## Login and archival of results

Parampool has a feature that allows a user to create an account, log in, and save the results from simulations. The results of a run consists of the HTML code and plots, which are stored in a database. Later, old results can be retrieved in the GUI. Enabling login is just a matter of writing enable_login=True in the call to the generate function:

from parampool.generator.flask import generate
from compute import compute_motion_and_forces

generate(compute_motion_and_forces, MathJax=True,


The generated controller.py file is now much more complicated in the Flask case, but the details are not important for the plain user of Parampool. The usage should be explanatory: first click on Register to register a new user, later one can just click on Login. After having run a simlation, a Comments field arises where one can add comments about this run, and then click on Add if the results are sufficiently interesting to be stored in the database. The upper right corner has a link Previous simulations which gives access to previous results in the database. At the bottom of the page with previous runs, there is a Delete all button that clears the database.

### Problems with sending email

In case of error messages regarding sending email through Google's server, it may help to add the following line to controller.py, e.g., right before the send_email function:

app.config['MAIL_SERVER'] = 'smtp.gmail.com'


## Python expressions as input

One can use Python expressions like sin(0.5)*exp(-1) in the input fields. Parampool will recognize arithmetic expressions or use of mathematical functions, and in such cases run eval on the input to interpret it. If special functions are needed, e.g., the input is like myfunc(0.1), one can supply a namespace to the data item in question through the namespace parameter. Here we create a custom namespace for a parameter, where the namespace includes myfunc from mymodule and all functions (or more precisely, all names) in yourmodule that do not start with an underscore:

import mymodule, yourmodule
namespace = {'myfunc': mymodule.myfunc}
namespace.update({key: value for key, value in
yourmodule.__dict__.iteritems()
if not key.startswith('_')}