Display 1D data with Python

Description

This page details an example for plotting a graph with Python and the Matplotlib library. In this particular case, the data are read from an HDF4 file, but it can also be read from any source as long as the data are passed to Matplotlib in a numpy array.

Prerequisites

Language
  • Python
Libraries
  • pyhdf
  • matplotlib
  • numpy
Sinus_cardinal_1D

Input File

The data file used in the example below is : sinus_cardinal_1D.hdf

Output Image


The program creates the image

Source Code

from pylab    import *
from numpy    import *
from pyhdf.SD import *
 
# Path to the file
fileName = "sinus_cardinal_1D.hdf"
 
# Open HDF file for reading
filehdf = SD ( fileName )
 
# Reading attributes
print "file : ", fileName
 
# Read the SDS data
sds = filehdf.select ( 0 ).get ( )
 
# Display image
plot ( sds )
 
# Image title
title ( "Representation of the sinc function", weight = "bold", size = 22 )
 
# Axes title
ylabel ( "Amplitude", weight = "bold", size = 22 )
xlabel ( "X",         weight = "bold", size = 22 )
 
# Save the current figure to output image
savefig( "./sinus_cardinal_1D.png" )
 
# eventually display it
show()
 
# Close access to the HDF file
filehdf.end()