MBGMODEL(1)

💖 MBGMODEL — the MBGMODEL(1) page, bestie edition 💖

okay so. hi. you're looking at the Montage page for mBgModel, and honestly? this one's a baddie. buckle up. 🎀

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✨ NAME ✨

mBgModel — Re-project and mosaic your images, with background rectification 🦋

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✨ SYNOPSIS ✨

mBgModel [-i niter] [-l(evel-only)] [-d level] [-r refimg] [-s
statusfile] images.tbl fits.tbl corrections.tbl

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✨ DESCRIPTION ✨

mBgModel is a modelling/fitting program. It takes the image-to-image difference parameter table that mFitExec made, and then it interactively figures out a set of corrections to slap onto each image so you get a "best" global fit. like, it's out here doing the math so your mosaic doesn't look a mess. no cap. 💅

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✨ OPTIONS ✨

• -i, -niter — number of iterations. (without the switch it defaults to 5000.) can be anywhere between 1 and 32767.
• -l — calculate level adjustments only (ie, don't attempt to match the slopes). lowkey the safe option, remember this one.
• -d level — turns on debugging to the specified level (1-3).
• -r refimg — turns on additional debugging for the *n*th image in images.tbl.
• -a — use all the input differences (by default we exclude very small overlap areas). 🙈
• -s statusfile — mBgModel output and errors are written to statusfile instead of to stdout.

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✨ ARGUMENTS ✨

• images.tbl — Image metadata table generated by mImgtbl. 🧚
• fits.tbl — Plane fitting table generated by mFitExec.
• corrections.tbl — Output table of background corrections. this is the one you actually came for, bestie. 💖

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✨ RESULT ✨

Output table containing corrections to be applied to each image. periodt.

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✨ MESSAGES ✨

the whole group chat of things it can say to you, verbatim, no edits:

OK     [struct stat="OK"]

ERROR  Argument for -i (string) cannot be interpreted as an integer

ERROR  Number of iterations too small (niter). This parameter is
       normally around 5000.

ERROR  Argument for -r (string) cannot be interpreted as an integer

ERROR  Cannot open status file: statusfile

ERROR  Failed to open output filename

ERROR  Invalid image metadata file: filename

ERROR  Need columns: cntr nl ns crpix1 crpix2 in image info file

ERROR  malloc() failed (ImgInfo)

ERROR  realloc() failed (ImgInfo)

ERROR  Invalid background fit parameters file: filename

ERROR  Need columns: plus minus a b c crpix1 crpix2 xmin xmax ymin ymax
       xcenter ycenter npixel rms boxx boxy boxwidth boxheight boxang

ERROR  malloc() failed (FitInfo)

ERROR  realloc() failed (FitInfo)

ERROR  malloc() failed (CorrInfo)

ERROR  realloc() failed (CorrInfo)

ERROR  Debug reference image out of range (0 - n)

ERROR  Invalid fit type

ERROR  Allocation failure in ivector()

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✨ EXAMPLES ✨

so after you run mDiffExec to create a set of difference images in diffdir, we generate an image difference table using mFitExec: sample fits.tbl.

$ mBgModel images.tbl fits.tbl corrections.tbl
       [struct stat="OK"]

this results in the creation of corrections.tbl. iconic behaviour, honestly. 🌈

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✨ BUGS ✨

The drizzle algorithm has been implemented but has not been tested in this release. 💀

If a header template contains carriage returns (i.e., created/modified on a Windows machine), the cfitsio library will be unable to read it properly, resulting in the error:

[struct stat="ERROR", status=207, msg="illegal character in keyword"]

It is best for the background correction algorithms if the area described in the header template completely encloses all of the input images in their entirety. If parts of input images are "chopped off" by the header template, the background correction will be affected. We recommend you use an expanded header for the reprojection and background modeling steps, returning to the originally desired header size for the final coaddition.

The default background matching assumes that there are no non-linear background variations in the individual images (and therefore in the overlap differences). If there is any uncertainty in this regard, it is safer to turn on the "level only" background matching (the "-l" flag in mBgModel).

okay so that last one is genuinely important — if you're not sure, just use -l. fr fr.

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✨ COPYRIGHT ✨

2001-2015 California Institute of Technology, Pasadena, California

If your research uses Montage, please include the following acknowledgement: "This research made use of Montage. It is funded by the National Science Foundation under Grant Number ACI-1440620, and was previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology."

The Montage distribution includes an adaptation of the MOPEX algorithm developed at the Spitzer Science Center.

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and that's the whole thing, bestie 🫶 this was Montage 5, dated Dec 2016 — main character energy from start to finish. now go fix those backgrounds. you got this. 💜✨👑