# A symbolic expression problem (different results in different version)

2 views (last 30 days)
Tamura Kentai on 22 Apr 2020
Edited: Walter Roberson on 25 Apr 2020
Hi, :
May I ask, I have a m-file, the content is as below, but it ran out different result in different versions of Matlab, they are 2013b & 2019a, or say, it's originally built in 2013b, but while migrating to 2019a on the other platform, it failed.
Can anyone know why, and how to solve it ? I found the issue was caused by the simple(), and the ezsym.m provided by the mathwork contributor.
The complete URL is here :
Thank you very much.
The code is here:
syms t a
fun = sin(a*t)
laplace(fun)
fun = sin(t)^2
laplace(fun)
fun = sin(t^2)
laplace(fun)
fun= 1/2 * ( exp(i*t^2) - exp(-i*t^2) )
A = laplace(fun)
% ezsym() was from Mathwork community contributor
% refer to: https://www.mathworks.com/matlabcentral/fileexchange/51195-ezsym-display-symbolic-expression-in-blank-plot
ezsym(A,26)
% simple() in Matlab2013b is ok, but failed at 2019a
simple(A)
syms s y(s)
y(s) = A
Num_Y = y(2*pi*1e4)
N_Sol = simple(Num_Y)
N_abs = double(abs(N_Sol))
N_angle = double(angle(N_Sol))

Walter Roberson on 22 Apr 2020
simple() was removed as of R2015a. Use simplify() instead.
Tamura Kentai on 24 Apr 2020
Hi, Walter:
Thank you for the sharing.
Best regards.

### Community Treasure Hunt

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

Start Hunting!

Translated by