How to replot data from previous scan?

[prjemian]

This is a request from APS 8-ID-I. Others will also ask this.

Make a function: utils.replay(headers, callback=None) that uses bec from the IPython shell as a default callback. Here, headers is either an instance of databroker.Header or a list of those objects.

[prjemian]

The general idea is:

1. get the scan's header (such as h = db[-1] for the previous scan or h = db["abcd1234"] for a scan with uid that starts with abcd1234, there are other ways to get a scan header)
2. play the header's document stream through an appropriate plotting callback

This code plays that header through the BestEffortCallback (many configurable options):

from databroker import Broker
from bluesky.callbacks.best_effort import BestEffortCallback

db = Broker.named("mongodb_config")
bec = BestEffortCallback()

for k, doc in db[-1].documents():
    bec(k, doc)

We use the BestEffortCallback() because it chooses which type of plot to be made based on content in the header (1-D, 2-D, mesh, image, ...) and what signals to use for dependent and independent axes. It's your choice to use a different callback.