# histogram, code2.2.py
# import plotsvg   <-- not accessible
import matplotlib
import matplotlib.pyplot as plt
import numpy
import numpy as np

def linesFile(fname):
    count_line = 0
    with open(fname, 'r', encoding='utf-8') as file:
        a_line = file.readline()
        while a_line:
            count_line += 1
            a_line = file.readline()
#        count_line += 1
    return count_line

def RdFile1(fname, x):
    with open(fname, 'r', encoding='utf-8') as file:
        a_line = file.readline()
        count_line = 0
        if not a_line.isnumeric():
            print(a_line,' is not a number')
            a_line.encode('utf-8')
        x[count_line] = float(a_line)
        print("1st data: x[",count_line+1,"]= ",f"{x[count_line]:,.02f}")

        while a_line:
            a_line = file.readline()
            if len(a_line)>0:
                if not a_line.isnumeric():
#                   print(a_line,' is not a number')
                    a_line.encode('utf-8')
                count_line += 1
                x[count_line] = float(a_line)
#                print("x[",count_line+1,"]= ",f"{x[count_line]:,.02f}")
    count_line += 1 
    print("last data: x[",count_line,"]= ",f"{x[count_line-1]:,.02f}")
#    print(count_line,' lines have been read')
    if file.closed:
        print(fname + ' is closed')
    
#--- Main program starts here. ---              
print('--- Read a file and make a cumulative plot ---')
print("MatPlotLib Version." + str(matplotlib.__version__))
print("NumPy Version." + str(numpy.__version__))

fname = 'tab2.1.csv'
ndata = linesFile(fname)
xmax = 12
print(ndata, ' lines in ' + fname)
x = np.arange(ndata, dtype = 'f')
RdFile1(fname, x)

bins = np.array([6.,7.,8.,9.,10.,11.,12.])
plt.grid()
plt.hist(x, bins, histtype='bar', rwidth=0.8, color='green')

font1 = {'family':'serif','color':'blue','size':11}
plt.title("Figure 2.2  Histogram", fontdict = font1)
font2 = {'family':'serif','color':'darkred','size':12}
plt.title("Figure 2.3  Histogram", fontdict = font1)
plt.xlabel("Data value", fontdict = font2)
plt.ylabel("Number of observation", fontdict = font2)

plt.show()