NameError mlab not defined

[PythonAndArduino]

I wrote a program to analyze ECG rhythms. It works on my computer, but I emailed it to a friend for them to run it and suddenly it's saying that mlab is not defined. The whole program hangs up and it won't proceed. Why does it work for me and not for him?

"""
Created on Fri Nov  3 11:57:12 2017

@author: CB
"""



import numpy as np
import peakutils
from peakutils.plot import plot as pplot
from matplotlib import pyplot
from matplotlib.mlab import detrend
import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
root.withdraw()

file = filedialog.askopenfilename()
print(file)


file = open(file).read().split('\n')
row1 = file[0].split(' ')
y = np.array(file[1:len(file)-1]).astype(np.float)
timeStep = float(row1[5])
x = [i for i in range(len(file)-2)]
x = np.array(x)

def savitzky_golay(y, window_size, order, deriv=0, rate=1):
    from math import factorial

    try:
        window_size = np.abs(np.int(window_size))
        order = np.abs(np.int(order))
    except ValueError:
        raise ValueError("window_size and order have to be of type int")
    if window_size % 2 != 1 or window_size < 1:
        raise TypeError("window_size size must be a positive odd number")
    if window_size < order + 2:
        raise TypeError("window_size is too small for the polynomials order")
    order_range = range(order+1)
    half_window = (window_size -1) // 2
    # precompute coefficients
    b = np.mat([[k**i for i in order_range] for k in range(-half_window, half_window+1)])
    m = np.linalg.pinv(b).A[deriv] * rate**deriv * factorial(deriv)
    # pad the signal at the extremes with
    # values taken from the signal itself
    firstvals = y[0] - np.abs( y[1:half_window+1][::-1] - y[0] )
    lastvals = y[-1] + np.abs(y[-half_window-1:-1][::-1] - y[-1])
    y = np.concatenate((firstvals, y, lastvals))
    return np.convolve( m[::-1], y, mode='valid')

y = savitzky_golay(y,49,5)
y = savitzky_golay(y,39,5)
y = savitzky_golay(y,59,5)

y = mlab.detrend(y)

rPeaks = peakutils.indexes(y, thres=0.9, min_dist=100)
peaks = peakutils.indexes(y, thres=0.3, min_dist=20)
nidx = peakutils.indexes(-y,thres = .85, min_dist = 25)
pyplot.figure(figsize=(10,6))
pplot(x,y, nidx)
pplot(x,y, rPeaks)
pyplot.title('ECG Data')



r_r = []        
for i in range (0,len(rPeaks)-1):
    r_r.append((rPeaks[i+1]-rPeaks[i])*timeStep)
r_r = np.array(r_r)
dev = np.std(r_r*1000)   

peakRat = len(peaks)/len(rPeaks)

heartRate = 60/np.mean(r_r)
print('Heart Rate:')
print(heartRate)

if dev > 200:
    print('Diagnosis: \nAV Block Second Degree')
elif heartRate >100:
    print('Diagnosis:\nSinus Tachycardia')
elif heartRate < 60 and dev < 5:
    print('Diagnosis: \nSinus Bradycardia')
elif dev > 5 and dev < 80:
    print('Diagnosis:')
    if peakRat > 5:
        print('Atrial Fibrillation')
    elif peakRat < 5:
        print('Sinus Arrythmia')
elif dev < 5:

    pri = []
    qrs = []
    for i in range(1,len(rPeaks)-1):
        bBnd = rPeaks[i]-500
        xrange = np.where((peaks>bBnd)*(peaks<rPeaks[i]))
        xrange = np.array(xrange[0])
        qrs.append(((nidx[2*i+1])-(nidx[2*i]))*timeStep*1.7)
        pri.append((rPeaks[i]-peaks[xrange])*timeStep*100)
    qrs = np.mean(np.array(qrs))    
    pri = np.mean(np.array(pri))
    
    if pri >20:
        print('Diagnosis:\nAV Block First Degree')
    elif qrs > .1:
        print('Diagnosis:\nBundle Branch Block')
    elif qrs < .1:
        print('Diagnosis:\nNormal')

Granted, you won't have the files to put through it's analysis, but he is getting this error:

Error:
y = mlab.detrend(y)

NameError: name 'mlab' is not defined