I am new to python, pythonista and programming an ui for ipad. Pythonista has been great for all of this... great app.

So I am following the examples... I have written a script to decode some data from a file, and I want to plot it as a x-y graph (x=time, y = temperature, wind or humidity)- 1440 time steps = 1 minute data for 24 hours. I can do it as a matplotlib graph in the console. I want to develop a ui app with buttons to switch y, with two sliders to control the end time (say 8pm) and duration of the plot (previous one or two hours). So I've used the graphical interface to create the UI, able to control the time/duration and parameters with sliders and buttons respectively...but the graph shows up in the console - I thought of somehow creating a png file on disk, read it up and then somehow display in the imageview window - but I can't seem to find how to do that - I can display an icon from the ui list but not my own graph or image... any hints. Attached is my script - not the most efficient, just trying to learn how to display in imageview window (or any other window)....the ??? shows where i am stuck ???

# wxtui
# A simple RGB color mixer with three sliders.

import ui
import clipboard
from random import random
from console import hud_alert
import os
import re
import console
import matplotlib.pylab as plt

global endTime, duration, wxt520Time, wxt520Data, nparm, parm

endTime=242
duration=120
wxt520Time=[]
wxt520Data=[]
# interactive wxt520 plot


def get_num(s):
    return float( ''.join( x for x in s if x.isdigit() or x == '.') )
  
def getWxt520Data():

    cwd = os.getcwd()
    print cwd

    list = os.listdir(cwd)
    print list

    files=[]
    for f in list:
        if re.match("WXT",f):
            files.append(f)
    print files

    f = files[1]
    fn = open(f,"r")
    lines = fn.readlines()

    date=[]
    time=[]
    count=[]
    data=[]
    for line in lines:
        parts = re.split(' ',line)
        date.append(parts[0])
        time.append(parts[1])
        count.append(parts[2])
        data.append(parts[3])

#create dictionary from data   key:index (location of element to plot)
    dict_index2parameter={}
    dict_parameter2index={}
    parts = re.split(',',data[0])
    lp = len ( parts )
    for i in range(lp):
        if re.search('=',parts[i]):
            q = re.split("=",parts[i])
            dict_parameter2index[q[0]]=i
            dict_index2parameter[i]=q[0]

    print dict_parameter2index
    print dict_index2parameter

# create decimal time
    dtime=[]
    for t in time:
        parts = re.split(':',t)
        d     = float( parts[0] ) + float( parts[1] )/60. + float( parts[2])/3600.   # decimal time
        dtime.append(d)
    return dtime,data,dict_index2parameter,dict_parameter2index 

def extractWxt520Parm(data,nparm):  
    
# extract data
#   nparm = 4   # parameter to display
    y = []
    for d in data:
        parts = re.split(',',d)
        y.append(get_num(parts[nparm]))
    return y

def extractWxt520Subinterval(endtime,duration,dtime,parm):
    iend = 60*endtime
    istart = iend - duration
    if istart <0:
        istart = 0;
        iend   = duration
    if iend > 1440:
        iend = 1439
        istart = iend - duration
    x=dtime[istart:iend]
    y=parm[istart:iend]
    return x,y
    
    
def pltwxt520(x,y):
    plt.grid()
    plt.plot(x,y)
    plt.save("wxt520.png",'PNG')   #??? save the file to disk
#   plt.show()

def button1(sender):
    global wxt520Data, wxt520Time,nparm, parm
    # Get the root view:
    v = sender.superview
    nparm = 7
    parm = extractWxt520Parm(wxt520Data,nparm)
    v['label2'].text = 'fn = '+str(nparm)
    x,y = extractWxt520Subinterval(end,dur,wxt520Time,parm)
    pltwxt520 (x,y)

def button2(sender):
    global wxt520Data, wxt520Time,nparm, parm
    # Get the root view:
    v = sender.superview
    nparm = 4
    parm = extractWxt520Parm(wxt520Data,nparm)
    v['label2'].text = 'fn = '+str(nparm)
    x,y = extractWxt520Subinterval(end,dur,wxt520Time,parm)
    pltwxt520 (x,y)

def button3(sender):
    global wxt520Data, wxt520Time,nparm,parm
    # Get the root view:
    v = sender.superview
    nparm = 9
    parm = extractWxt520Parm(wxt520Data,nparm)
    v['label2'].text = 'fn = '+str(nparm)
    x,y = extractWxt520Subinterval(end,dur,wxt520Time,parm)
    pltwxt520 (x,y)


def slider_action(sender):
    global wxt520Data, wxt520Time,nparm,parm
    # Get the root view:
    v = sender.superview
    # Get the sliders:
    end = int( v['endtime'].value * 24 )
    dur = int ( v['duration'].value * 120 )
    # Create the new color from the slider values:
#   v['view1'].background_color = (r, r*0.1, r*0.23)
    v['label1'].text = 'End Time [h] = '+str(end)+'  Duration [m] = '+str(dur)      
    v['label2'].text = 'fn = '+str(nparm)
#   print end, dur
    x,y = extractWxt520Subinterval(end,dur,wxt520Time,parm)
    pltwxt520 (x,y)
#   img = image.load("wxt520.png")                            # ??? I am stuck here, at this point, I have image on console, image on disk but no image in my imageview1 ui element
#   v['imageview1'].image = img #.named("wxt520.png") 


def main():

    global wxt520Time, wxt520Data, nparm, parm
    
    time, data, dict1, dict2 = getWxt520Data()

    nparm=4
    parm = extractWxt520Parm(data,nparm)
    endTime = 24
    duration = 120
    wxt520Time = time
    wxt520Data = data
#   print wxt520Data
    
    x,y = extractWxt520Subinterval(endTime,duration,time,parm)
#   print x
#   print y
    v = ui.load_view('wxtuiplot')
    slider_action(v['endtime'])

    if ui.get_screen_size()[1] >= 768:
        # iPad
        v.present('fullscreen')
    else:
        # iPhone
        v.present()

main()

Apologies for delay in response - I did not expect such rapid response. This is great.

I had bashed my head too much on that before posting and then started working/learning to do other pythonista stuff.

1. Re OMZ Feb 8 reply. It worked, now to make it really work. Thanks a lot. After bashing hard on it, I shifted to another python. I picked this up again and was just reading about ui and context etc got all confused. Really great. As usual, so close and yet so far.

2. re Gerzer comment. Apologies. Last time in Editorial.

3. re CCC... thanks, this was not production quality code and was trying to learn MPL, ui, etc all at the same time. One of the first things I did was try to snoop around the ipad and realize that I can write only into my own directory. (Maybe others like photos but not there yet.) Your additions are great. I've leaned a bunch of stuff and hopefully I can streamline this code.