ESRL Global Systems Division

Probabilistic Forecasting Exploratory Development

Legend Overlay and Management

Toggling Cheat Sheet

Within AWIPS, legends have been used quite successfully as a user interface device for manipulating the characteristics of overlays. However, anyone familiar with current D2D ensemble capabilities will realize that if several ensemble fields are loaded, legend management becomes very difficult. So one of the goals of this prototyping was to improve that.

In some ways the new toggling functionality is easier than the collapse functionality because it does not usually change the relative position of the legends. However, it is a very important thing to understand, because the toggle state can directly impact many of the ensemble visualization techniques we will cover later.

Note that for everything we are doing with the toggling, one wants to avoid clicking on the + and - icons (on the left side of the Lengend), but rather click on the items of the Legend.

Step 1: Start D2D.
Step 2: From Volume->Browser..., load Sources Ensemble->SREF-21, Fields Basic->Height, and Planes Pres->500MB (see below, click on image for full resolution). Minimize the VB.

Step 3: Click twice on any item in the Legend (not on the + or - signs at the left side of the Legend) with Mouse Button-3 (MB3), note that all the items in the Legend toggle off (see below, click on image for full resolution) and on.

Step 4: Click twice on any item in the Legend with Mouse Button-2 (MB2), note that the group containing the item toggles off (see below, click on image for full resolution) and on.

Step 5: Click twice on any item with Mouse Button-1 (MB1), note that only that item toggles off (see below, click on image for full resolution) and on.

Step 6: Completely collapse the Legend by clicking MB1 on the - on the left side of the Legend. Repeat the last three steps, note the behavior is now the same for all buttons.
Step 7: With the Legend completely collapsed, click with MB2 on the + on the left side of the Legend. One item from each group is now visible (see below, click on image for full resolution).

Step 8: Click twice on any item (not on the +) with MB3. The items in the Legend toggle off and on.
Step 9: Click twice on any item (not on the +) with MB1. The item toggles off and on. Collapse the Legend by clicking on the + with MB1.

The key point here is that when collapsed, all elements of the collapse toggle together, but otherwise MB1 does individual items, MB2 does groups of items, and MB3 does all items in the Legend.

Step 10: With the Legend completely collapsed, from the VB, load Sources Sources Ensemble->SREF-21, Fields Basic->Height, and Planes Pres->700MB (see below, click on image for full resolution). Minimize the VB.

Step 11: On the KeyBoard, try hitting 1 and 2 from the numeric KeyPad, note the response. Numbers 1 and 2 toggle off and on the collapsed 500MB and 700MB items in the Legend, respectively.
Step 12: Completely expand the items in the Legend, by clicking with MB1 on the +. Now the 500MB and 700MB items are expanded (see below, click on image for full resolution).

Step 13: Again try hitting the numbers 1 and 2 (the numbers depend on how many items are overlayed in the Legend, in this case we have 2 overlays in the Legend, so only numbers 1 and 2 correspond) on the numberic KeyPad, note the response. Numbers 1 and 2 now toggle off and on the 500MB (see below, click on image for full resolution) and 700MB (see below, click on image for full resolution) overlays, respectively, in the Legend.
  

The point here is that the numeric KeyPad toggles by load order, not overlay order.

Step 14: Clear the screen.
Step 15: Exit D2D.