使用 CSV 绘制平行坐标

Question

I am trying to plot a parallel coordinates graph using data froma csv file. The csv file contains four columns. An example of the data is:

A, B, C, D
1, 2, 4, 8
5, 6, 1, 5
6, 5, 5, 10

I am getting an error that No valid input arrays specified . I do not know what I am doing wrong. Here is the code I have so far.

from vtk import *
import csv

FILENAME_PARA_COORD = "htc_2.csv"

# Load the paracoordinates table from CSV file
csv_source = vtkDelimitedTextReader()
csv_source.SetFieldDelimiterCharacters(",")
csv_source.DetectNumericColumnsOn()
csv_source.SetHaveHeaders(True)
csv_source.SetFileName(FILENAME_PARA_COORD)

# Set up the parallel coordinates Representation to be used in this view
rep = vtk.vtkParallelCoordinatesRepresentation()

# Plug your reader in here for your own data
if vtk.VTK_MAJOR_VERSION <= 5:
   rep.SetInput(csv_source.GetOutput())

else:
   rep.SetInputConnection(csv_source.GetOutputPort())

# List all of the attribute arrays you want plotted in parallel coordinates
rep.SetInputArrayToProcess(0, 0, 0, 0, 'A')
rep.SetInputArrayToProcess(1, 0, 0, 0, 'B')
rep.SetInputArrayToProcess(2, 0, 0, 0, 'C')
rep.SetInputArrayToProcess(3, 0, 0, 0, 'D')

rep.SetUseCurves(0) # set to 1 to use smooth curves
rep.SetLineOpacity(0.5)

#Set up the Parallel Coordinates View and hook in the Representation
view = vtk.vtkParallelCoordinatesView()
view.SetRepresentation(rep)

# Inspect Mode determines whether your interactions manipulate the axes or
# select data
view.SetInspectMode(1) # VTK_INSPECT_SELECT_DATA =1

# Brush Mode determines the type of interaction you perform to select data
view.SetBrushModeToLasso()


# Brush Operator determines how each new selection interaction changes
# selected lines

view.SetBrushOperatorToReplace()

def ToggleInspectors(obj, event):
    # Define the callback routine which toggles between "Inspect Modes"
    if (view.GetInspectMode() == 0):
        view.SetInspectMode(1)
    else:
        view.SetInpsectMode(0)

# Hook up the callback to togle between inspect modes
# (manip axes & select data)
view.GetInteractor().AddObserver("UserEvent", ToggleInspectors)

# Set up render window
view.GetRenderWindow().SetSize(600, 300)
view.ResetCamera()
view.Render()

# Start interaction event loop
view.GetInteractor().Start()

Answer 1

One way is to create lists for each column and then convert it into an array and plot:

Eg:

A = ['1','2','3','4']     #list of strings
A = [int(i) for i in A]   #to 
O/p A = [1,2,3,4]         #list of integers

Then you can plot parallel coordinates.