You may have noticed when you right-click on an axis selector in Spotfire, one of the options available is 'Column from Marked'' and this tip will help you understand how it can be used. This feature allows you to configure a visualization, normally a table, that controls the column used as an axis in a second visualization. An added bonus is this works in the Web Player, which provides some additional capabilities for Web Player users to define what goes on an axis of a particular visualization.
Details Step-by-StepThe dialog box below is displayed when you select the Column from Marked option. To get to it, right-click on any axis indicator.
You need to identify a table and column combination which in its turn contains column names for the table which is driving the visualization ' this can sound confusing without an example. So consider the Department List table shown below. It refers to the shopping deparments in a large department-style store. To simplify this example, it just has one column called Department and can take the values Electronics, Furniture, Garden, Groceries, Clothing or Toys.
With the Colum from Marked dialog box configured as shown (having right-clicked on the Y-axis of the Scatter Plot to set the Column from Marked properties) the Y-axis column is now chosen by marking a row in the Department List data table. At the moment, Clothing is shown. Highlighting Furniture in the table changes the Y-axis accordingly:-
Notice that the small square image on the Y-axis selector, highlighted in red, indicates that Column from Marked is active.
Why Use It?Two of the best uses for this feature include (1) the ability to easily handle different 'shapes' of data, or (2), to give Web Player users a way to modify the axes of a visualization.
(1) Although this example has used a simplified table with a list of all departments, this need not be the case. The department list table could have lots of other data, and it need not even be contained in a separate table. However, this use of a second table to configure a visualization means that you can handle different 'shapes' of data, in similar manner to a Pivot. In this case, the department list table could be considered 'tall-skinny' and the actual sales data driving the scatter plot is 'short-wide' and both can co-exist to be used when appropriate. In this use, the feature is an alternative to pivoting your data, which of course can also be done in Spotfire very easily.
(2) You may already know that users of the Spotfire Web Player and Spotfire Enterprise Player cannot change the axes of visualizations. The Column from Marked feature provides a way to allow such users to change axes, although in a limited way. This gives them an alternative to changing filter settings, and in this case means that there are really six scatter plots, one for each department, in one! This can also save space on-screen in files intended for Spofire Professional users.
There are other examples of this feature in the Spotfire Data Relationships tools. The output of these tools is a data table plus a visualization which automatically has Column from Marked enabled.
Hopefully these tips will get your imagination working, but don't forget that the visualization which provides the column names via a marking does not have to be a table, it can be any Spotfire visualization. Also, there are more advanced expressions which can be used: these are explained in the online help.
To see one working in a live demo, visit this month's Analytics in Action file where we analyze food items from popular fast food restaurants.
