Can vpasolve restrict the numerical solution to be a real number? If it can, how should I stipulate this condition?

I have eight unknown variables and eight equations. Now I use the vpasolve to find the numerical solution of the equation, hoping to get only the real solution, but the vpasolve only returns a complex solution. Can I restrict the it to output only real solutions? If I can, how should I implement it? Thank you for your reply.

Answer 1

[Dyuman Joshi]

Taken from vpasolve documentation

syms x
S = vpasolve(x^6 - x^2 == 3, x)

S = 

assume(x,'real')
S = vpasolve(x^6 - x^2 == 3, [-Inf Inf])

S = 

Answer 2

[jessie sun]

Dear @Dyuman Joshi, I used "assume" to restrict the unknown variables to be real numbers:

But the output result was not as I expected:

[Dyuman Joshi]

You have to use the range while using vpasolve > [-Inf Inf] as I did in my example code

[Walter Roberson]

https://www.mathworks.com/help/symbolic/sym.vpasolve.html#bt5205t-5

Tips:

vpasolve ignores assumptions set on variables. You can restrict the returned results to particular ranges by specifying appropriate search ranges using the argument init_param.

[jessie sun]

Thank you for your answer. By using your method, the problem has been solved.@Dyuman Joshi@Walter Roberson