : length(beam)

x(i) = string(beam(i))

for j = 1 : length(column)

y(j) = string(column(j))

xy(i) = append(x(i),y(j))

end

Answer 1

[Rik]

Your code can be optimized, but here are the minimal changes.

beam = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'};
column = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'};
xy=repmat("",numel(beam)*numel(column),1);
k=0;
for i = 1 : numel(beam)
    x = string(beam(i));
    for j = 1 : numel(column)
        y = string(column(j));
        k=k+1;
        xy(k) = x+y;
    end
end
xy

xy = 289×1 string array
    "AA"
    "AB"
    "AC"
    "AD"
    "AE"
    "AF"
    "AG"
    "AH"
    "AI"
    "AJ"
    "AK"
    "AL"
    "AM"
    "AN"
    "AO"
    "AP"
    "AQ"
    "BA"
    "BB"
    "BC"
    "BD"
    "BE"
    "BF"
    "BG"
    "BH"
    "BI"
    "BJ"
    "BK"
    "BL"
    "BM"

Now for the more compact version (using implicit expansion and transposing with .'):

beam = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'};
column = {'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';'K';'L';'M';'N';'O';'P';'Q'};
xy = string(beam).'+string(column);
xy = xy(:);
xy

xy = 289×1 string array
    "AA"
    "AB"
    "AC"
    "AD"
    "AE"
    "AF"
    "AG"
    "AH"
    "AI"
    "AJ"
    "AK"
    "AL"
    "AM"
    "AN"
    "AO"
    "AP"
    "AQ"
    "BA"
    "BB"
    "BC"
    "BD"
    "BE"
    "BF"
    "BG"
    "BH"
    "BI"
    "BJ"
    "BK"
    "BL"
    "BM"

Or perhaps even this:

beam = string(num2cell('A':'Q'));
column = string(num2cell('A':'Q'));
xy = reshape(beam+column.',[],1);
xy

xy = 289×1 string array
    "AA"
    "AB"
    "AC"
    "AD"
    "AE"
    "AF"
    "AG"
    "AH"
    "AI"
    "AJ"
    "AK"
    "AL"
    "AM"
    "AN"
    "AO"
    "AP"
    "AQ"
    "BA"
    "BB"
    "BC"
    "BD"
    "BE"
    "BF"
    "BG"
    "BH"
    "BI"
    "BJ"
    "BK"
    "BL"
    "BM"

[Arif]

thanks