More versatility of function plot_distr_funct in script

distribution_function.py. Plot two distribution functions and two
histograms for positive speed and absolute value of negative speed.

Analysis/distribution_function.py

@@ -4,27 +4,26 @@ import shapefile
 import numpy as np
 import matplotlib.pyplot as plt
 
-def plot_distr_funct(X, xlabel):
-    plt.figure()
-    plt.hist(X, bins="auto")
-    plt.xlabel(xlabel)
-    plt.ylabel("number of occurrences")
+def plot_distr_funct(X, xlabel, label = None, ax = None):
+    """Sort and plot distribution function."""
     
-    X = np.array(X)
     X.sort()
     nx = np.size(X)
-
-    print(xlabel + ":")
+    if ax is None: ax = plt.gca()
+    ax.plot(X, (1 + np.arange(nx)) / nx, label = label)
     print("minimum value:", X[0])
     print("maximum value:", X[-1])
     print("number of values:", nx, "\n")
 
-    plt.figure()
-    plt.plot(X, (1 + np.arange(nx)) / nx)
-    plt.xlabel(xlabel)
-    plt.ylabel("distribution function")
+def read(end_filename):
+    """Return speed, radius of outermost contour and radius of maximum speed
+    contour from three dbf files, as Numpy arrays.
+
+    Select valid speed values and valid outermost contour (with
+    sufficient area).
 
-def get_var(end_filename):
+    """
+    
     with shapefile.Reader("extremum" + end_filename) as extremum, \
          shapefile.Reader("outermost_contour" + end_filename) as outermost_cont:
         speed = []
@@ -42,7 +41,7 @@ def get_var(end_filename):
         for rec in max_speed_contour.iterRecords():
             if rec.r_eq_area != - 100: r_speed.append(rec.r_eq_area)
 
-    return speed, r_outer, r_speed
+    return np.array(speed), np.array(r_outer), np.array(r_speed)
 
 if __name__ == "__main__":
     import argparse
@@ -54,13 +53,55 @@ if __name__ == "__main__":
                         default = "")
     args = parser.parse_args()
 
-    speed, r_outer, r_speed = get_var(args.end_filename)
+    speed, r_outer, r_speed = read(args.end_filename)
+
+    X = speed[speed >= 0]
+    xlabel = "speed, when positive, in m s-1"
+    
+    plt.figure()
+    plt.hist(X, bins = "auto")
+    plt.xlabel(xlabel)
+    plt.ylabel("number of occurrences")
+
+    plt.figure()
+    print(xlabel + ":")
+    plot_distr_funct(X, "speed, in m s-1")
+    ax_distr_speed = plt.gca()
+
+    X = - speed[speed < 0]
+    xlabel = "- speed, when negative, in m s-1"
+    plt.figure()
+    plt.hist(X, bins = "auto")
+    plt.xlabel(xlabel)
+    plt.ylabel("number of occurrences")
+
+    print(xlabel + ":")
+    plot_distr_funct(X, xlabel, ax = ax_distr_speed)
+    
+    xlabel = "equivalent radius of outermost contour, in km"
 
-    plot_distr_funct(speed, "speed, in m s-1")
-    plt.axhline(0.5, linestyle = "--", color = "black")
-    plt.axvline(linestyle = "--", color = "black")
+    plt.figure()
+    plt.hist(r_outer, bins = "auto")
+    plt.xlabel(xlabel)
+    plt.ylabel("number of occurrences")
 
-    plot_distr_funct(r_outer, "equivalent radius of outermost contour, in km")
-    plot_distr_funct(r_speed, "equivalent radius of max-speed contour, in km")
+    plt.figure()
+    print(xlabel + ":")
+    plot_distr_funct(r_outer, xlabel)
+    plt.xlabel(xlabel)
+    plt.ylabel("distribution function")
+    
+    xlabel = "equivalent radius of max-speed contour, in km"
+
+    plt.figure()
+    plt.hist(r_speed, bins = "auto")
+    plt.xlabel(xlabel)
+    plt.ylabel("number of occurrences")
 
+    plt.figure()
+    print(xlabel + ":")
+    plot_distr_funct(r_speed, xlabel)
+    plt.xlabel(xlabel)
+    plt.ylabel("distribution function")
+    
     plt.show()

GNUmakefile

 # This is a makefile for GNU make.
 
+makefile_dir = .
 include ${general_compiler_options_dir}/settings.mk
 
 # 1. Source files and libraries
 
-makefile_dir = .
 VPATH += ${makefile_dir}/Tests
 
 src_test_local_extrema = test_local_extrema.f local_extrema.f