import numpy as np

# nb of grid points in x and y directions
N = 10

# Positions over -1 to 1 interval
x = np.linspace(-1.0, 1.0, N, endpoint= True)
y = np.linspace(-1.0, 1.0, N, endpoint= True)

X, Y = np.meshgrid(x, y)
Z = np.zeros((N, N))

# Velocities and forces are set to 0 (material points)
V_x = np.zeros((N, N))
V_y = np.zeros((N, N))
V_z = np.zeros((N, N))

F_x = np.zeros((N, N))
F_y = np.zeros((N, N))
F_z = np.zeros((N, N))

# Temperature and heat source
T = np.ones((N,N)) # uniform T
H_v = np.zeros((N,N)) # no heat source


# Rearrange the data to be written into the input csv file
X = X.flatten(order='C')
Y = Y.flatten(order='C')
Z = Z.flatten(order='C')
V_x = V_x.flatten(order='C')
V_y = V_y.flatten(order='C')
V_z = V_z.flatten(order='C')
F_x = F_x.flatten(order='C')
F_y = F_y.flatten(order='C')
F_z = F_z.flatten(order='C')
T = T.flatten(order='C')
H_v = H_v.flatten(order='C')

output = np.column_stack((X, Y, Z, V_x, V_y, V_z, F_x, F_y, F_z, T, H_v))

np.savetxt('input.csv', output, delimiter=' ')