How to plot data from multiple two column text files with legends in Matplotlib?

by

This is relatively simple if you use pylab (included with matplotlib) instead of matplotlib directly. Start off with a list of filenames and legend names, like [ (‘name of file 1’, ‘label 1’), (‘name of file 2’, ‘label 2’), …]. Then you can use something like the following:

import pylab

datalist = [ ( pylab.loadtxt(filename), label ) for filename, label in list_of_files ]

for data, label in datalist:
    pylab.plot( data[:,0], data[:,1], label=label )

pylab.legend()
pylab.title("Title of Plot")
pylab.xlabel("X Axis Label")
pylab.ylabel("Y Axis Label")

You also might want to add something like fmt=”o” to the plot command, in order to change from a line to points. By default, matplotlib with pylab plots onto the same figure without clearing it, so you can just run the plot command multiple times.

More Related Contents:

  1. Plot a function in python
  2. Histogram Matplotlib
  3. Adding a background image to a plot
  4. How to create a density plot in matplotlib?
  5. matplotlib – extracting data from contour lines
  6. Fitting a Normal distribution to 1D data
  7. how to handle an asymptote/discontinuity with Matplotlib
  8. Problem in combining bar plot and line plot (python)
  9. Matplotlib Plot Lines with Colors Through Colormap
  10. Annotate Time Series plot in Matplotlib
  11. Matplotlib runs out of memory when plotting in a loop
  12. How to plot line (polygonal chain) with numpy/scipy/matplotlib with minimal smoothing
  13. Matplotlib: how to make imshow read x,y coordinates from other numpy arrays?
  14. Pythonic way of detecting outliers in one dimensional observation data
  15. ‘invalid value encountered in double_scalars’ warning, possibly numpy
  16. How to fix ‘numpy.ndarray’ object has no attribute ‘get_figure’ when plotting subplots
  17. How to update matplotlib’s imshow() window interactively?
  18. Creating a Confidence Ellipsis in a scatterplot using matplotlib
  19. Using datetime as ticks in Matplotlib
  20. Plot the x-axis as a date
  21. Axes from plt.subplots() is a “numpy.ndarray” object and has no attribute “plot”
  22. plotting a histogram on a Log scale with Matplotlib
  23. How to center labels in histogram plot
  24. Adding colors to a 3d quiver plot in matplotlib
  25. pylab.hist(data, normed=1). Normalization seems to work incorrect
  26. How to install NumPy for python 3.3.5 on Mac OSX 10.9
  27. Save plot to numpy array
  28. How to create a density plot
  29. How to add trendline to a scatter plot
  30. Add density curve on the histogram

Leave a Comment