Make seeds for Juno Bfield lines

It reads Mathematica created lat-lon grids of different densities and uses it to generate a single non-uniform grid file that can be used to seed field lines in Paraview for generating 3D field line plot.

Author: rakesh-yadav

Make_seed_points_for_Juno_field.py

@@ -0,0 +1,92 @@
+import random
+import numpy as np
+import matplotlib.pyplot as plt
+from scipy.interpolate import griddata
+
+#print test_data.shape
+#juno_data = np.loadtxt('Juno_field.txt').T
+#field_mag = np.absolute(juno_data)
+
+# grid for juno field
+juno_data = np.loadtxt('Juno_field.txt').T
+field_mag = np.absolute(juno_data)
+pphi, ttheta = np.mgrid[0:2.*np.pi:1024*1j, 0:np.pi:512*1j]
+pphi = pphi.flatten(); ttheta = ttheta.flatten()
+
+
+def chose_grid(grid,minB,maxB):
+ if grid==250:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/0.25k.dat')
+ elif grid==500:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/0.5k.dat')
+ elif grid==750:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/0.75k.dat')
+ elif grid==1000:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/1k.dat')
+ elif grid==1250:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/1.25k.dat')
+ elif grid==1500:
+  data = np.loadtxt('mathematica_1.5k_to_0.25k/1.5k.dat')
+ x = data[:,0]
+ y = data[:,1]
+ z = data[:,2]
+ 
+ #convert to lat, lon
+ r = np.sqrt(x**2 + y**2 + z**2)
+ ttheta1 = np.arccos(z/r)
+ pphi1 = np.arctan2(y,x)+np.pi
+ #pphi1, ttheta1 = np.meshgrid(phi1,theta1)
+ #print phi1.min(), phi1.max(), theta1.min(), theta1.max()
+
+ interp_data = griddata((pphi, ttheta), field_mag.flatten(), (pphi1, ttheta1), method='nearest')
+ print interp_data.shape
+ #plt.hist(interp_data)
+ #plt.show()
+
+ #new x,y,z with smaller radius
+ x = 1.6*np.sin(ttheta1)*np.cos(pphi1)
+ y = 1.6*np.sin(ttheta1)*np.sin(pphi1)
+ z = 1.6*np.cos(ttheta1)
+
+ trunc_x = x[np.where( ((minB < interp_data) & (interp_data < maxB)) )]
+ trunc_y = y[np.where( ((minB < interp_data) & (interp_data < maxB)) )]
+ trunc_z = z[np.where( ((minB < interp_data) & (interp_data < maxB)) )]
+
+ return trunc_x,trunc_y,trunc_z
+
+#------------------------
+f=open("seeds.csv","w+")
+f.write('x coord, y coord, z coord\n')
+
+x1,y1,z1 = chose_grid(1500,50,65)
+
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+
+x1,y1,z1 = chose_grid(1250,40,50)
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+
+x1,y1,z1 = chose_grid(1000,30,40)
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+
+x1,y1,z1 = chose_grid(750,20,30)
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+ 
+x1,y1,z1 = chose_grid(500,10,20)
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+
+x1,y1,z1 = chose_grid(250,0,10)
+for i in range(len(x1)):
+ to_write = "%f, %f, %f" %(x1[i], y1[i], z1[i])
+ f.write(to_write+'\n')
+
+f.close()