Data analysis workflow

[Matteo]

@ccc Hi, thanks but it doesn't work, I have the error (python 2.7):

wss://sagecell.sagemath.org/kernel/33a8268c-e16a-4a5b-84f2-f8ec530ea63a/
Traceback (most recent call last):
  File "SageMathCell - example with 'desolve_odeint' from sagemath.py", line 148, in <module>
    data = a.execute_request(string_for_SageMathCell)['channel']['content']['text']
KeyError: 'channel'

Can you please give me some info about your code? I have added it in place of

pprint.pprint(a.execute_request(string_for_SageMathCell))

I've seen that the output is related to the word "stdout", so I will try to search this text and to print into the python shell (maybe I will need regex).
Thanks again for your time.
Matteo

[JonB]

I think he probably meant iopub instead of channel (i think your output example was misformatted).

Once you get the text key, This appears to be json, you likely want to use json.loads on the textified arrays to get lists of lists -- any then pass to numpy.array() to turn into something useable as a numpy array (for plotting in matplotlib, etc)

[ccc]

@Matteo First start with data = a.execute_request(string_for_SageMathCell) # now you have the data and can play around with it
Then do type(data) # hopefully dict. If it's a str then follow @JonB advice: data = json.loads(data)
Then do data.keys() # hopefully 'content' but whatever it is, go with it...
Now walk down the tree...
Then do type(data['content']) # hopefully still dict
Keep repeating that loop until you get to data...['text'] and then
Follow @JonB advice and data = json.loads(data[x][y][z]['text']) # get rid of the junk you don't care about

Tell us where you get to.

[Matteo]

Hi JonB and ccc, thanks for your post, two days ago I didn't know anything about json, now I know what it is but I can't work/play with it, sorry, I will study further. For now I have a working script that convert the full output into a array or matrix for numpy ( also scalars).

"""
A small client illustrating how to interact with the Sage Cell Server, version 2

Requires the websocket-client package: http://pypi.python.org/pypi/websocket-client
"""

import websocket
import json
import requests

import numpy as np
import re


class SageCell(object):

    def __init__(self, url, timeout=10):
        if not url.endswith('/'):
            url += '/'
        # POST or GET <url>/kernel
        # if there is a terms of service agreement, you need to
        # indicate acceptance in the data parameter below (see the API docs)
        response = requests.post(
            url + 'kernel',
            data={'accepted_tos': 'true'},
            headers={'Accept': 'application/json'}).json()
        # RESPONSE: {"id": "ce20fada-f757-45e5-92fa-05e952dd9c87", "ws_url": "ws://localhost:8888/"}
        # construct the websocket channel url from that
        self.kernel_url = '{ws_url}kernel/{id}/'.format(**response)
        print self.kernel_url
        websocket.setdefaulttimeout(timeout)
        self._ws = websocket.create_connection(
            self.kernel_url + 'channels',
            header={'Jupyter-Kernel-ID': response['id']})
        # initialize our list of messages
        self.shell_messages = []
        self.iopub_messages = []

    def execute_request(self, code):
        # zero out our list of messages, in case this is not the first request
        self.shell_messages = []
        self.iopub_messages = []

        # Send the JSON execute_request message string down the shell channel
        msg = self._make_execute_request(code)
        self._ws.send(msg)

        # Wait until we get both a kernel status idle message and an execute_reply message
        got_execute_reply = False
        got_idle_status = False
        while not (got_execute_reply and got_idle_status):
            msg = json.loads(self._ws.recv())
            if msg['channel'] == 'shell':
                self.shell_messages.append(msg)
                # an execute_reply message signifies the computation is done
                if msg['header']['msg_type'] == 'execute_reply':
                    got_execute_reply = True
            elif msg['channel'] == 'iopub':
                self.iopub_messages.append(msg)
                # the kernel status idle message signifies the kernel is done
                if (msg['header']['msg_type'] == 'status' and
                    msg['content']['execution_state'] == 'idle'):
                        got_idle_status = True

        return {'shell': self.shell_messages, 'iopub': self.iopub_messages}

    def _make_execute_request(self, code):
        from uuid import uuid4
        session = str(uuid4())

        # Here is the general form for an execute_request message
        execute_request = {
            'channel': 'shell',
            'header': {
                'msg_type': 'execute_request',
                'msg_id': str(uuid4()), 
                'username': '', 'session': session,
            },
            'parent_header':{},
            'metadata': {},
            'content': {
                'code': code, 
                'silent': False, 
                'user_expressions': {
                    '_sagecell_files': 'sys._sage_.new_files()',
                }, 
                'allow_stdin': False,
            }
        }
        return json.dumps(execute_request)

    def close(self):
        # If we define this, we can use the closing() context manager to automatically close the channels
        self._ws.close()

if __name__ == "__main__":
    import sys
    if len(sys.argv) >= 2:
        # argv[1] is the web address
        url = sys.argv[1]
    else:
        url = 'https://sagecell.sagemath.org'
    a = SageCell(url)
    import pprint


###############################################

string_for_SageMathCell = """

### SageMath - ODE System Solver:

import numpy as np

# Parameters:
t_begin  =  0
t_end    =  5
step     =  0.05
h , g    =  var(' h , g ')
t        =  var(' t ')


# ODEs and ICs:
  # 'dhdt=g-t-2' et
  # 'dgdt=h+g+t' with
  # 'h(t=0)=1' et
  # 'g(t=0)=3'
functions   =  [ h , g ]
indep_var   =  t
system      =  [ g-t-2 , h+g+t ]
init_conds  =  [ 1 , 3 ]


# Solver:
time_interval  =  srange(t_begin, t_end+step, step)
solution       =  desolve_odeint(system, init_conds, time_interval, functions, indep_var)


# Output matrix:
number_of_steps       =  Integer((t_end-t_begin)/step)+1
time_interval_Matrix  =  np.reshape(time_interval, (1, number_of_steps))
solution_t_functions  =  np.concatenate((time_interval_Matrix.T, solution), axis=1)

print(solution_t_functions)

"""
###############################################

#pprint.pprint(a.execute_request(string_for_SageMathCell))


#### use of regex to parse fullstring

data = a.execute_request(string_for_SageMathCell)

fulltext = str(data)

pattern = "(?<={u'text': u').*?(?=', u'name': u'stdout'})"

ls = re.findall(pattern, fulltext, re.DOTALL)

sage_output = str(ls[0])

sage_output_1 = sage_output.replace(r'\n', ',')

pattern = "(?<=\d)\s?(?=\s)"

sage_output_2 = re.sub(pattern, ',', sage_output_1)

sage_output_3 = eval(sage_output_2)

var1 = np.array(sage_output_3)

print(var1+1) # this is only to prove that var1 is ok for numpy

I've used regex, and massive stackoverflow.com surfing (without it I cant write more than 2-3 rows of code in python when I must work with strings and other python objects different from numbers and arrays).

I have some little ideas to increase the use of the script. I will write here in the next days.

Thanks for your help

Regards
Matteo

[Matteo]

Hi, some ideas for the script above that could help people in math calculations using Pythonista linked to Internet:

• goal: to give more power to Pythonista about math coding with python (built-in mpmath, sympy, numpy and matplotlib are ok but not updated and too poor for the following numerical computations with existing and tested algorithms: ODE, PDE, System of big linear and nonlinear equations, numerical fitting of ndimensional functions with data, etc...).

• problems with the above script:

  1. it must be improved to parse different types of output objects (strings) provided by SageMathCell : working on it.
  2. it must be improved to return, as text, any errors found by SageMathCell (for example if in the variable 'string_for_SageMathCell' there are some syntax errors, the script should return, in Pythonista shell , the same error that user can read when he uses the https://sagecell.sagemath.org/ service with any internet browsers): working on it.
  3. a big limit of the above script with Pythonista, in my opinion, is the lack of syntax checking and powerful word completion provided by the IDE inside the code between """ """, that is the code that is send to SageMathCell server: for now I have no idea to solve this.

• as an example, the kind of math environment I'd like to have with Pythonista and SageMathCell (that could become a CoCalc account for more power) is the hypothetical following python script:

#!python2

print('Lets try a SageMathCell session with Pythonista')


##comment: with '#!sage' user could start a SageMath session inside the powerful Pythonista Editor, in the same way '#!python2' forces the interpreter to run with python 2.x instead of 3.x.

#!sage

import numpy as np

# Parameters:
t_begin  =  0
t_end    =  5
step     =  0.05
h , g    =  var(' h , g ')
t        =  var(' t ')


# ODEs and ICs:
  # 'dhdt=g-t-2' et
  # 'dgdt=h+g+t' with
  # 'h(t=0)=1' et
  # 'g(t=0)=3'
functions   =  [ h , g ]
indep_var   =  t
system      =  [ g-t-2 , h+g+t ]
init_conds  =  [ 1 , 3 ]


# Solver:
time_interval  =  srange(t_begin, t_end+step, step)
solution       =  desolve_odeint(system, init_conds, time_interval, functions, indep_var)


# Output matrix:
number_of_steps       =  Integer((t_end-t_begin)/step)+1
time_interval_Matrix  =  np.reshape(time_interval, (1, number_of_steps))
solution_t_functions  =  np.concatenate((time_interval_Matrix.T, solution), axis=1)


##comment: 'savesage' could be a new command to save into an internal Pythonista variable the output of the server to use it later for plotting or for other further analysis; the 'variable_for_Pythonista' should be any object known by Pythonista and by all its built-in libraries (numpy arrays, numbers, etc...). 'savesage' could extract the output of the calculation provided by SageMathCell and save it in the 'variable_for_Pythonista' variable.

savesage(solution_t_functions, variable_for_Pythonista)


##comment: with '#!endsage' user could go out from SageMath syntax (that is very similar to python syntax) and could return to Pythonista environment.

#!endsage

print(variable_for_Pythonista) #The variable 'variable_for_Pythonista' now is supposed to be fully readable by Pythonista in order to use it with any its built-in libraries.

As you have seen, my programming approach is very basic and procedural, I have very little knowledges in Object-oriented programming; for this reason, the script enhancements could be very little.

Thanks
Matteo

[JonB]

It seems to me that to truly handle variable saving, you need to use someing like pickle or, yaml, etc that can serialize arbitrary objects (say, a dict of results), which then gets printed, along with some tag that can be easily searched, and then unpickled to current workspace. I am not sure how robust pickle will be to unpickling objects from a different version of python, environment, etc. numpy.save to a StringIO could also work.

As for syntax checking, etc, I wonder if what you want is a wrench action which takes the current script in the pythonista editor, sends it to sage, and shows the output in a textview in a panel. That way you just write normal python, then hit the wrench button, and at least can see the output.

[JonB]

okay, i have not converted to a wrench script yet, but here is something that:

• lets you save variables using np.savez, and these are transferred directly to globals locally.
• images are transferred and shown in console.
  errors and text are split up --probably need to grab traceback too, and maybe raise error directly.
  https://gist.github.com/b72236f268f706e84d493cb67944e0e7

no.savez does support regular python variables, however some of these seem to end up as sage types (sage.rings.integer), so they are not directly importable. So, if that is desirable, it may be necessary to use a different mechanism, like casting to standard types first.

[JonB]

https://gist.github.com/dae885cd334bca0bd80ee0132978fc50

and now as a wrench action -- add this to your wrench actions, then run wrench on a script.
errors get highlighted in the script, and traceback printed to console.
printed text is printed to console, and images are shown in console.
variables saved as npz files are loaded into globals() of the 2.7 interpreter . This works for numpy arrays, and probably would work for raw literals (i.e x=1r instead of x=1, which is how sage denotes raw literals instead of sage rings)

[Matteo]

@JonB Hi JonB, your code is simply Amazing! Thank you very much for sharing it! I will use it for any calculations to learn advanced math coding with Python+Sage.

Best regards,
Matteo

[Matteo]

Hi JonB, feel free to answer: do you think it would be too hard to modify your script in order to use it not only like a wrench but also like a function inside any Pythonista script that can be executed with the classical |> (run) button?
For example, let's imagine I have a folder inside Pythonista in which I have my script for SageMath server, named it 'ODE Solver.py' (the one between """ """ in the above posts) and a different script that could be as follow:

#!python2

import numpy as np

print('this print is performed by Pythonista built-in core ...')

print('... and now we use the SageMath server to run a script (ODE Solver.py) that performs advanced math calculations and that could be written/coded programmatically and/or automatically by a suitable script that uses only Pythonista built-in libraries')

variable_1 = sage_interface('ODE Solver.py')

print('now  we have created a new variable that we can use inside this Pythonista script')

print(variable_1)

print('if variable_1 is a numpy object, NxM array or real/complex number, we could perform further calculations on it with Pythonista or yet with SageMath server, if variable_1 is a string, that is any error output by SageMath, any further calculation on the variable could return the SageMath error message.')

I don' know if your 'sage_interface.py' should be placed inside any reserved folder of Pythonista in order to use it like a function (sage_interface('any_sagemathcell_script.py')).

What do you think?
Thanks again!
Best regards

Matteo

[Matteo]

Hi, the following is a script that tries to perform some tasks of my previous post (Sorry for the long post, I will create a cloud link for the scripts):

"""
A small client illustrating how to interact with the Sage Cell Server, version 2

Requires the websocket-client package: http://pypi.python.org/pypi/websocket-client
"""

import websocket
import json
import requests
import re
import numpy as np
np.set_printoptions(threshold=np.inf)


global server_timeout
server_timeout = None

class SageCell(object):

    def __init__(self, url, timeout=server_timeout):
        if not url.endswith('/'):
            url += '/'
        ## POST or GET <url>/kernel
        ## if there is a terms of service agreement, you need to
        ## indicate acceptance in the data parameter below (see the API docs)
        response = requests.post(
            url + 'kernel',
            data={'accepted_tos': 'true'},
            headers={'Accept': 'application/json'}).json()
        ## RESPONSE: {"id": "ce20fada-f757-45e5-92fa-05e952dd9c87", "ws_url": "ws://localhost:8888/"}
        ## construct the websocket channel url from that
        self.kernel_url = '{ws_url}kernel/{id}/'.format(**response)
        #print self.kernel_url
        websocket.setdefaulttimeout(timeout)
        self._ws = websocket.create_connection(
            self.kernel_url + 'channels',
            header={'Jupyter-Kernel-ID': response['id']})
        ## initialize our list of messages
        self.shell_messages = []
        self.iopub_messages = []

    def execute_request(self, code):
        ## zero out our list of messages, in case this is not the first request
        self.shell_messages = []
        self.iopub_messages = []

        ## Send the JSON execute_request message string down the shell channel
        msg = self._make_execute_request(code)
        self._ws.send(msg)

        ## Wait until we get both a kernel status idle message and an execute_reply message
        got_execute_reply = False
        got_idle_status = False
        while not (got_execute_reply and got_idle_status):
            msg = json.loads(self._ws.recv())
            if msg['channel'] == 'shell':
                self.shell_messages.append(msg)
                ## an execute_reply message signifies the computation is done
                if msg['header']['msg_type'] == 'execute_reply':
                    got_execute_reply = True
            elif msg['channel'] == 'iopub':
                self.iopub_messages.append(msg)
                ## the kernel status idle message signifies the kernel is done
                if (msg['header']['msg_type'] == 'status' and
                    msg['content']['execution_state'] == 'idle'):
                        got_idle_status = True

        return {'shell': self.shell_messages, 'iopub': self.iopub_messages}

    def _make_execute_request(self, code):
        from uuid import uuid4
        session = str(uuid4())

        ## Here is the general form for an execute_request message
        execute_request = {
            'channel': 'shell',
            'header': {
                'msg_type': 'execute_request',
                'msg_id': str(uuid4()), 
                'username': '', 'session': session,
            },
            'parent_header':{},
            'metadata': {},
            'content': {
                'code': code, 
                'silent': False, 
                'user_expressions': {
                    '_sagecell_files': 'sys._sage_.new_files()',
                }, 
                'allow_stdin': False,
            }
        }
        return json.dumps(execute_request)

    def close(self):
        ## If we define this, we can use the closing() context manager to automatically close the channels
        self._ws.close()



## Function that we can use inside any Pythonista script with the import 'from sage_interface import *':
def execute_sage(filename, server_timeout):
	import sys
	if len(sys.argv) >= 2:
		## argv[1] is the web address
		url = sys.argv[1]
	else:
		url = 'https://sagecell.sagemath.org'
	
	file = open(filename, 'r')
	string_to_sage = file.read()
	file.close()
	
	try:
		a = SageCell(url, server_timeout)
		data = a.execute_request(string_to_sage)
	except:
		print("Can't finish the calculation. Try to increase the timeout parameter of the function 'execute_sage(filename, timeout)' for the script to be processed.")
		sys.exit()

	
	## let's prettyprint the full output by SageMathCell server:
	#import pprint
	#file_output = open("sage_interface.out", 'w')
	#file_output.write(pprint.pformat(data))
	#file_output.close()
	
	data_string = str(data)
	## let's search for 'stdout' in 'data_string' (to find SageMathCell errors):
	ls = data_string.find('stdout')
	if ls == -1:
		print("There are some syntax errors in the sourcecodes passed to SageMathCell server: check them.")
		sys.exit()

	## if 'ls = -1' it means that there is an error in the source passed to remote server, in all other cases let's look for a warning message, if it exists, inside 'data_string' (to find SageMathCell warning):
	ls = data_string.find('stderr')
	if ls == -1:   ## there is not warning by SageMathCell, so let's find the numerical output inside 'data_string' (what we need, that is any real or complex NxM array or number):
		pattern = "(?<={u'text': u').*?(?=', u'name': u'stdout'})"
		ls = re.findall(pattern, data_string, re.DOTALL)[0]
		ls = ls.replace(r'\n', ',')
		pattern = "(?<=\d)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)
		## let's add parsing for complex numbers and arrays:
		pattern = "(?<=j)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)
		## let's solve error parsing for arrays numbers like 1.:
		pattern = "(?<=\.)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)

		try:		
			output = np.array(eval(ls))
		except:
			print('Output unrecognized by Pythonista numpy. For now it is possible to use/view only numpy real/complex NxM arrays or numbers.')
			sys.exit()
			
	else:   ## there is a sage warning, let's find and print it in the console:
		pattern = "(?<={u'text': u').*?(?=, u'name': u'stderr'})"
		ls = re.findall(pattern, data_string, re.DOTALL)[0]
		ls = ls.replace(r"\n'",'')
		ls = ls.replace(r'\n','\n')
		print(ls)
		## now find the numerical output (any real or complex NxM array or number):
		pattern = "(?<={u'text': u').*?(?=', u'name': u'stdout'})"
		ls = re.findall(pattern, data_string, re.DOTALL)[0]
		ls = ls.replace(r'\n', ',')
		pattern = "(?<=\d)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)
		pattern = "(?<={u'text': u').*(?=)"
		ls = re.findall(pattern, ls, re.DOTALL)[0]
		## let's add parsing for complex numbers and arrays:
		pattern = "(?<=j)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)
		## let's solve error parsing for arrays numbers like 1.:
		pattern = "(?<=\.)\s?(?=\s)"
		ls = re.sub(pattern, ',', ls)
		
		try:		
			output = np.array(eval(ls))
		except:
			print('Output unrecognized by Pythonista numpy. For now it is possible to use/view only numpy real/complex NxM arrays or numbers.')
			sys.exit()
	
	return output

If you want, try to name it 'sage_interface.py' and save it in a folder (let's name the folder 'sage_test').

Then, in folder 'sage_test', save the following script (the usual), giving it a name, let's say 'input_sage_03.py' (it is the full script that is passed to SageMathCell):

### SageMath - ODE System Solver:

import numpy as np
np.set_printoptions(threshold=np.inf)

# Parameters:
t_begin = 0
t_end   = 10
step    = 0.1
h , g   = var(' h , g ')
t       = var(' t ')

# ODEs and ICs:
  # 'dhdt=g' et
  # 'dgdt=-h' with
  # 'h(t=0)=1' et
  # 'g(t=0)=1'
functions  = [ h , g ]
indep_var  = t
system     = [ g , -h ]
init_conds = [ 1 , 1 ]

# Solver:
time_interval = srange(t_begin, t_end+step, step)
solution      = desolve_odeint(system, init_conds, time_interval, functions, indep_var)

# Output matrix:
number_of_steps       = Integer((t_end-t_begin)/step)+1
time_interval_Matrix  = np.reshape(time_interval, (1, number_of_steps))
solution_t_functions  = np.concatenate((time_interval_Matrix.T, solution), axis=1)
print(solution_t_functions)

Finally, save, always in folder 'sage_test', the following main script with a name, let's say 'sage_test_03.py':

## For now this script can execute only independent scripts, that is: the output of a script executed by SageMathCell through the function 'execute_sage(filename, timeout)' can't be passed to the input for the next script executed by SageMathCell.
## Working on it to pass, easly, input-output from/for Sage server and Pythonista.

from sage_interface import *

import time
import numpy as np
np.set_printoptions(threshold=np.inf)
import matplotlib.pyplot as plt


## third script = 'input_sage_03.py' : execute_sage(full-filename, timeout_in_seconds)
output_03 = execute_sage('input_sage_03.py', 1)   ## script executed by Sage remote server
print(output_03+100)   ## command executed by Pythonista (local Python core)
print(output_03+(120+180.j))   ## to check the compatibility with the built-in Pythonista numpy v1.8.0
print('-----------------------')

output_03_mod = output_03 * (1)   ## command executed by Pythonista (local Python core), like the following ones:
print(output_03_mod)
plt.suptitle("Solutions for h (green) and g (red) by processed script 'input_sage_03.py'", fontsize=14, fontweight='bold')
plt.plot(output_03_mod[:,0], output_03_mod[:,1], color='g')   ## plot h(t)
plt.plot(output_03_mod[:,0], output_03_mod[:,2], color='r')   ## plot g(t)
plt.xlabel('time (s)', fontsize=12, fontweight='bold')
plt.ylabel('h, g', fontsize=12, fontweight='bold')
plt.show()
print('-----------------------')

If you execute the script 'sage_test_03.py' with Pythonista, it should return the wanted output (some arrays and a plot created with built-in matplotlib inside Pythonista).

Working to improve 'sage_interface.py'.

Thanks to Andrey Novoseltsev and co for SageMathCell, JonB and ccc for suggestions, JonB for the wrench version of sage_interface for Pythonista, omz for Pythonista.

I hope this could help people with math.

Regards
Matteo

[Matteo]

Hi, some news about 'sage_interface.py' (useful for me, I don't know if for you too):

• here you find version dated 15-09-2017 (previous post) of 'sage_interface.py';

• here you find version 29-09-2017, the new one, with some improvements.

Modify the scripts as you want to perform your calculations.
The script 'sage_interface.py' can be greatly improved to facilitate the use of the server.

Bye
Matteo

PS: if you want, use this script 'file_downloader.py' to download any zipped folder from any shared Google Drive folder with specific ID (this script is adapted for the two folders I shared in this post):

#!python2

import urllib

url = "https://drive.google.com/uc?export=download&id=11vXOY7o3YPK2DkH6_p9e0F94LSiylydO"
filename = "sage_interface 2017-09-15.zip"
urllib.urlretrieve(url, filename)


url = "https://drive.google.com/uc?export=download&id=1bdEHQjYEkxEtwgrhpSiUnOfOBItbtE3-"
filename = "sage_interface 2017-09-29.zip"
urllib.urlretrieve(url, filename)

[ihf]

@Matteo I noticed that the plt commands in the first input file are commented out. I tried uncommenting but it did not seem to have any effect. Is plotting working?

[Matteo]

@ihf Hi. There are two version of sage_interface:

1. JonB wrench version: it works with plot via the command 'plt.savefig('filename.png')' instead of the common 'plt.show()', but this trick works with the very first plot call. Try to change 'plt.show()' with 'plt.savefig(filename.png)' and uncomment it. Run the script with the wrench version of sage_interface: it should return the plot and the very first printed array. But about the wrench version you should ask to JonB because it uses some Python/Pythonista pieces of code that I don't know (sorry).
2. Function version (my simple implementation for my own purposes): it works with several scripts and with a very simple variables input from Pythonista to server (see function 'execute_script_w_inputs') but the output is a list of strings (a string for each print command in the script passed to server) and you need to evaluate what you want, no plot for now, sorry.

Feel free to try to improve the code in order to obtain several plots with the sage_interface version that you use.
Thanks
Bye

[Matteo]

Hi, some news about 'sage_interface.py':

1. here you find version dated 25-10-2017 of 'sage_interface.py'.

Added plot capability.
Bye

[Matteo]

Hi, some news about 'sage_interface.py':

1. here you find version dated 20-11-2017 of 'sage_interface.py'.

Added basic error checking and device online checking.

Bye

Edit: I've reload the scripts because I've modified 'sage_interface.py' a little: I've changed a regex pattern in 'process_data'.

Future possible improvements:

1. to write a robust routine to convert string type arrays to numpy type arrays ([ [ 1 2 ] [ 3 4 ] ] ===> [ [ 1, 2], [3, 4 ] ])
2. to create a set of scripts (recipes) to perform easly some math numerical computations with scipy library (only the inputs in the main script need to be modified, the scripts like 'input_sage_XX.py' don't need to be modified.
   Thanks
   Bye

[Matteo]

Hi, here you find version 27-12-2017 of 'sage_interface'.
Added string to numpy array conversion and some little improvements.

Feel free to propose improvements or changes to the code.
Have you good end and good beginning for the new year!
Bye