Combining two number to one number

Dear Matlab users

Im facing the problem of combining two seperate numbers into one number. Let's say i have the number 1 and 2 and want to combine them in that order, resulting in 12. Another example could be 4 and 6, yielding 46, or 3, 6 and 7 yielding 367.. Is there any smart or simple way of doing this?

Thanks in advance, Poul

Answer 1

[Chandra Kurniawan]

a = 1;
b = 2;
c = 3;
result = strcat(num2str(a),num2str(b),num2str(c));
result = str2num(result);

Answer 2

[Image Analyst]

Use sprintf():

a = 1;
b = 2;
c = 3;
str = sprintf('%d%d%d', a, b, c) % If you want a string.
doubleStr = str2double(str) % If you want a double.

[Stephen23]

Simpler and more versatile to just have one '%d' specifier:

str = sprintf('%d', a, b, c)

Answer 3

[Poul Reitzel]

Exactly! Just went here to post my same suggestion! ;) Thanks

[Andrei Bobrov]

b = [3 6 7]

out = b*10.^(numel(b)-1:-1:0).'

[Marc Gebhardt]

Thats bad. It only works for one-digit numbers obviously.

[A C]

How does this work?

out = [30 60 70].^[2; 1; 0]

[ 900 3600 4900

30 60 70

1 1 1 ]

[Image Analyst]

Not sure what exactly you mean by "how", but the first column is

30^2 = 900

30^1 = 30

30^0 = 1

The second column is

60^2 = 3600

60^1 = 60

60^0 = 1

The third column is

70^2 = 4900

70^1 = 70

70^0 = 1

Or maybe one can just say the "how" is done by normal element-by-element operations that you should be well familiar with in MATLAB (as opposed to matrix operations which do not use the dot before the operater).

[A C]

hello, Image Analyst

I was talking about this code. It returns 367

b = [3 6 7]

out = b*10.^(numel(b)-1:-1:0)'

I thought this would look like this

out = [30 60 70].^[2; 1; 0]

but it returns a matrix.

Why are the two codes different. How does the first code return a single number?

[Image Analyst]

Well, it would be good if you had given that equation for "out" in your first post so we'd have known about it.

It's because the first vector is a row vector and the second is a column vector (because of the '). And you're using a recent version of MATLAB that does automatic expansion. Look up expansion here or in MATLAB to see what that means.