I'm using wxMaxima 15.08.1 (win 10) and when I input this equation
/* [wxMaxima: input start ] */a*x+b*y+c*z=0;
I get this:
/* [wxMaxima: input end ] */cz+by+ax=0
Why does it change the term's position of the expression? It seems like in descending order somehow.
Then, if I type another equation giving all coefficients the same unknown, maxima outputs it just right.
/* [wxMaxima: input start ] */a*x^2+b*x+c=0;
/* [wxMaxima: input end ] */ax^2+bx+x=0
Maxima has its own idea of the canonical ordering of terms in "+" and "*" expressions. The canonical ordering is expressed by the function ordergreatp (equivalently orderlessp) which tells if one term comes after (respectively, before) another term. If you apply sort to a list of terms, they are sorted, by default, according to the canonical order.
By default, "+" terms are displayed in reverse order (reverse of the canonical order). When the global variable powerdisp is true, "+" terms are displayed in the canonical order. You can decide whether one order or the other works better for you.
(%i2) powerdisp;
(%o2) false
(%i3) a*x + b*y + c*z;
(%o3) c z + b y + a x
(%i4) a*x^2 + b*x + c;
2
(%o4) a x + b x + c
(%i7) powerdisp : true $
(%i8) a*x + b*y + c*z;
(%o8) a x + b y + c z
(%i9) a*x^2 + b*x + c;
2
(%o9) c + b x + a x