utils.py

"""
Utility functions

Author(s): Wei Chen (wchen459@gmail.com)
"""

import os
import itertools
import time

import numpy as np


def convert_sec(sec):
    if sec < 60:
        return "%.2f sec" % sec
    elif sec < (60 * 60):
        return "%.2f min" % (sec / 60)
    else:
        return "%.2f hr" % (sec / (60 * 60))

class ElapsedTimer(object):
    def __init__(self):
        self.start_time = time.time()
    def elapsed_time(self):
        return convert_sec(time.time() - self.start_time)
    
def gen_grid(d, points_per_axis, lb=0., rb=1.):
    ''' Generate a grid in a d-dimensional space 
        within the range [lb, rb] for each axis '''
    
    lincoords = []
    for i in range(0, d):
        lincoords.append(np.linspace(lb, rb, points_per_axis))
    coords = list(itertools.product(*lincoords))
    
    return np.array(coords)

def mean_err(metric_list):
    n = len(metric_list)
    mean = np.mean(metric_list)
    std = np.std(metric_list)
    err = 1.96*std/n**.5
    return mean, err
    
def safe_remove(filename):
    if os.path.exists(filename):
        os.remove(filename)

def create_dir(path):
    if not os.path.isdir(path):
        os.mkdir(path)