Calculate average coordinate of several peaks (sparky script)

From NMR Wiki

1 Overview
2 Installation
3 Bugs
4 Code

Overview

Select several peaks and calculate average coordinate in Hertz

Installation

with plain text editor create file calc_ave_freq.py in python/sparky directory which is located in the root of sparky installation
paste code below into that file, save and close file
open file sparky_site.py
find peak_menu array in the file and add line highligthed in red into that array as shown below

peak_menu = (
    ('hc', 'HC peaks',                  ('hcpeaks','show_dialog')),
    ('af', 'Calculate average frequenies',        ('calc_ave_freq','show_dialog')),

when you open some file in sparky, select some peaks and type 'af' average frequencies should be shown in a pop-up window

Bugs

Info window won't go away when "ok" button is clicked.

Code

Please feel free to improve the code.

import Tkinter
import noesy
import pyutil
import sputil
import tkutil
 
def show_dialog(session):
    tk = session.tk
    window = Tkinter.Toplevel(tk) 
 
    view = session.selected_view()
    spectrum = view.spectrum
    peaks = spectrum.selected_peaks()
    num_peaks = len(peaks)
 
    if num_peaks <= 1 :
        message = 'Select two or more peaks!'
    else:
        dim = len(peaks[0].position)
 
        ave = [0,0,0]
        for i in range(dim):
            ave[i] = 0
 
        for p in peaks:
            for i in range(dim):
                ave[i] = ave[i] + p.position[i]
 
        npeaks = len(peaks)
 
        for i in range(dim):
            ave[i] = ave[i]/npeaks
 
 
        message = ''
 
        lbl = ('F1:','F2:','F3:')
        for i in range(dim):
        #x y z must correspond to actual xyz (axis order!)
        #print hertz instead of ppms
            ppm = spectrum.hz_per_ppm[i]
            ave[i] = ave[i]*ppm
            output = '%.2f' % ave[i]
            message = message + lbl[i] + str(output) + '\n'
    lbl = Tkinter.Label(window,text=message)
    lbl.pack()
 
    btn = Tkinter.Button(window,text='ok')
    btn.pack()