topcat & stilts

TOPCAT & STILTS

Primer Curso Práctico de la red Temática SVO

Granada, 27-28 de octubre de 2009

Francisco Jiménez Esteban Spanish Virtual Observatory

LAEX-CAB (INTA-CSIC)

TOPCAT

• Interactive graphical viewer and editor for tabular data.

• It can examine, analyse, combine, edit and write out tables.

• It understands a number of different astronomically important formats.

• A million rows by a hundred columns.

Francisco Jiménez Esteban – SVO – [email protected] Granada 27-28 de octubre de 2009

TOPCAT: Control Window


- The right hand panel describes the characteristics of the current table.

- The buttons along the top allow launching of various other windows.

TOPCAT: Load Windows


Load Data:

- You can load your local tables.

TOPCAT: Load Windows


Cone Search:

- Service available on the web.

- The list is obtained from a VO registry.

TOPCAT: Table Windows


Data:

- Scroll around.

- Sort rows.

- Define subsets.



Columns:

- Information about each column.

- Columns can be hidden/revealed, and new ones added.



Subsets:

- See all the row subsets defined, and to define more.

- Can be defined using algebraic expression, or graphically.



Statistics:

- Calculate statistics for all or a selection of rows.

TOPCAT: Plot Windows


- Set axis labels and ranges

- Different colors or symbols for different sets of data.

- Error bars

- Configurable plot markers

- Zoom in or out.

- Select a Subset.

1D histograms:

- Set bin width and offset



2D:

- Plot pairs of columns.



3D:

- Plots on Cartesian axes.

- Rotate the axes by dragging the mouse.



Spherical Polar:

- Plots 3D plots on spherical polar axes.

- Plot points only on the surface of the sphere or on the interior.

- Rotate the axes by dragging the mouse.



Stacked Line:

- Plots one or more X-Y line plots using the same X axis but different Y axes.

- This can be particularly useful for visualizing time-series data.



Density Maps:

- The intensity of color at each pixel reflects the number of points that fall within its bounds.

- Pixel size can be changed, cut levels can be altered.

- This is very useful for analysis and visualization of extremely crowded plots.

TOPCAT: Match Windows


Concatenate:

- Concatenate the rows of existing tables to create new ones.



1 Table:

- Mark groups of rows.

- Eliminate All grouped.

- Eliminate All but First.

- New tables with groups.



2 Tables:

- Specify a match operation which will join two tables.

- A wide range of multivariate matches is possible.

TOPCAT: Functions Windows


Available Functions:

- Displays the details of the functions which can be used to define new columns and subsets.

STILTS


STILTS is a set of command-line tools for processing tabular data. Its facilities:

- Cross-matching- Format conversion and validation- Column calculation and rearrangement- Row selection- Sorting- Plotting- Statistical calculations- Metadata display

STILTS


- Accept streamed data so the size of tables which can be processed is not limited by available memory.

- In general, the form of a command is

java –jar /path/stilts.jar <stilts-flags> <task-name> <task-args>

topcat & stilts

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