Merging rows of a matrix into a number

If you have the 3*1 matrix

C = [345
    679
    158]

and you want to change it to the 3*3 matrix (or vice versa)

C = [3 4 5
    6 7 9
    1 5 8]

so that you can for example sort it in descending order of the columns, how would you do this? Thank you.

[Image Analyst]

@Ive J, can you put your Answer down below in the Answers section rather than up here in comments that is used to ask the original poster for clarification? You can also get credit for your answer down there if the poster accepts your answer and/or votes for it.

[Ive J]

@Image Analyst sure, tnx!

Answer 1

[Ive J]

See here https://mathworks.com/matlabcentral/answers/299422-converting-a-double-into-a-matrix-of-its-digits#answer_231586

C = [345
    679
    158];
num2str(C) - '0'
ans = 3×3
3     4     5
6     7     9
1     5     8

Answer 2

[Jan]

C = [345
     679
     158];
D = rem(floor(C ./ [100, 10, 1]), 10)

D = 3×3

3 4 5 6 7 9 1 5 8