Tutorial: Cinema Viewers

This tutorial will help the user explore the CinemaScience ecosystem. It will discuss how to view Cinema databases (CDBs) with the standard Cinema Viewers.

The CinemaScience GitHub page and the CinemaScience website are useful sources for more information and ideas.

Viewing Cinema Databases

Note: Cinema databases should be viewed in Firefox to avoid cross origin security errors.

The basic Cinema viewers operate on the Cinema Spec D specification. In each case, CDBs are assumed to reside in a data/ directory. Each CDB consists of a default data.csv file with columns of data abstracts following Spec D requirements (see CinemaScience Specifications), and any subdirectories needed for the data abstracts such as images, vti files, or additional csv files. The database viewers are described below.


CinemaCompare is designed to access the images within one or more CDBs, providing sliders spanning the values in the databases in order to select a specific image or set of comparison images. CinemaCompare can be downloaded from the cinema_compare GitHub page. This download will result in several directories and an index.html:

$ ls -l

The data/ directory includes a test CDB, sphere.cdb with its required data.csv, and an image/ subdirectory with the images arranged into subfolders by the phi variable.


In the default sphere example, there are 20 phi values and 1 theta value saved in the data.csv:


The index.html file defines the set of databases to display in the dataSets variable. Edit index.html and modify dataSets to point to one or more databases.

Viewing the single sphere requires a single database entry in dataSets:

// START: Array of databases to view
    var dataSets = [ "data/sphere.cdb" ];
 // END : Array of databases to view

Opening index.html in Firefox:

$ open index.html -a Firefox

will bring up the CinemaCompare viewer. The sliders allow you to change the image size and the orientation.

MPAS image

Edit the dataSets variable in index.html file to compare multiple databases. Multiple databases are not required to have matching variable ranges. The viewer will select the maximum range and display a default null image if one of the databases does not have that corresponding data row.

The sliders control all three databases in common:

// START: Array of databases to view
    var dataSets = [ "data/wavelet1.cdb", "data/wavelet2.cdb", "data/wavelet3.cdb" ];
 // END : Array of databases to view

Common Error Note: Mistyping a database name or forgetting the data/ directory part will result in a TypeError. Open the console window if nothing appears and check for the error. If so, check the dataSets variable in the index.html file for errors.

TypeError: results is undefined

Note that videos showing CinemaCompare for single and multiple databases can be seen on the CinemaScience Examples website.


CinemaExplorer is a parallel coordinates approach to selecting and viewing data in a Cinema database. CinemaExplorer can be downloaded from the cinema_explorer GitHub page. This download will result in several directories and an cinema_explorer.html:

$ ls -l

The default data/ directory contains subdirectories with example CDBs to illustrate the range of functionality of CinemaExplorer. Again, each CDB consists of a data.csv file and any needed subdirectories for its data artifacts. An image/ directory is common and the file_types.cdb includes a wavelet/ subdirectory with vti files that can be viewed with CinemaExplorer.

sphere... code-block::

The set of databases for CinemaExplorer is defined in a databases.json file found in:


databases.json follows JSON syntax rules. Each database entry minimally requires a name and a directory.

                 "name" : "sphere",
                  "directory" : "data/sphere.cdb"
     "name" : "Many File Types",
     "directory" : "data/file_types.cdb"

Opening the cinema_explorer/cinema_explorer.html file in Firefox

$ open cinema_explorer.html -a Firefox

will bring up CinemaExplorer in a browser window. The default view has a parallel coordinates display of the data.csv columns. Each column corresponds to an axis.


By default, the first database listed in databases.json will load initially. All databases in databases.json will appear in a dropdown menu under Select Database: in the CinemaExplorer browser window. After selecting a CDB, click on the Load button to switch to that CDB.

_images/SelectDatabaseDropdown.png _images/SelectDatabaseLoadButton.png

Under the parallel coordinates, the default tab is the Image Spread component. The image spread includes controls to change the image size, the results per page, and the sort variable and order. Let’s switch to the Big Bogus 2 database. It has several additional axes of (bogus) variables and more images than can fit in a single page. Note that CinemaExplorer switches between Canvas and SVG versions to accommodate the size of the database.


The page navigation widget at the bottom of the Image Spread allows the user to cycle through all the images.


The second tab, on the right, is a ScatterPlot component. Each axis variable can be chosen from a dropdown menu of all axes so each variable can be plotted against any other variable.


The parallel component view provides a standard set of flexible actions to select and highlight data. Hovering over a specific data point or image in the CDB highlights its trace in the parallel coordinates plot and brings up a card with the detailed information from that database row:


Another useful feature is a modal view. Clicking on a single image will bring up that image for closer inspection. Clicking anywhere in the main screen will dismiss the modal image. Here we select the image highlighted above.


A subset of the data can be selected via the parallel component axes. Left-mouse-click-hold-and-drag to select a range on an axis. A subset of six of the original 20 images is now visible:


That range can be shifted by hovering over the selected range then left-mouse-click and hold-and-drag. Or it can be modified by selecting one edge and dragging just that edge to increase or decrease the selection range. Here, the range has been decreased to only select four of the database rows/images:


The selection can be cancelled by clicking on the previously selected axis. Selection on the axes is a particularly useful feature to, e.g., identify and explore outliers in the data.

Optional Control Fields for databases.json

There are three optional control fields that can be implemented within the database.json file to control the data viewed on the parallel coordinates axes.

  • filter is a JSON regular expression which removes the specified axes (columns) whose header matches the regex. Note that adding filter will override the default filtering for any FILE* columns so those will need to be explicitly removed. This example with the Bogus 1 data removes the Float_6 axis and all axes that begin with FILE:
  "name" : "Bogus 1",
  "directory" : "data/bogus/bogus_1.cdb",
  "filter" : "(^Float_6)|(^FILE)"
  • query queries the database and only displays those rows that match the criterion for the columns queried. This example with the Bogus 1 data displays only those rows where Float_6 is within the range [20-70] and Interger_2 is within the range [40, 60]:
  "name" : "Bogus 1",
  "directory" : "data/bogus/bogus_1.cdb",
  "query": {
    "Float_6" : [20, 70],
    "Integer_2": [40, 60]
  • selection applies an axis selection when the database is loaded but loads all database rows. This example with the Bogus 1 data brings up the database with the selection on Integer_3 already in place:
  "name" : "Bogus 1",
  "directory" : "data/bogus/bogus_1.cdb",
  "selection": {
                      "Integer_3": [20, 50]


CinemaScope is a prototype cross platform application viewer to interactively explore images in a Cinema database. CinemaScope can be found on the cinema_scope GitHub page. Under the readme, click on buildpassing to bring up the list of builds. Currently, builds are available for Linux, Windows, MacOS, and MacOS/Xcode:


Download the relevant build and install. Test databases are available in https://github.com/cinemascience/cinema_scope/tree/master/docs/data/test_cylinder.cdb.zip. CinemaScope looks for a settings file in:


This INI-style settings file includes a pointer to the data directory. Edit settings.ini to point to the location of the data directory:


Open CinemaScope after it has installed. Click on File -> Open to open the data directory and select the data set by highlighting test_cylinder.cdb (do not click into the directory) and clicking Open.

_images/cs_FileOpen.png _images/cs_DataDirectory.png

This will load the test_cylinder CDB.


The mouse wheel can be used to increase/decrease image size. Each parameter in the CDB data.csv will correspond to a slider. The sliders can be used to control the parameter values. In this case, changing phi and theta rotate the cylinder.


Mouse drag can also be used to scroll through the images. Up/down is linked by default to theta while left/right is linked to phi. The linked parameters can be modified using the Map Parameters Dialog. Click Edit –> Edit Parameters to open the dialog and select the parameters from each dropdown menu. For CDBs with multiple artifacts, the Artifact dropdown menu will allow you to access each set of images.


An optional csettings.json file, which must be located in the *.cdb directory, can be used to limit the number of parameters actually linked to a slider or reorder a list of parameter columns. The colorder (“column order”) variable contains the list of actively linked parameters.


    "colorder" : ["phi", "theta", "xValue", "yValue", "zValue", "FILE", "FILE_2"]

Other Cinema viewers

Additionally, there are other application-specific Cinema viewers that provide useful examples and inspiration for Cinema users and developers. We invite you to explore the CinemaScience GitHub for an up-to-date listing of example viewers. Cinema Viewers, in particular CinemaScope, are in active development. We invite users to join the Cinema community and contribute to the Cinema project.