dap/CUSTOM_SCRIPTS.md

Custom DAP Scripts

The DAP allows custom scripts to be uploaded and run on the streamed detector data.

Libraries like numpy and scipy are available, further can be added.

Structure

myalgo.py:

def proc(meta, image, mask):
    ...
    return result

or

def myalgo(meta, image, mask):
    ...
    return result

Both function names are allowed. meta is a dict containing all results that have been calculated for this image by other configured algorithms already. Modifications of this dict inside the function are ignored. Instead, all new results should be returned from the function.

result may be either a single value or a dict. A single value will be turned into the channel name detector_name:script_name, e.g. JF01T02V03:myalgo. For a dict, each entry will be turned into a channel of the pattern detector_name:key.

Uploading

For uploading a custom script from slic, use:

daq = SFAcquisition(...)
daq.client.upload_custom_dap_script("myalgo.py")

Alternatively, the "slow broker" endpoint upload_custom_dap_script may be used directly. It expects "name" and "code", which are the script's name and function code as strings, respectively.

The scripts will be stored per beamline. This allows two beamlines to have a script each with the same name. The beamline is determined by the subnet from which the script is uploaded and cannot be manually changed.

Enabling

For enabling a custom script from slic, use:

daq = SFAcquisition(...)
parameters = {
    "custom_script": "beamline:script_name"
}
daq.client.restapi.set_dap_settings(detector, parameters)

Here, beamline can be any beamline, meaning it is possible to use a script from another beamline.

Alternatively, the "slow broker" endpoint set_dap_settings may be used directly. It expects "detector_name" and "parameters" (see example above).