VIM Tools
Here is a short explanation of the action of each of the menu items available in VIM. Not all of these will be available all the time, for example if Sky Positions are already loaded, then the Load Sky Positions menu is no longer available. If the workbench is not write-enabled, then there will be no menu items that cause writing in the workbench.
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Load Sky Positions
The Vim application finds data about a set of sky positions (also called sources), each characterised by a position (RA and Dec in ICRS), and by an identifier. Once the set of positions is ingested to form the source table, this menu is no longer visible.
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from Text
VIM has its own very simple text-import facilities: a list of positions with each line showing RA, Dec, ID, for example two sources can be shown as:
123.45, 67.89, RX_567
234.56, 78.90, HX_455
A much more sophisticated text import is available through the NVO Table Import Wizard, at
http://us-vo.org/tablewizard, which can convert delimited or fixed-width
tables to VOTable, which can be ingested as a "local VOTable" as below.
The tool can be called from python like this:
textPositions.run(bench, textPositionsString)
where textPositionsString is a string containing text positions in the format RA, Dec, ID as above.
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from link to VOTable
A source VOTable is one that has identified columns for RA, Dec, and identifier. This is how to fetch a source VOTable from a URL link that points to the table.
The tool can be called from python like this:
sourcesURL.run(bench, sourcesURLString)
where sourcesURLString is a string containing a URL that points to a source VOTable.
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from local VOTable
A source VOTable is one that has identified columns for RA, Dec, and identifier. These can be obtained from all of the VO-enabled data centers, and downloaded. Then use this tool to upload the sky positions into Vim.
The tool can be called from python like this:
sources.run(bench, sourceVOTableString)
where sourceVOTableString is a string containing a source VOTable.
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Fetch Data
The tools in this section can be used to fetch data from the internet, that will be formed as other tables alongside the sky positions table; these 'matched tables' have a foreign key from the identifiers of the sources table, and are displayed alongside the source table.
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VO Proximity Search
This tool matches the source table against a published catalog, taken from the current cache of catalogs. Choose the catalog and a radius, in arcseconds, and a table is built of all sources from the catalog whose distance from one of the uploaded sources is less than the radius. This tool should be used for matching all catalogs except SDSS, which has its own boutique way of doing proximity searchs (see below).
The tool can be called from python like this:
proxsearch.run(bench, survey, sr, tablename, verb, maxthreads)
where survey is the name of the catalog to match against, for example "FIRST" or "NED (sources)"; sr is the radius of the proximity search in degrees, tablename is the name to use for the results; verb is the verbosity of the resulting table, from '1' (minimum) to '3' (all data columns returned), with '1' as ythe default; and maxthreads is the number of threads to use, which defaults to 10 if this argument is omitted.
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Skyview Cutouts
This tool makes cutout images from the Skyview virtual observatory, which can build cutout images from any of 90 or so surveys. You can choose multiple surveys from the list (option click or control click).
The tool can be called from python like this:
skyview.run(bench, isize, surveylist, tablename)
where isize is the size in pixels of the resulting cutout; surveylist is a python list of
Skyview image surveys, for example ["DSS2B", "SDSSG"],; and tablename is the name of the table
for the results.
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Get Spectra
This tool fetches spectrum data from the NRAO/JHU spectrum services, finding all proximate objects to each sky position that have spectra from one of several collections, including the SDSS DR5.
The tool can be called from python like this:
spectra.run(bench, isize, collection, tablename)
where isize is the size in pixels of the resulting spectrum image; collection
is a choice of:
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"ivo://jhu/sdss/dr5": Sloan Digital Sky Survey Spectral catalog
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"ivo://naic/Arecibo_OH_IR_stars": Arecibo Maser Catalog
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"ivo://jhu/2df": 2DF survey
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SDSS Proximity Search
This is a special version of proximity search for the Sloan Digital Sky Survey. It is also much faster for large numbers of sources.
The tool can be called from python like this:
sdsssearch.run(bench, tablename, sr)
where tablename is the name of the table to be made, and sr is the
proximity search radius in degrees.
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Catalogs
The principle of Vim is that a user-supplied source list is crossmatched with published catalogs. Vim has a cache of 14 such catalogs, and thousands more are available, that can be found by keyword search at the NVO registry and added to the cache. Catalogs can also be found through spatial matching: those which contain many of the users sources.
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Find catalog Services
This tool passes control to the NVO registry. Put in relevant search terms, then look at the returned resources and select the ones you want. At the top right, where it says Next, Send Results to, select VIM and press Send. The new catalogs will now be in the cache.
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Find Correlated Catalogs
This tool connects to the NVO Inventory service to find catalogs that are well correlated spatially to the given source list. Again, the result is that the cache contains more catalogs.
The tool can be called from python like this:
inventory.run(bench, tablename, sr)
where tablename is the name of the table to be created, and radius is the radius in degrees to be
used by the inventory service.
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Add Catalog by Ivorn
This tool allows the input of an Ivorn (a call number system from the virtual observatory
movement), and addition of the corresponding catalog to the Catalog Cache.
The tool can be called from python like this:
addIvorn.run(bench, ivorn)
where ivorn is the IVOA resource identifier of the resource, for example ivo://nasa.heasarc/baxgalclus is the identifier
for the service at HEASARC that exposes the BAX X-Ray Galaxy Clusters and Groups Catalog. These IVORNs can
be obtained from the NVO registry service.
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Add Catalog Table
This allows upload of a VOTable that contains catalog specifications. You can get such a table from the NVO Registry if you do 'save results as VOTable'.
The tool can be called from python like this:
findResources.run(bench, resourceTableStream)
where resourceTableStream is the name of a stream containing a resource-VOTable -- a table of catalog resources.
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View Catalog Cache
This tool shows the list of all catalogs currently available for proximity searches, with some information about the provenance of each.
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Mine Data
These tools make changes to the tables that allow selections and computations.
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Merge with Positions
This tool allows data from match tables to be added to the source table, it is a crossmatch. Each position from the source table can be matched to either (a) the nearest match to that position from the match table, or (b) to all of the positions (outer join). After the merge, use the Table Columns / sources tool to select which of the merged columns to display.
The tool can be called from python like this:
join.run(bench, tablename, match)
where tablename is the name of the table to be joined to the source table, and match can either be "all" to build an outer join, or "best" to mean take only the nearest catalog source to the original source.
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Select Rows
This allows records to be removed from a table based on a criterion. For example, we may wish to eliminate faint objects from a table, or those which have a null value in some column. Examples of expressions are Jmag<18 && Nmag<18 or ! NULL_Jmag to keep only those whose Jmag value is not null.
The tool can be called from python like this:
selectrows.run(bench, tablename, criterion)
where tablename is the name of the table where rows will be removed, and criterion is the string expression
defining which rows are to be kept: when the expression is TRUE, the row is KEPT.
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Compute New Column
This tool allows the creation of a new column of a table, that is computed from the values of other columns in the same table. An example might be a J-N color computed from Jmag and Nmag columns as Jmag-Nmag. If you want to compute a new column from different tables, they must be merged first (see above).
The tool can be called from python like this:
addcol.run(bench, tablename, colname, expression)
where tablename is the name of the table to have a new column, colname is the name opf the new column,
and expression is the arithmetic expression to be evaluated.
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Table Columns / <table>
Each submenu here displays the data dictionary (table metadata) for one of the tables in the workbench. You can see the name, ID, ucd, units, and datatype for each of the table columns, and a check box toggles display of that column in the table display.
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Utility
Various utility functions.
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View All Files
This tool shows links to all the files in the workbench. In particular, the data tables (with the suffix .votable) can be downloaded or viewed, and the detail.txt file shows diagnostic history from runing the previous tools.
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Sort
Sorts the source table by any of its columns. To sort on data in the match tables, first merge with the source table. Note that the table records that are shown in the display can be sorted simply by clicking the tops of the columns.
The tool can be called from python like this:
sort.run(bench, colname, down)
where colname is the name of the column to be used for the sorting, and down is either 0 or 1 for ascending or descending sort respectively.
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Pages
Allows viewing of a subset of the sources. If the page size is 100 and looking at page 3, we see rows 201 to 300.
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Sex degrees
Choice of coordinate representation, decimal degrees or sexagesimal, or both (the default).
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Make CSV
This tool makes a CSV (comma-separated values) file from the source VOTable. Then use View All Files to see and download the result.
The tool can be called from python like this:
download.run(bench, "CSV")
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Make KML
This tool makes a KML file from the source VOTable, suitable for use in Google Sky.
Then use View All Files to see and download the result.
The tool can be called from python like this:
downloadKML.run(bench)
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Delete Table
Deletes a table from the workbench.
The tool can be called from python like this:
deletetable.run(bench, tablename)
where tablename is the tabel to be deleted.
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Help
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