I'm trying to plot a line segment between the points [1,1] and [0,0] in the surface Z function x^2 + y^2, i've already plotted f with:

```
using PyPlot
using Distributions
function f(x)
return (x[1]^2 + x[2]^2)
#return sin(x[1]) + cos(x[2])
end
n = 100
x = linspace(-1, 1, n)
y = linspace(-1,1,n)
xgrid = repmat(x',n,1)
ygrid = repmat(y,1,n)
z = zeros(n,n)
for i in 1:n
for j in 1:n
z[i:i,j:j] = f([x[i],y[j]])
end
end
plot_wireframe(xgrid,ygrid,z)
```

I know already about R (ggplot2) and C, but i'm new with python and julia librarys like matlibplot