15. Inspecting data

Any item appearing in the Variables or Outline views with a green dot to its left can be opened with one of HIPE viewers. See Section 17.15 for how to display the contents of a variable with the default tool or with another available tool.

An example is shown for a SimpleImage. A right-click on a variable of this type in the Variables view shows there are three viewers (see Figure 19). The Product Viewer shows associated metadata and array values (see following section); the Wcs explorer shows WCS settings; the Standard Image Viewer displays the image.

Available viewers are shown with a right-click.

Figure 19. Available viewers are shown with a right-click.

See the Data Analysis Guide for information on viewers in HIPE, in particular the sections on data display of the Data Analysis Guide, that is image, product metadata and spectrum viewing. The next sections introduce the generic data product viewer, the observation viewer and the dataset viewer.

15.1. Inspecting products

All Herschel data come packaged as products. The Product Viewer, shown in Figure 20, gives you a summary of the product and lists the metadata and data it contains.

The Product Viewer.

Figure 20. The Product Viewer.

The Data section is divided into two areas. The left area shows a hierarchy of the product contents. Click on an item to open it in the right area, in its default viewer. You can maximise the viewer by clicking the icon. Above the viewer there is a reference you can use in the Console view to extract the data and assign it to a variable. Click the icon to copy the reference to the clipboard. In the case shown in Figure 20, you would assign the data to a variable with this command:

HIPE> myImage = myProduct["image"]

Right click on an item in the left area to open a menu with the following options:

  • Open: opens the item in its default viewer, in a new tab inside the Editor view.

  • Open With: allows you to choose the viewer for opening the item.

  • Send to: sends the item to a FITS file, a text file or to a Virtual Observatory-enabled application.

  • Create Variable: creates a variable referring to the item, much like you can do manually by copying and pasting the item reference to the Console view.

[Tip] Tip

Another way to create a variable is to drag the item to the Variables view.

15.2. Inspecting observations

An observation is packaged as an observation context , a kind of product containing other products, so it is not surprising that the Observation Viewer , shown in Figure 21 , is very similar to the Product Viewer .

The Observation Viewer.

Figure 21. The Observation Viewer.

All the features of the Product Viewer also work in the Observation Viewer . In addition, note the following:

  • The Summary section may include a thumbnail image. Click on the thumbnail to enlarge it. Click again to go back to the Observation Viewer . The thumbnail does not open in the HIPE image viewer.

  • Red entries in the left area of the Data section have not been loaded into memory. HIPE does not load an entire observation at once to save time and memory space. Click on a red entry to load it into memory and display it.

15.3. Inspecting datasets

HIPE data inside products come in tabular form and are packaged in datasets . Datasets are automatically shown within the Product Viewer and the Observation Viewer . You can also open a dataset separately by right clicking on its name and choosing Open WithDataset Viewer.

The Dataset Viewer shows the metadata associated with a dataset and the tabular data itself.

The Dataset Viewer. Note the pop-up option to display numbers in hexadecimal.

Figure 22. The Dataset Viewer. Note the pop-up option to display numbers in hexadecimal.

Changing the column ordering. Click a column header to sort the table rows according to the values in that column. Click a second time to reverse the sorting order. Click a third time to restore the default order.

Changing the format of integer numbers. To display integer numbers (types int and long) in hexadecimal, right click on a cell with an integer number and choose Display numbers in hexadecimal. To return to the decimal display, right click on a cell with a hexadecimal value and choose Display numbers in decimal. These settings apply to all the integer values in a table.

Changing the format of dates. To display dates (such as the startDate and endDate fields in the metadata) in International Atomic Time (TAI), right click on a cell with a date value and choose Display dates in TAI. To return to the display in Coordinated Universal Time (UTC), right click on a cell with a date value and choose Display dates in UTC. These settings apply to all the date values in a table. For more information on TAI and UTC, see the Scripting Guide: Section 9.1, “Time Definitions”.

Editing values. To edit values in a dataset, right click on any cell and choose Allow editing. You can then double click on any cell to edit its contents. All the changes you make are echoed to the Console view. To stop editing values, right click on any cell and choose Stop editing.

For more information on datasets, see the following sections of the Scripting Guide: