why is the "pretty" command does not work in the script,but works when I press it in the command windo?

hello I have this command

syms A D k x_0 

eqn_1=A*(exp(k*x_0)-exp(-k*x_0))==D*exp(-k*x_0)
eqn_2=-k*D*exp(-k*x_0)-k*A*(exp(k*x_0)+exp(-k*x_0))==1

sol = solve([eqn_1, eqn_2], [A D ])
A=(sol.A)
D=(sol.D)
A=pretty(A)
D=pretty(D)

my question is why when the pretty comand apprers in the script it does not work but when i press the command in the command window it works ?

Answer 1

[Stephan]

Hi,

try this:

syms A D k x_0 

eqn_1=A*(exp(k*x_0)-exp(-k*x_0))==D*exp(-k*x_0)
eqn_2=-k*D*exp(-k*x_0)-k*A*(exp(k*x_0)+exp(-k*x_0))==1

sol = solve([eqn_1, eqn_2], [A D ])
A=(sol.A)
D=(sol.D)
pretty(A)
pretty(D)

This gives you:

A =

-exp(-k*x_0)/(2*k)

D =

-(exp(k*x_0) - exp(-k*x_0))/(2*k)

    exp(-k x_0)
  - -----------
        2 k

    exp(k x_0) - exp(-k x_0)
  - ------------------------
               2 k

The way you did it makes an error in both cases (command window and script):

Error using sym/pretty
Too many output arguments.

So use:

pretty(A)
pretty(D)

instead of

A = pretty(A)
D = pretty(D)

Best regards

Stephan