How can I make a surface plot in python for data that is in external files (having three columns)? I referred to so many links online but it is really confusing.
You would have to combine the three data sets into a single data set.
Look at Matplotlib for very powerful plotting capability in Python --- they do meshes and surfaces.
In order to do full 3-D spherical plots, look at Mayavi.
good luck
Dear Sudharsan,
I guess your data set is not in a uniform grid.
I wrote you an example plotting a heat map with contour lines.
For more information look at the matplotlib website (http://matplotlib.org/index.html) preferable screen the examples in the 'gallery' and have a look at the code referring to the plot design of interest.
Best,
Frank
If the difficulty is to read the file with three columns, this can be resolved thus:
x = []
y = []
z = []
myfile = open('filename.txt', 'rb')
for line in myfile:
....row = line.split()
....x.append(float(row[0]))
....y.append(float(row[1]))
....z.append(float(row[2]))
or I also recommend looking about the library pandas (http://pandas.pydata.org/). In this case is depending on the file format, you can do this:
import pandas as pd
df = pd.read_csv('yourfile.csv')
watch this video: https://www.youtube.com/watch?v=MxRMXhjXZos
you can also find various ways to represent your data in matplotlib gallery. as:
http://matplotlib.org/examples/mplot3d/trisurf3d_demo.html
http://matplotlib.org/examples/mplot3d/subplot3d_demo.html
http://matplotlib.org/examples/mplot3d/contour3d_demo3.html
Definitely go for mayavi , either by using mlab or by importing your txt file in python assigning the array to a variable and then use mayavi.mlab.surf(x,y,z)
I am also learning these things... but this is what I know so far, from the top of my heard, about reading a say *.dat file from my C drive...
>>> import numpy
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>>
>>> data = numpy.loadtxt('C:\Python33\MyScripts\data.DAT')
>>> print (data) #prints out the newly created data array
>>>
>>> x,y,z = np.loadtxt('C:\Python33\MyScripts\data.DAT',unpack=True)
>>> x,y,z = zip(*data)
>>>
>>> plt.plot(x, y, z)
>>>
>>> ....a whole lot of junk can come here to make the plot look good
let us know if it works... or whatever works.
Ron
>>> import numpy as N
>>> import pylab as pl
>>> from matplotlib import axes3d
>>> from myFunctions import z_func
>>>
>>> x,y,z = np.loadtxt( 'data.dat' , unpack=True)
>>> x,y,z = zip(*data)
>>>
>>> X,Y = pl.meshgrid(x, y)
>>> Z = z_func(X, Y)
>>>
>>> fig = pl.figure()
>>> ax = axes3d.Axes3D(fig)
>>> ax.plot_surface(X,Y,Z)
>>> ax.set_xlabel(’X [Units] ---> ’)
>>> ax.set_ylabel(’Y [Units] ---> ’)
>>> ax.set_zlabel(’Z [Units] ---> ’)
>>>
>>>pl.show()
You can refer to this link.:
http://docs.enthought.com/mayavi/mayavi/mlab.html
I hope it will help you to get rid of this problem.
Sudharsan Balasubramanian, I'll help you!!!! I do this with some lines in python using PANDAS, the plot is beatiful!
You just have to open your terminal and write:
python 3d_plot.py "FILENAME_CONTAING_3_COLUMMS"
Be happy my friend!
THECODE:
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
import numpy as np
import pandas as pd
from sys import argv
file = argv[1]
x,y,z = np.loadtxt(file, unpack=True)
df = pd.DataFrame({'x': x, 'y': y, 'z': z})
fig = plt.figure()
ax = Axes3D(fig)
surf = ax.plot_trisurf(df.x, df.y, df.z, cmap=cm.jet, linewidth=0.1)
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.savefig('teste.pdf')
plt.show()
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