plot of a function with multiple variables

I am trying to plot a function which gives the sum of variables x and y.

clear all
syms x y
seriessum = @(n,x,y) symsum((x./y).^i,i,i,n)       
 while i>= 1
     i = i + 1;
 end
 figure
 fplot(seriessum)
     

When using fplot, it returns the error "input must be a function or functions of a single variable" and when using fplot3 it returns the the error "not enough input arguments."

Answer 1

[Chidvi Modala]

seriessum = @(n,x,y) symsum((x./y).^i,i,i,n) is equivalent to which is not a valid expression for a function which gives the sum of variables x and y. And fplot plots a function which contains single variable but the function you specified contains 3 variables. So it was throwing "input must be a function or functions of a single variable" error. fplot3 also doesn't work in this case because fplot3(funx,funy,funz) plots a parametric curve where funx, funy, funz are the functions of a single variable.

You can make use of fcontour or fmesh based on you requirement.