Numerical Analysis

import numpy
from numpy import *

import matplotlib
matplotlib.use("TKAgg", False)
import pylab

import os, warnings, time, random

def F(f,x):
    x=numpy.array(x)
    return eval(f)

def isZero(x,lim=1E-16):
    return x is None or abs(x)<=lim

__scrub_nums = '0123456789'
def scrub(f):
    nf=''
    for i in range(len(f)):
        nf += f[i]
        if f[i] in __scrub_nums:
            if i+1 < len(f) and f[i+1] != '.' and f[i+1] not in __scrub_nums:
                    nf += '.0'
            elif i+1 == len(f):
                nf +='.0'

    return nf

def JDraw(pause = .001):
    """Any pause < .001 = .001"""
    pylab.draw()
    warnings.simplefilter("ignore")
    pylab.gcf().canvas.start_event_loop(timeout = pause)
    warnings.simplefilter("always")

def rebound(x,f,p=10):
    xr=max(x)-min(x)
    fr=max(f)-min(f)
    dx=xr/100.*p
    df=fr/100.*p
    xmin=min(x)-.5*dx
    xmax=max(x)+.5*dx
    fmin=min(f)-.5*df
    fmax=max(f)+.5*df
    return (xmin,xmax,fmin,fmax)

def qjplot(x,f,*args,**kwargs):
    pylab.ion()
    do_rebound = kwargs.pop('rebound',0)
    pylab.plot(x,f,*args,**kwargs)
    if do_rebound:
        (xmin,xmax,fmin,fmax)=rebound(x,f)
        pylab.xlim(xmin,xmax)
        pylab.ylim(fmin,fmax)

def qjclf():
    pylab.clf()

def qjwait():
    raw_input("Press enter to continue: ")