Using repelem to vertially concatonate non-numeric variable

I have a variable in format 1001_1_1 that changes in a loop. I want to replicate and vertcat this by different amounts each loop, to a new variable eg

1001_1_1

1001_1_1

3005_3_5

3005_3_5

3005_3_5

and so on.

Ive tried using repelem:

new_var = repelem(name, n)

new_var_all = [new_var_all; new_var];

but if e.g. n=3, this is the result: 111000000666___111___333

Please help!

Answer 1

[Star Strider]

I am not certain what you want to do, however the repmat function might be a better choice, since it allows the dimensions to be specified.

v = '1001_1_1';
new_var = repmat(v, 3, 1)

new_var = 3×8 char array
    '1001_1_1'
    '1001_1_1'
    '1001_1_1'

.

[Atsushi Ueno]

n = 3;
new_var_all = [];
name = {'1001_1_1';'3005_3_5';'6007_7_9'};
for k = 1:size(name)
new_var = repmat(name{k}, n, 1);
new_var_all = [new_var_all; new_var];
end
new_var_all

new_var_all = 9×8 char array
    '1001_1_1'
    '1001_1_1'
    '1001_1_1'
    '3005_3_5'
    '3005_3_5'
    '3005_3_5'
    '6007_7_9'
    '6007_7_9'
    '6007_7_9'

Answer 2

[Stephen23]

".. repmat function might be a better choice, since it allows the dimensions to be specified."

As does REPELEM:

repelem('1001_1_1',3,1)

ans = 3×8 char array
    '1001_1_1'
    '1001_1_1'
    '1001_1_1'

[Emu]

Ahhh thank you :)

Answer 3

[Steven Lord]

Note that the for loop approach from @Atsushi Ueno works if the "pieces" of the names are the same length all the way down the list. But if you had:

name = {'1001_1_1';'3005_3_5';'6007_7_10'}; % 10 not 9

you'd receive an error. In this case, I'd use a string array and repmat or repelem as @Star Strider and @Stephen23 suggested.

names = ["1001_1_1";"3005_3_5";"6007_7_10"];
R = repelem(names, 3, 1)

R = 9×1 string array
    "1001_1_1"
    "1001_1_1"
    "1001_1_1"
    "3005_3_5"
    "3005_3_5"
    "3005_3_5"
    "6007_7_10"
    "6007_7_10"
    "6007_7_10"

If you need the elements as char vectors (because a function you're trying to use only supports char vectors or would need to be modified to support string arrays, like if it uses concatenation to combine the name with something else) you can call char.

c = char(R(8))

c = '6007_7_10'

Another possibility, if you're trying to assemble these names from all combinations of the "pieces", is to use combinations and join.

C = combinations([1001, 3005, 6007], [1, 3, 7], [1, 5, 10]);
join(string(C.Variables), "_")

ans = 27×1 string array
    "1001_1_1"
    "1001_1_5"
    "1001_1_10"
    "1001_3_1"
    "1001_3_5"
    "1001_3_10"
    "1001_7_1"
    "1001_7_5"
    "1001_7_10"
    "3005_1_1"
    "3005_1_5"
    "3005_1_10"
    "3005_3_1"
    "3005_3_5"
    "3005_3_10"
    "3005_7_1"
    "3005_7_5"
    "3005_7_10"
    "6007_1_1"
    "6007_1_5"
    "6007_1_10"
    "6007_3_1"
    "6007_3_5"
    "6007_3_10"
    "6007_7_1"
    "6007_7_5"
    "6007_7_10"