Download presentation
Presentation is loading. Please wait.
Published bySamantha Saunders Modified over 11 years ago
1
STILTS – Command-line tools for table/VOTable manipulation TOPCAT VO features – VO features in the GUI tabular data exploration tool SPLAT-VO – SSAP functionality in GUI spectral analysis tool Starlink VO Applications Software http://www.starlink.ac.uk/
2
STILTS Command-line tools for table manipulation VOTable structure-sensitive tools – votcopy: DATA encoding conversion – votlint: VOTable document validation Generic table tools: – tcopy: format conversion – tpipe: table pipeline processing Current release is beta STIL Tool Set http://www.starlink.ac.uk/stilts/
3
tcopy Converts tables between formats Streaming operation where possible Extensible to new formats VOTable FITS SQL query ASCII CSV... VOTable FITS SQL table ASCII HTML LaTeX Mirage... tcopy
4
tcopy usage scenarios The VO is a heterogeneous environment Convert from legacy formats to FITS/VOTable Adapt VOTable data to formats suitable for legacy tools Populate SQL databases from FITS files –... or vice versa Provide choice of output format for table query output – put tcopy as a layer between standard output and what gets delivered to the user – easy to write an HTML form providing output format options – or a web service parameter naming chosen format Interoperability!
5
tpipe Multi-purpose scriptable table pipeline Uses powerful extensible expression language VOTable FITS ASCII CSV... file stream SQL query select rows new column delete column rearrange cols sort rows sample rows head/tail VOTable FITS ASCII CSV... file stream new SQL table calculate statistics show metadata display in TOPCAT input output process
6
tpipe expression language Algebraic expressions in terms of existing columns – Used for row selection, defining new synthetic columns – Refer to existing columns by column name or index – Normal arithmetic/relational operators plus useful functions trigonometry, string handling, coordinate conversion, conditionals,... – Null value handling supported Compiled to Java bytecode at runtime (uses JEL) – Fast execution – Full power of Java language Extensible by supplying own classes at runtime
7
tpipe examples Display first few rows of table tpipe survey1.xml -head 5 Select rows on algebraic expression tpipe cat.fits -select 'BMAG < 21.2 && startsWith(NAME,cyg)' -write catsub.fits Add new calculated columns tpipe -ifmt csv data.csv -addcol MAG_MEAN 0.5 * (IMAG + VMAG) -addcol IV_COLOUR VMAG - IMAG Convert columns from sexagesimal to degrees tpipe -ifmt csv acat.csv -addcol RA 'radiansToDegrees(hmsToRadians($1,$2,$3))' -addcol DEC 'radiansToDegrees(dmsToRadians($4,$5,$6))' -delcols '$1,$2,$3,$4,$5,$6' Calculate and display statistics on sample of large table tpipe USNO-B.FITS -every 1000000 -stats Display the thousand highest redshifts in TOPCAT tpipe 2QZ.fits.gz -keepcols NAME RA DEC Z1 -sort Z1 -tail 1000 -topcat
8
tmatch... maybe one day
9
TOPCAT View/analyse/edit/write tabular data – Manipulate table data and metadata – Plot, match, sort, calculate, select,... – Powerful and extensible expression language – Multi-format, including VOTable (all encodings) & SQL – Large tables (10^6 rows x 10^2 columns) http://www.starlink.ac.uk/topcat/ Tool for OPerations on Catalogues And Tables
10
TOPCAT VO features Load/Save dialogues – Filestore browser – Cone search – SIAP query – Registry query Activation actions – Display images/spectra corresponding to table rows
11
Filestore Browser Looks like standard file chooser Remote filespaces are available in the same way as local filesystem Log in/out to view remote filespaces Both load and save are available Pluggable framework for filespace implementations – Currently MySpace and SRB supported – Not hard to add new ones Available as separate library component for use in other applications
12
Cone Search Get cone search services from registry Perform a query on one of the services returned Open results as a table SIAP and Registry queries work in a similar way
13
Activation actions Can configure some action when table row is activated Activation performed by: – clicking on row in table display – clicking on point in plot Actions include: – display cutout image from service (SoG) – display spectrum from service (SPLAT) –... or anything you like
14
TOPCAT as service client Query registry for SIAP/Cone search services Perform a query on one of the services returned Plot/view results and select a point/row Retrieve resulting data file and display image/spectrum...but it's a bit clunky
15
Starlink SPLAT for the VO
16
SPLAT features Not just a VO client, also an analysis tool with extensive graphics features, printing, zooming, scrolling etc. Source code available under GPL. Available as a desktop or webstart application (Linux, Windows, Mac OS X and Solaris). http://www.starlink.ac.uk/splat-vo
17
New SSAP Browser Various interactive features: object name lookup, RA and Dec in natural units ( hh/ddd:mm:ss.s ). Simple double click to load a spectrum.
18
Double click download
19
Starlink AST All coordinate and units transforms provided by AST. Spectral coordinates cover FITS-WCS paper III: Wavelength, Frequency, Energy and Velocity Flux units, based only on interpretation of standard FITS-WCS paper I descriptions: Jy, W/m^2/Hz, W/m^2/Angstrom, W/cm^2/um, erg/cm^2/s/Hz, erg/cm^2/s/Angstrom
20
Composite plot of VO data
21
3C273 all frequencies
22
Summary STILTS – tcopy - table format conversion – tpipe - table pipeline processor TOPCAT VO features – local/remote filestore browser – passable SIAP/Cone search service client SPLAT-VO – Spectral analysis program, SSAP client, sophisticated coordinate handling Other items not mentioned here The future is uncertain...
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.