, line, x=None, y=None, dist=None, fmt='r-')[source]

Plot a reference line for a qqplot.

  • ax (matplotlib axes instance) – The axes on which to plot the line
  • line (str {'45','r','s','q'}) –

    Options for the reference line to which the data is compared.:

    • ‘45’ - 45-degree line
    • ’s‘ - standardized line, the expected order statistics are scaled by
      the standard deviation of the given sample and have the mean added to them
    • ’r’ - A regression line is fit
    • ’q’ - A line is fit through the quartiles.
    • None - By default no reference line is added to the plot.
  • x (array) – X data for plot. Not needed if line is ‘45’.
  • y (array) – Y data for plot. Not needed if line is ‘45’.
  • dist (scipy.stats.distribution) – A scipy.stats distribution, needed if line is ‘q’.


There is no return value. The line is plotted on the given ax.