histogram.py

class Histogram:
    def __init__(self, n_bins = 0, a = 0, b = 0):
        """Crée un histograme de n_bins réparties uniformément entre a et b"""
        self._data = [0 for i in range(n_bins)]
        self._n_bins = n_bins
        self._a = a
        self._b = b

    def fill(self, x):
        """Remplis la bin correspondant à la valeur 'x'"""
        bin_number = int((x-self._a)*self._n_bins/(self._b-self._a))
        if bin_number >= 0 and bin_number < self._n_bins:
            self._data[bin_number] += 1
            return bin_number
        else:
            print("Warning, {} out of bounds.".format(x))
            return -1

    def get_maximum(self):
        """Retourne le maximum de l'histogramme"""
        maximum = self._data[0]
        for x in self._data[1:]:
            if x > maximum:
                maximum = x
        return maximum


    def draw(self):
        """Affiche l'histogramme en console"""
        y_max = self.get_maximum()
        scale = 1.
        if y_max > 50:
            scale = 50*1./y_max
            y_max = 50
        # vertical axis : 50 pxl
        y = y_max + 1
        while y > 0:
            to_print = ""
            if (y == y_max+1):
                to_print = "y ^"
            else:
                to_print = "  |"

            for x in range(self._n_bins):
                if self._data[x] >= y/scale:
                    to_print += "#"
                else:
                    to_print += " "
            print (to_print)
            y-=1

        print (" -"+"+"+(self._n_bins-1)*"-"+">")
        print ("  |"+(self._n_bins-1)*" "+"x")
        if scale != 1:
            print ("y-axis scale : 1 # = {}".format(1./scale))




if __name__=="__main__":
    h = Histogram(10,0,1)
    h.fill(0.5)
    h.fill(0.5)
    h.fill(0.5)
    h.fill(0.1)
    h.fill(2)
    h.fill(-1)
    h.draw()

    h2 = Histogram(100,-5,5)
    from random import gauss
    for i in range(int(100000)):
        h2.fill(gauss(0,1))
    h2.draw()