# How to plot a curvilinear domain using Plots?

Hello Everyone,

I have been trying to create the same plot here that I created using PyPlot, but now using Plots. Does anyone know how to work around this issue?

``````using PyPlot
# ion()
# pygui(true)

r_ini = 1.0
r_end = 2.0 # range in r-direction
θ_ini = 0.0
θ_end = π/2 # range in θ-direction
n = 31

# Spatial grid for the numerical solution
r = range(r_ini, stop=r_end, length=n)
θ = range(θ_ini, stop=θ_end, length=n)'

x1 = r .* cos.(θ)
y1 = r .* sin.(θ)
z = ones(size(x1))

contourf(x1, y1, z', title="Initial Condition", color=:viridis)
#contourf(r, θ', z, title="Initial Condition", color=:viridis)

display(gcf())
``````

Now with Plots:

``````using Plots

r_ini = 1.0
r_end = 2.0 # range in r-direction
θ_ini = 0.0
θ_end = π/2 # range in θ-direction
n = 100

# Spatial grid for the numerical solution
r = range(r_ini, stop=r_end, length=n)
θ = range(θ_ini, stop=θ_end, length=n)

x1 = r .* cos.(θ)
y1 = r .* sin.(θ)
z = ones(n, n) # Ensure z has the correct dimensions

contourf(x1, y1, z, title="Initial Condition", color=:viridis)
``````

Also it shows in the REPL that either “Arrays have incorrect length or dimension.” or “points not sorted in ascending order”.

Can someone help me with this? Thanks in advance!

It works using Plots’ `pyplot()` backend.

1 Like

Thanks @rafael.guerra !