Catalog Search Tool: Tables

Tables: Interacting with Tables

Search results from the Catalog Search Tool (or the tool called Atlas) return results in an interactive table. This section describes features of this interactive table.

Contents:
+Header: the top of the table
+Columns
+Filters -- Filtering the table

Header: the top of the table

At the top of the table, there may be several symbols, for example:

which we now describe.

The first 100 rows of the search results are displayed in the table. In the example, there are 589 sources that were retrieved as part of the search. The black arrows plus the page number allow you to navigate among these 'pages' of 100 sources each. Note that the entire set of results (not just the 100 rows you are currently viewing) can be sorted alphabetically by clicking on any column's name.

Going from left to right along the top of the catalog tab, the next icon represents a filter: Filters are complex and powerful enough that they are covered in a separate section below.

The next icon is -- clicking on this changes the table display into a text display. The icon then changes to -- click this again to return to the default table view.

The next icon is which is "Save" -- this is how you may save the whole catalog to your own local disk. It will save it as an IPAC table file, which is basically ASCII text with headers explaining the type of data in each column, separated by vertical bars. By default, the file is called "GatorQuery.tbl". Note that it will save your whole catalog if you save without filtering. If you filter, the header of the file will still say that all the rows are included, but only the filtered-down rows are saved.

The next to last option on the top of the catalog tab is this: . Clicking on this icon brings up options for the table, e.g., how many rows are displayed per page, and which columns are shown. By default, all columns are shown. The default page size is 100 rows. Note that expanding the page size to numbers much greater than 100 may result in a substantial performance degradation (e.g., your browser will appear to freeze or not appear to be doing anything while it manages and renders the large table).

Finally, this is the last option on the top of the catalog tab: . Clicking on this expands the catalog window pane to take up the entire browser window. To return to the prior view, click on "Close" in the upper left.

Columns

Depending on what you did to display a table, the columns that are shown may be in easily-human-readable form, or may reflect column names used within the individual catalog. Please consult the detailed documentation associated with your specific archive if the headers are not clear to you.

There may be flexibility to display or hide columns, as described in the headers section above.

Clicking on the column names sorts the table by that column; clicking once sorts in ascending order, clicking a second time sorts in descending order, and clicking a third time returns the table to the original order. Small arrows appear next to the column names to remind you if the column is sorted in ascending or descending order.

Filters -- Filtering the table

Filters are a very powerful way of exploring the table full of search results. Click on this icon

in order to start the process of adding filters. A text entry box appears above each of the current catalog columns, with a small version of the filter icon corresponding to that row on the far left. You can type operators and values in these boxes -- hit return after typing or click in another box to implement the filter. For fields with a limited set of choices, instead of a text entry box, a filter icon will appear; click on it to select from the available choices.

Example 1: Atlas search results are a list of images meeting your search criteria. They may not all be science images -- some may be errors or coverage maps. To just view the science images, filter down to just leave the science images. Click on the filter icon, and type "science" in the box above the corresponding columns. The table is filtered down to leave just the science images.

Example 2: From a catalog, show only those sources with declination above a certain value (say, 31 degrees), type "> 31" in the box above the "dec" column. Or, if you have retrieved a WISE catalog and would like to only view the objects with a W1 (3.4 micron) profile-fitted magnitude less than 6 magnitudes, above the 'w1mpro' column, type "< 6" in the form.

After you impose a filter, then the number of rows in the catalog is restricted according to the rules you have specified, and the "filters" icon on the top right of the catalog pane has changed to remind you that there has been a filter applied, in this case just one filter: . To clear the filters, click on the cancel filters icon (which also appears after you impose filters): .

Note that the filters are logically "AND"ed together -- it will impose this AND that AND this other restriction. You can relatively easily restrict things such that no data are left; if that is the case, you will get "There are no data to display." You can then cancel all the filters at once via the cancel filters icon (), or remove them individually by hand by editing the filter boxes at the top of each column, just as you did to impose the filters.

The available logical operators are :

= which means 'equal to' (exactly!), e.g., the parameter on which I am querying (the column headers as shown) is exactly equal to this value I am specifying.
> which means 'greater than'
< which mean 'less than'
!= which means 'not equal to' (exactly!)
>= which means 'greater than or equal to'
<= which means 'less than or equal to'
IN which means 'included within this list', e.g., the parameter on which you are querying (such as "Bandpass") is included within the list you are specifying (if the column filter is free-form text, type "value1,value2" and it will give you rows that have value1 or value2).
LIKE which means 'resembles the text that is entered', e.g., the text resembles the text that you type in the box.