Write a function that computes the magnitude of a vector $x.$ If $x$ has a complex component, then display the message "A complex value has been encountered" and return without computing the magnitude. Recall that the magnitude of a vector of length $n$ is given by: $\sqrt[\phantom{2}]{x_1^2+x_2^2+\text{c}\text{d}\text{o}\text{t}\text{s}+x_n^2}.$ Also, the isreal command $($learn about it using Matlab's help utility$)$ may be used.