Plot.py

"""
Define a Plot class to handle graph plotting.
By Sylvain MAUDUIT (Swop)
"""

import Gnuplot
from pingdom.pingdomcheck import PingdomCheck

class Plot(object):
    """Handle the generation of check results graphs
    """

    @staticmethod
    def plot(checks, rep_time_avg, reg_coef, response_time_low, response_time_high, settlement = "", file="out.ps", terminal="postscript"):
        """Plot a graph of the check results.
        
        Arguments:
        - checks: dictionary of checks results (see pingdom.PingdomCheck class)
        - rep_time_avg: The average response time
        - reg_coef: The coefficient of the linear regression model
        - response_time_low: The lower bound of response time
        - response_time_high: The higher bound of response time
        - settlement: (optional; default: blank string) The scaling decision to display on the graph
        - file: (optional; default: "out.ps") The destination path+filename of the plotted graph
        - terminal (optional; default: "postscript") The file type to use
        """
        x, y = PingdomCheck.getArrayData(checks)
        checks_count = len(x)
            
        reg_values = []
        for time in x:
            reg_values.append(reg_coef[0] * time + reg_coef[1])
            
        first_time = x[0]
        plot_times = [(time - first_time) for time in x]
        
        checks_graph = Gnuplot.Data(plot_times, y, title='Pingdom checks', with_='lines lc rgb "red" lw 2')
        average_graph = Gnuplot.Data(plot_times, [rep_time_avg]*checks_count, title='Avg. response time', with_='lines lc rgb "green" lw 1')
        resp_time_low_graph = Gnuplot.Data(plot_times, [response_time_low]*checks_count, title='Resp. time low bound', with_='lines lc rgb "grey" lw 1')
        resp_time_high_graph = Gnuplot.Data(plot_times, [response_time_high]*checks_count, title='Resp. time high bound', with_='lines lc rgb "grey" lw 1')
        lin_reg_graph = Gnuplot.Data(plot_times, reg_values, title='Resp. time tendency', with_='lines lc rgb "blue" lw 1')

        g = Gnuplot.Gnuplot()
        
        g.set_string('output', file)
        g('set terminal %s' % terminal)
        
        if(settlement != ""):
            g.set(title="Settlement: "+settlement)
            
        g.xlabel('Time (s)')
        g.ylabel('Response time (ms)')
        
        g.plot(checks_graph, average_graph, resp_time_low_graph, resp_time_high_graph, lin_reg_graph)
                
        #g.hardcopy(filename=file,terminal=terminal)