`from numpy import *
import matplotlib.pylab as p
from mpl_toolkits.mplot3d import Axes3D
Nx = 101; Nt = 3000; Dx = 0.03 ; Dt = 0.9
KAPPA = 210. ; SPH = 900. ; RHO = 2700. #conductivity,specfheat ,densi
+ty
T = zeros( (Nx , 2) , float ); Tpl =zeros( (Nx , 31) , float )
print ("Working, wait for figure after count to 10")
for ix in range ( 1 , Nx - 1) : T[ ix , 0] = 100.0 ; # initial temper
+ature
T [ 0 , 0 ] = 0.0 ; T [ 0 , 1 ] = 0. #first and last points a t0
T[Nx - 1 ,0] = 0. ; T[Nx - 1 ,1] = 0.0
cons = KAPPA / ( SPH*RHO) *Dt / ( Dx*Dx) ; # constant
m=1 # counter for rows , one every 300 time steps
for t in range ( 1 , Nt ) : # time iteration
for ix in range ( 1 , Nx - 1) : #Finitedifferences
T[ ix , 1] = T[ ix , 0] + cons *(T[ ix + 1 , 0] + T[ ix - 1, 0]
+ - 2.*T[ ix , 0 ] )
if t %300 == 0 or t == 1: #for t = 1 and every 300 time steps
for ix in range ( 1 , Nx - 1 , 2) : Tpl [ ix , m] = T[ ix , 1]
print (m)
m=m+1 # increasemevery 300 time steps
for ix in range ( 1 , Nx - 1): T[ ix , 0] = T[ ix , 1]# 100 p o s i
+ t o n s a t t =m
x = list ( range ( 1 , Nx - 1 , 2) ) # p l o t every o t h e r x p o i
+ n t
y = list ( range ( 1 , 30) ) # every 10 p o i n t s i n y ( time )
X, Y = p.meshgrid ( x , y ) # g r i d f o r p o s i t i o n and time
def functz ( Tpl ) : # Function r e t u r n s t e m p e r a t u r e
z = Tpl [X, Y]
return z
Z = functz ( Tpl )
fig = p.figure( ) # c r e a t e f i g u r e
ax = Axes3D ( fig ) # p l o t s a x i s
ax.plot_wireframe(X, Y, Z , color = 'r') # red wireframe
ax.set_xlabel('Position') # l a b e l axes
ax.set_ylabel('time')
ax.set_zlabel('Temperature')
p.show( ) # shows f i g u r e , c l o s e Python s h e l l
print ("finished")
`
Switching to Perl, I can change the matrix elements but I dont know how to change the dimensions of the matrix. |
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