theredpea

import metric

(500 * metric.byte) / (4 * metric.Mbps)
#0 Need floats else it rounds
(500 * metric.byte) / (4.0 * metric.Mbps)
#0.001 Notice 4.0 (float) vs 4 (int)


size = 500 * metric.byte
rate = 4 * metric.Mbps

theredpea

#Bandwidth-Delay Product
#AKA "data in flight"
#https://d396qusza40orc.cloudfront.net/comnetworks/lect%2F2-1-physical-overview-ink.pdf

import metric

def bandwidthDelay(rate=0.00 * metric.Mbps, propDelay = (0.00 * metric.ms), unit=metric.byte):
    return ((float(rate) * propDelay) / unit)

theredpea

#Metric Units https://d396qusza40orc.cloudfront.net/comnetworks/lect%2F2-1-physical-overview-ink.pdf

Kbps = pow(10,3)
Mbps= pow(10,6)
Gbps = pow(10,9)

ms = pow(10,-3)
us = pow(10,-6)
ns = pow(10,-9)

theredpea

from util import groupBy

_4b5bmap = {'11110':'0000',
           '01001':'0001',
           '11100':'1110',
           '11101':'1111'}
#"are pre-determined in a dictionary and they are chosen to ensure that there will be at least two transitions per block of bits."
#TODO: Get the whole map from http://www.mathworks.com/matlabcentral/fileexchange/27566-4b5b-encoder-line-codificador-de-linea-4b5b/ ?

def translate4b5b(bits):

theredpea

from util import groupBy

bits='010010001111'

def translateBits(bits):

    translated = [int(_,2) for _ in groupBy(bits, 3)]

    return translated

theredpea

def groupBy(iterable, groupsize=3, strict=True):
    if strict:
        assert len(iterable)%groupsize == 0, 'Need evenly divisible'
    
    return [iterable[_:_+groupsize] for _ in range(len(iterable))[::groupsize]]   

theredpea

import math

#maximum *symbol* rate is 2B
#V signal levels; ignoring noise, max bit rate is:

def nyquistLimit(bandwidth=0.00, numSignalLevels=0.00):
    B=bandwidth
    V=numSignalLevels
    numSamplesPerSecond = 0.5#frequency
    numSecondsPerSample = 1/numSamplesPerSecond #1/frequency

theredpea

import math

def shannonCapacity(bandwidth, signal=0.0, noise=0.0, snr=0.0):
    B = bandwidth
    S = signal
    N = noise
    
    return B* math.log((1+(snr or S/N)),2)

print(shannonCapacity(20, snr=1000))

theredpea

#   -  - coding: utf-8 -  -

#  This class http://www.w3.org/International/URLUTF8Encoder.java
#  In Python
#  To understand how
#  新                  ("xin", 1st tone, means "new" in Mandarin)
#  U+65B0             (Unicode codepoint http://unicode-table.com/en/search/?q=%E6%96%B0)
#  %E6%96%B0          (URL encoding in UTF-8 http://www.url-encode-decode.com/)

#  Interesting: Not fixed-width! "新" not same size as "T"

theredpea

class BalanceTotal(SuperModel):

    #...
    
    def __getstate__(self):
        return self.js()
        
    def __setstate__(self, state):