Change the range of the axes' plots

[Andersongeofisco]

Hello everyone! I hope that everyone is fine. I have a doubt :) I'd like to know if it is possible to change the range of the axes in a volume plot for example. The axes of my plots always start from 0 to length of my 3d numpy array, I'd like to plot for example something like, -5 to 5 (-5,-4,-3,-2,-1,0,1,2,3,4,5) instead (0,1,2,3,4,5,6,7,8,9,10) at the axes.

Thanks!

[banesullivan]

Hi, @Andersongeofisco! Do you have any code to go with your question so that I can help you implement this with your workflow?

It sounds like you are using PyVista strictly for plotting and passing a 3D numpy array to the Plotter's add_mesh or add_volume methods to render that dataset. Behind the scenes when you do this, an UniformGrid object is created of your 3D data. I'd recommend creating a PyVista dataset before plotting and properly set the spatial reference of that dataset. For example:

import numpy as np
import pyvista as pv

# Create a 3D numpy array like what is used
arr = np.arange(1000).reshape((10,10,10))

# Create a PyVista UniformGrid for the 3D array
grid = pv.UniformGrid()
# Set the spatial reference
grid.dimensions = np.array(arr.shape) + 1 #dim + 1 because cells
grid.origin = (-5, -5, -5)
grid.spacing = (1, 1, 1)
# Add data arrays
grid['data'] = arr.ravel(order='F')

# Now plot the properly referenced dataset
grid.plot(show_grid=True, show_edges=True)

[Andersongeofisco]

Hi @banesullivan ! Here is a example of my code.

import pyvista as pv
import numpy as np
ns=401
nv=21
nps=52
dado1=open("dvp3.ad",'rb')
d=np.fromfile(dado1,dtype=np.float32,count=ns*nv*nps).reshape([ns,nv,nps],order='F')

a=pv.wrap(d)
outline = a.outline()
slices = a.slice_orthogonal(x=401,y=5,z=52)
p = pv.Plotter()
p.add_mesh(outline)
p.add_mesh(slices,cmap='jet',opacity=1.,stitle="Semblance")
p.add_volume(a,cmap='jet',stitle="Semblance")
p.add_text("Semblance",position='upper_edge')
p.show_bounds(xlabel='Time',ylabel='Velocity',zlabel='Slope',location='outer')
p.show()

[banesullivan]

So the a object is a pv.UniformGrid in your example. You create in manually without wrap like:

a = pv.UniformGrid()
# Set the spatial reference
a.dimensions = np.array(arr.shape) + 1 #dim + 1 because cells
a.origin = (-5, -5, -5)
a.spacing = (1, 1, 1)
# Add data arrays
a['Semblance'] = d.ravel(order='F')

[Andersongeofisco]

Thanks @banesullivan for your help! You helped a lot this young phd student :)

[Andersongeofisco]

I will try it and if everything works well I will return to say thanks.

[Andersongeofisco]

Hi @banesullivan ! I tried your tip, but I get another problem now. If I try to use the a object that was created to add_volume or slice I have this error message:

ERROR:root:Cell Scalars not supported
Falha de segmentação (imagem do núcleo gravada)

Here is my code:

import pyvista as pv
from pyvista import examples
import numpy as np
import matplotlib.pyplot as plt

ns=401
nv=21
nps=52
dado1=open("dvp3.ad",'rb')
d=np.fromfile(dado1,dtype=np.float32,count=nsnvnps).reshape([ns,nv,nps],order='F')

a = pv.UniformGrid()

a.dimensions = np.array(d.shape) + 1 #dim + 1 because cells
a.origin = (-5, -5, -5)
a.spacing = (1, 1, 1)
#Add data arrays
a['Semblance'] = d.ravel(order='F')

outline = a.outline()
slices = a.slice_orthogonal(x=401,y=5,z=52,contour='True')
p = pv.Plotter()
p.add_mesh(outline)
p.add_mesh(slices,cmap='jet',opacity=1.,stitle="Semblance")
p.add_volume(a,cmap='jet',stitle="Semblance")
p.add_text("Semblance",position='upper_edge')
p.show_bounds(xlabel='Time',ylabel='Velocity',zlabel='Slope',location='outer')
p.show()

[banesullivan]

Ah, my bad. Take away that + 1 when setting the dimensions. I order for it to stretch from -5 to 5, you may need to adjust the spacing to something other than 1

_{Sent with GitHawk}

[Andersongeofisco]

Thanks again @banesullivan! Everything is working well now. Thank you very much!