Grid To Grid manipulation¶
import numpy as np
import pandas as pd
import sys
import os
import gstlearn as gl
import gstlearn.plot as gp
import matplotlib.pyplot as plt
Setting some global variables
# Set the Global Options
verbose = True
flagGraphic = True
# Define the Space Dimension
ndim = 2
gl.defineDefaultSpace(gl.ESpaceType.RN, ndim)
# Set the Seed for the Random Number generator
gl.law_set_random_seed(5584)
We first define a 2-D grid with 150 x 100 nodes (unit mes size)
nx = 150
ny = 100
grid = gl.DbGrid.create([nx,ny])
On this grid we simulation (using Turning Bands method) two variables which will serve as the Top and Bottom for the next steps. For generality, we have truncated the two surfaces arbitrarily. Note taht we did not check that the Top surface is located above the Bottom surface, nor that the masked areas coincide.
model = gl.Model.createFromParam(type=gl.ECov.CUBIC, range=30, sill=10.)
err = gl.simtub(None, grid, model, None, 2)
grid.setName("Simu.1","Top")
grid.setName("Simu.2","Bot")
grid["Bot"] = grid["Bot"] + 100
grid["Top"] = grid["Top"] + 110
replace_mask = grid["Bot"] > 105
grid[np.where(replace_mask),"Bot"] = np.nan
replace_mask = grid["Top"] < 105
grid[np.where(replace_mask),"Top"] = np.nan
print("Range for Bottom = ",round(np.nanmin(grid["Bot"]),3),round(np.nanmax(grid["Bot"]),3))
print("Range for Top = ", round(np.nanmin(grid["Top"]),3),round(np.nanmax(grid["Top"]),3))
Range for Bottom = 90.831 105.0 Range for Top = 105.001 119.101
ax = grid.plot("Bot")
ax = grid.plot("Top")
We now generate the maps of the Variable to be interpolated, with one version corresponding to the Top position and another version for the Bottom position. In order to enhance the interpolation feature, the two versions of this variable are simulated with different textures: short range at the Top and much longer range at the Top
model = gl.Model.createFromParam(type=gl.ECov.CUBIC, range=30, sill=10.)
err = gl.simtub(None, grid, model)
grid.setName("Simu","VBot")
model = gl.Model.createFromParam(type=gl.ECov.SPHERICAL, range=10, sill=3.)
err = gl.simtub(None, grid, model)
grid.setName("Simu","VTop")
ax = grid.plot("VBot")
ax.decoration(title="Variable at Bottom Position")
ax = grid.plot("VTop")
ax.decoration(title="Variable at Top Position")
print("Range for Bottom = ",round(np.nanmin(grid["Bot"]),3),round(np.nanmax(grid["Bot"]),3))
print("Range for Top = ", round(np.nanmin(grid["Top"]),3),round(np.nanmax(grid["Top"]),3))
Range for Bottom = 90.831 105.0 Range for Top = 105.001 119.101
We create a 3D grid which covers the variation of the variables Top and Bot (as simulated above), i.e. from 91 to 119.
nx = 150
ny = 100
nz = 30
g3D = gl.DbGrid.create([nx,ny,nz],x0=[0,0,91])
grid.setLocators(["VBot", "VTop"],gl.ELoc.Z)
err = gl.dbg2gInterpolate(grid, g3D, ["Top"], ["Bot"])
We obtain the following statistics on the newly created variable
dbfmt = gl.DbStringFormat()
dbfmt.setFlags(flag_stats=True)
dbfmt.setNames(["Interpolation"])
g3D.display(dbfmt)
Data Base Grid Characteristics ============================== Data Base Summary ----------------- File is organized as a regular grid Space dimension = 3 Number of Columns = 5 Total number of samples = 450000 Grid characteristics: --------------------- Origin : 0.000 0.000 91.000 Mesh : 1.000 1.000 1.000 Number : 150 100 30 Data Base Statistics -------------------- 5 - Name Interpolation - Locator z1 Nb of data = 450000 Nb of active values = 156484 Minimum value = -6.055 Maximum value = 9.049 Mean value = 0.861 Standard Deviation = 2.189 Variance = 4.790 Variables --------- Column = 0 - Name = rank - Locator = NA Column = 1 - Name = x1 - Locator = x1 Column = 2 - Name = x2 - Locator = x2 Column = 3 - Name = x3 - Locator = x3 Column = 4 - Name = Interpolation - Locator = z1
Let us now visualize some horizontal slices of the 3-D grid.
fig, axs = plt.subplots(2,2,figsize=(20,10))
axs[0,0].gstgrid(g3D,corner=[0,0,10], flagLegendRaster = False)
axs[0,0].decoration(title="Slice 10")
axs[0,1].gstgrid(g3D,corner=[0,0,13], flagLegendRaster = False)
axs[0,1].decoration(title="Slice 13")
axs[1,0].gstgrid(g3D,corner=[0,0,16], flagLegendRaster = False)
axs[1,0].decoration(title="Slice 16")
axs[1,1].gstgrid(g3D,corner=[0,0,20], flagLegendRaster = False)
axs[1,1].decoration(title="Slice 20")
fig.subplots_adjust(right=0.7)
cbar_ax = fig.add_axes([0.75, 0.1, 0.02, 0.75])
im = axs[0,0].collections[0] # get mappable described by the colorbar
err = fig.colorbar(im, cax = cbar_ax)
