# DataHandler¶

class do_mpc.sampling.datahandler.DataHandler(sampling_plan)[source]

Post-processing data created from a sampling plan. Data (individual samples) were created with do_mpc.sampling.sampler.Sampler. The list of all samples originates from do_mpc.sampling.samplingplanner.SamplingPlanner and is used to initiate this class (sampling_plan).

Configuration and retrieving processed data:

1. Initiate the object with the sampling_plan originating from do_mpc.sampling.samplingplanner.SamplingPlanner.
2. Set parameters with set_param(). Most importantly, the directory in which the individual samples are located should be passe with data_dir argument.
3. (Optional) set one (or multiple) post-processing functions. These functions are applied to each loaded sample and can, e.g., extract or compile important information.
4. Load and return samples either by indexing with the __getitem__() method or by filtering with filter().

Example:

sp = do_mpc.sampling.SamplingPlanner()

# Plan with two variables alpha and beta:
sp.set_sampling_var('alpha', np.random.randn)
sp.set_sampling_var('beta', lambda: np.random.randint(0,5))

plan = sp.gen_sampling_plan(n_samples=10)

sampler = do_mpc.sampling.Sampler(plan)

# Sampler computes the product of two variables alpha and beta
# that were created in the SamplingPlanner:

def sample_function(alpha, beta):
return alpha*beta

sampler.set_sample_function(sample_function)

sampler.sample_data()

# Create DataHandler object with same plan:
dh = do_mpc.sampling.DataHandler(plan)

# Assume you want to compute the square of the result of each sample
dh.set_post_processing('square', lambda res: res**2)

# As well as the value itself:
dh.set_post_processing('default', lambda res: res)

# Query all post-processed results with:
dh[:]


Attributes

 DataHandler.data_dir Set the directory where the results are stored.

Methods

 DataHandler.filter Filter data from the DataHandler. DataHandler.set_param Set the parameters of the DataHandler. DataHandler.set_post_processing Set a post processing function.