How to write variable to symbolic ?

A = 10; B = 15; C = 18;

 lcm_ABC = lcm(sym([A, B, C]));
 lcm_ABC = double(lcm_ABC);

 ABC_N = lcm_ABC/A + lcm_ABC/B + lcm_ABC/C;
 ABC_N = 20;
 lcm_ABC = 90;

 %i want to write it(ABC_N/lcm_ABC) as (20/90) or if may possible to write using formula (2/9)

Answer 1

[Star Strider]

Use the rats or rat functions, or format rat to display it as rational fractions in the Command Window.

[Triveni]

Tell me one thing more, how to convert stored value in variable to symbolic?

 (ABC_N/lcm_ABC) as (20/90)

[Star Strider]

Using both the rats and rat functions (with sprintf for rat):

ABC_N = 20;
lcm_ABC = 90;
rs = rats(ABC_N/lcm_ABC,6)                      % Using ‘rats’
[rtn,rtd] = rat(ABC_N/lcm_ABC);                 % Using ‘rat’
rt = sprintf('%2.0f/%2.0f', rtn*10, rtd*10)     % Display In Desired Format

rs =

    2/9  

rt =

20/90

These only affect the way the value is displayed. MATLAB retains full internal precision, so the result of this division, ‘(ABC_N/lcm_ABC)’, ‘rs’ in my code, will be stored as a double-precision floating-point value. The ‘rtn’ and ‘rtd’ values are also stored as double-precision numbers.

[Triveni]

This was not my question actually...by the way lot of thanks. I want to know that if i have a variable ABC_N = 20; and lcm_ABC = 90; can i treat 20 and 90 as symbolic? how to write 20/90 using symbolic toolbox?

[Star Strider]

My pleasure.

I did not realise you were using the Symbolic Math Toolbox.

To use the Symbolic Math Toolbox, the best (perhaps the only) way is to use the sym function for each variable:

A = 10; B = 15; C = 18;
A = sym(A);
B = sym(B);
C = sym(C);

lcm_ABC = lcm([A, B, C]);
ABC_N = lcm_ABC/A + lcm_ABC/B + lcm_ABC/C;

All the results are then symbolic as well. This will produce the result you want.