# keep from evaluating a symbolic expression

2 views (last 30 days)
Chad on 3 Jul 2022
Answered: Walter Roberson on 5 Jul 2022
Utter noob question but Im trying to build up a function and see it in with nice formatting in live script how do I keep it from evaluating?
Say below I want to make sure that I have typed it in correctly not auto evaluate it . Also is there anyway to use e as asymbol and not have it automatically evaluate it into its fractional form? Sorry for how basic this is Im sadly only on hour number 3 of this langauge .
4*pi^2 * (2*pi*100)^2 *1/5
##### 2 CommentsShowHide 1 older comment
Walter Roberson on 4 Jul 2022
Pi = sym(pi);
E = exp(sym(1));
4*Pi^2 * (2*E*100)^2 * 1/5
ans =

Abhijeet on 4 Jul 2022
I understand you want to visualize the expression without it getting evaluated.
This can be achieved using symbolic variables, but still, constants will be evaluated to a simplified expression.
Create ‘pi’ as a symbolic variable as demonstrated below:
Use 'e' as a symbolic variable to represent ‘e’ as an exponent constant without it getting evaluated.
Here is a demonstration to create symbolic variables:
For more insights on symbolic variables, kindly visit the below mentioned hyperlinks:
##### 2 CommentsShowHide 1 older comment
Chad on 5 Jul 2022
Awesome , thanks for yalls help

Walter Roberson on 5 Jul 2022
You can use displayFormula on the character (or string()) version of the formula, and later convert that to symbolic
as_char = '4*pi^2 * (2*pi*100)^2 *1/5'
as_char = '4*pi^2 * (2*pi*100)^2 *1/5'
displayFormula(as_char)
as_sym = str2sym(as_char)
as_sym =

R2022a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by