Other features of a Ravel

Figure 34 shows a Ravel attached to a Sheet and a Plot, with selections made on two of the Ravel’s 4 axes, so that the output is 2-dimensional: Country by Date, with Date being the x-axis for the Plot and the row entries for the Sheet.

If you rotate the Country axis to the right, Country becomes the X-axis on the Plot and the column entry on the Sheet.

That’s not very informative initially, because most of the entries in the data are blank for early dates. Once you select a quarter with data, there could be up to 43 bars on the horizontal axis (one per country or region), which is also very cumbersome.

To reduce the number of countries displayed, right-click on the Country axis and choose “Pick axis slices”. This brings up the menu shown in Figure 36, where you can pick an individual country by clicking on its name, or select several by control-clicking on the names. You can turn a selection on and off the same way.

Figure 36: Selecting data points on a Ravel Axis

There’s no data at the beginning of the Date axis, but if you now move the selector dot on the Date axis—either by grabbing the selector button with the mouse, or using the up or left arrow

keys to move forward; control-arrow key can also be used, which forces an immediate recalculation of the Plot and Sheet—you can produce a bar chart of the data at that point in time.

Figure 37: Selecting data points on a Ravel Axis

Ravel axes can perform statistical operations as well, using the rollup function as explained earlier, the “Set next aggregation” command.

Figure 38: Calculating averages etc. using Ravel’s axes

This feature is best combined with the Lock, so that you can create a time series—in this case, the average level of household debt by country over time—and use it in later analysis:

Figure 39: Calculating averages etc. using Ravel’s axes