= Frequently Asked Questions : DVO =

==== How do I use the dvo shell, variables, math functions, plotting capabilities etc? ====

`dvo` uses the [wiki:Opihi_Shell_Language Opihi Shell Language] (q.v. for the amazing number of things you can do in it).

==== How do I update the list of photcodes ? ====

Your .ptolemyrc file specifies the location of a `PHOTCODE_FILE` as well as a `CATDIR`, usually with something like:

{{{
 CONFDIR                    /home/panstarrs/ipp/psconfig/ipp-2.6.lin64/share/ippconfig 
 PHOTCODE_FILE		$CONFDIR/dvo.photcodes
 # location of DVO database tables
 CATDIR			/data/ipp003.0/catdir
}}}
If you want to update the photometry codes, you will have to edit that `dvo.photcodes` file or specify the location of a new one. But if you have already created a DVO catdir, then the photcodes are locked in place.  Any dvo programs like addstar or dvo itself will pick up the photcodes from the `Photcodes.dat` file in your `CATDIR`, not from the `PHOTCODE_FILE`.  So after updating your `PHOTCODE_FILE`, you must delete the `Photcodes.dat` file from your `CATDIR`.  Then when you run something like addstar, a new `Photcodes.dat` file will be automatically created.

==== addstar is reporting a "bad astrometric solution in header."  How do I get around that? ====

You probably have an astrometric error term that exceeds the allowable range.   The parameter `ADDSTAR_MAX_CERROR` can be specified in your camera's `dvo.config` file.  Try increasing this parameter.   To change it at the command line you can use :

{{{
 addstar -D ADDSTAR_MAX_CERROR 5.0  ...
}}}
==== After processing a set of overlapping images, there are too many stars in the catalog. What's wrong? ====

You may need to re-sort the dvo catalog.  In the normal camera stage processing, each new photometry file is added to the database without any sorting of detected objects (because this is a time-consuming process).  Use the following to sort your overlapping catalogs and coordinate multiple occurrences of the same object:

{{{
 addstar -resort -D CATDIR mycatdir 
}}}
To specify the radius (in arcseconds) for determining a match, use 

{{{
 addstar -resort -D CATDIR mycatdir -D RADIUS 1.5  
}}}
or edit the appropriate dvo.config file for your camera.

==== I've got a perfectly good .smf file, but I can't see any stars.  What's wrong? ====

You might have an error in your `.ptolemyrc` file.
Compare your `.ptolemyrc` file to the `dvo.site` file from the ipp installation you are using.


==== How do I set up my .ptolemyrc file? ====

Here is an example `.ptolemyrc` that functions with GPC1 data as of ipp-2.6 :

{{{
CONFDIR                 /home/panstarrs/ipp/psconfig/ipp-2.6-bills.lin64/share/ippconfig
CAMERA                  default

# location of DVO database tables
CATDIR			default

# location of possible data sources
2MASS_DIR_AS		NONE
2MASS_DIR_DR2		NONE
GSCDIR			NONE
USNO_A_DIR		NONE
USNO_B_DIR		NONE
TYCHO_DIR		NONE

PHOTCODE_FILE		$CONFDIR/dvo.photcodes
GSCFILE			$CONFDIR/GSCregions.tbl
CATMODE			SPLIT
CATFORMAT		PS1_DEV_1
SKY_DEPTH               3
# SKY_TABLE		this may be used to override GSCFILE
ZERO_PT			25.0

# access control for client/server addstar mode 
# PASSWORD
# HOSTNAME
# VALID_IP

# camera dependent parameter files:
FILTER_LIST             $CONFDIR/$CAMERA/dvo.filters
CAMERA_CONFIG           $CONFDIR/$CAMERA/dvo.layout
DETREND_RECIPES         $CONFDIR/$CAMERA/dvo.recipe

# load the camera-specific configuration files
input                   $CONFDIR/$CAMERA/dvo.config

}}}


==== How can I access info from the mysql database tables within DVO? ====
Use `dbconnect` to connect to the database and `dbselect` to collect the data.

{{{
dvo: dbconnect
USAGE: dbconnect (hostname) (username) (database)

dvo: dbselect
USAGE: dbselect (fields) from (table) [where]
}}}

Here is an example using the '''gpc1''' database that extracts some vectors from the MD09 chip processing output.

{{{
dvo:  dbconnect  hostmachine  uid gpc1
dvo: dbselect chipProcessedImfile.class_id,chipProcessedImfile.fwhm_major,chipProcessedImfile.fwhm_minor,chipProcessedImfile.n_stars,chipProcessedImfile.n_astrom,chipProcessedImfile.sigma_ra,chipProcessedImfile.sigma_dec FROM chipProcessedImfile,chipRun,rawExp  WHERE chipProcessedImfile.chip_id=chipRun.chip_id AND chipRun.exp_id=rawExp.exp_id AND rawExp.ra >= '5.8' AND rawExp.ra <= '5.9' AND rawExp.decl >= '-0.1' AND rawExp.decl <= '0.1' AND rawExp.exp_time>60 AND chipProcessedImfile.fault=0 AND chipRun.state='full'
}}}


==== How do I create/manipulate a vector/array of values? ====
Create vectors from scratch with the `create` function   Example:

{{{
 create x 0 100 0.1 
}}}
creates a vector called x with 100 values spaced in increments of 0.1, starting at 0.

Perform arithmetic, etc. with the `set` function.   Use 

{{{
 help set
}}}
to see detailed help and examples.

==== How do I make a histogram of a vector or an image? ====
The internal dvo documentation (available via `help` or `?`)  is a bit confusing for this.  

`histogram` computes the histogram of a ''vector'' (a list of numbers). 
The usage line for this function should be:
{{{
 USAGE: histogram invec outvec start end [delta]
}}}
`imhist` computes the histogram of an ''image'' 
The usage line should read: 
{{{
 USAGE: imhist <buffer> <x> <y> [-region sx sy nx ny] [-range min max] [-delta binsize]
}}}
'''Ignore the response you get from `help histogram`'''

==== How do I make plots of vectors and how do I set the plotting style? ====
Use the `plot` and `style` functions.  Check out the dvo help pages with:

{{{
 help plot
 
 help style
}}}
See also `lim` and `box`

==== How do I save a plot or image to a printable file? ====
All of these ''should'' save the current active Kapa window as a file:
{{{
 png outfile.png
 jpeg outfile.jpeg
 ps outfile.ps
}}}
Presently (as of 080814) only the ps command uses the output filename correctly (png saves to ''kapa.png'' regardless of the provided filename) and the `jpeg` command doesn't seem to do anything at the moment.

==== Why does addstar say "Error in config: can't find RADIUS"? ====

This error occurs when addstar can't find a dvo.config file referenced via 'input' in your ~/.ptolemyrc like so:

{{{
 input                   $CONFDIR/$CAMERA/dvo.config
}}}
`CONFDIR` is the config directory (typically defined earlier in ~/.ptolemyrc).

`CAMERA` is the camera name, either also from ~/.ptolemyrc or given on the addstar command line with `-D CAMERA camname`. 

All of these are case-sensitive (except perhaps on a Mac), so you need to give $CONFDIR and $CAMERA in exactly the capitalization as the corresponding directories on your disk, and the directory and file need to exist, of course. Bug #1100 asks for a clearer error message.