[LSST|dm-users 676] How to Use meas_modelfit to Measure Sersic Properties

[Will Dawson]

I am trying to use the DM Stack to measure the Sersic profile of a galaxy in a postage stamp. It looks like meas_modelfit (rather than e.g. meas_base) is what I want since it contains things like:

@registerModel("fixed-sersic")
class FixedSersicModelConfig(FixedSersicConfig):
and
@registerModel("bulge+disk")
class BulgeDiskModelConfig(lsst.pex.config.Config):

But I am not sure how to configure means_modelfit (note that it is installed and I can use eups setup with it just fine). For example, with meas_base I am used to doing something like:

import lsst.meas.base as measBase
import lsst.afw.table as afwTable
schema = afwTable.SourceTable.makeMinimalSchema()
measureConfig = measBase.SingleFrameMeasurementConfig()
measure = measBase.SingleFrameMeasurementTask(config=measureConfig, schema=schema)

Fishing somewhat in the dark I have tried things like subbing in: 
import lsst.meas.modelfit as measModel
measureConfig = measModel.MeasureImageConfig()

But get errors like: 
InvalidParameterError: 
  File "src/table/Schema.cc", line 590, in Key<lsst::afw::table::Flag> lsst::afw::table::detail::SchemaImpl::addField(const Field<lsst::afw::table::Flag> &, bool)
    Field with name 'flags_negative' already present in schema. {0}
lsst::pex::exceptions::InvalidParameterError: 'Field with name 'flags_negative' already present in schema.'

I am hoping that someone more familiar with the meas_modelfit package can help me out with its proper usage, or tell me if I should be using a different package to measure Sersic profiles of postage stamps.

Thank you,
Will



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.lsst.org/pipermail/dm-users/attachments/20150525/06c9aeba/attachment.html>