Date post: | 13-Jan-2016 |
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Autoplot Overview Autoplot developed originally for ViRBO Virtual
Observatory, then adopted by VMO, and RBSP instrument and other teams
Autoplot Overview Autoplot developed originally for ViRBO Virtual
Observatory, then adopted by VMO, and RBSP instrument and other teams
Uses existing data resources.
(As opposed to first
downloading the data)
Autoplot URIs
identify data locations.
One URI=one plot
Autoplot Overview Basic idea is it plots the data in a text file or
where ever.
decides render type (e.g. spectrogram or lineplot)
autoranging
few screenshots and demo
I’ll talk about:
• Autoplot’s internal data model, (way of representing the numbers), “QDataSet”
• Autoplot URIs which identify data
• Using Autoplot to get data into Matlab and IDL
• Autoplot’s open source components
Autoplot’s QDataSet Data ModelData model “QDataSet” is in the middle of this. All data is represented in this model.Why not NetCDF / the Common Data Model? Mostly I hadn’t come across it. But it’s very lightweight
and I think it would serve other data systems nicely.QDataSet had been developed for PaPCo, an IDL code. “Ported” to Java and matured in Autoplot.Small Java interface with many implementations.
wrap NetCDFdouble arraysjava.nio.Bufferetc.
QDataSet at the center
QDataSet is at the middle of this, so it’s really: PLUGIN -> "QDataSet" -> DATA CONSUMER
Where plugin is: text files, but also CDF, netCDF, HDF5, OpenDAP, xls,
and jpg, Fits, CEF, ... and … (~20 plugins total)
And data consumer is: Plot graphics, but also: Matlab, IDL, Reformatting,
Data Mining, ???
And fairly extensive set of operators on QDataSet exists already.
Autoplot figure-5-new.PNGESSI Conference 2010
Autoplot URIs
Autoplot defines URIs for locating data, for example:
vap+dat:http://autoplot.org/data/somedata.dat
Autoplot resolves URIs into plottable datasets by identifying the plugin to handle the URI, which resolves the URI into a dataset.
vap+cdf:http://autoplot.org/data/somedata.cdf?BGSM
Autoplot URIs are intended to be stored in bookmarks lists, sent in emails, and stored in SPASE records.
Autoplot data into Matlab
Matlab and IDL have ad-hoc APIs for accessing various forms of data.
Anything you can plot in Autoplot, you can read into IDL and Matlab using the Autoplot URIs.
• Matlab interface is very easy.
• IDL you must use Java connector (but once that’s set up it’s easy)
Matlab Example Script
% Download ~20 MB jar file
javaaddpath('http://autoplot.org/images/AutoplotAll.jar');
apds = org.virbo.idlsupport.APDataSet;
apds.setDataSetURL( ‘http://autoplot.org/data/somedata.dat' )
apds.doGetDataSet;
y= apds.values;
x= apds.values('dep0');
plot( x, y )
Note: CDF files require a C binary and do not work in this mode. (But Nand’s pure-java CDF reader will be incorporated.)
Software ReuseUses open source components
• Things I nothing about: e.g. iText for PDFs, HSSF for spreadsheets, JPEG metadata
• Things for that I know just a little about:
• NetCDF, CDF, OpenDAP for reading data
• Things I know lots about:
• das2 graphics library (Plasma Wave Group, UIowa)
• QDataSet
Software Reuse: use casesAutoplot itself is open source and is being
incorporated into many projects
• Graphics for RBSP mission
• QDataSet incorporated into das2.
• experimental use on ISTP/CDF web server and Ace Science Center.
• Jon Vandegriff hacking out pieces for their RBSP applications at APL.
Software Reuse: das2Autoplot/das2 show how Autoplot provides an application
the RPWS group always wanted.
Autoplot has matured das2 software. Fixed obvious bugs. Very easy to see Plasma Wave Group elements (e.g. simple data model, and its data server) and forces library to become cleaner.
Autoplot has “pushed” das2 to do new things. (e.g. zoom pan, Google maps-like navigation)
Last, provided better technologies into das2, like its QDataSet data model will become heart of das2.
Software Reuse• Apache Math library downloaded and in use within
minutes