xvs: Pull Down Menus

This section contains a brief synopsis of the xvs pull down menus. The menus can be accessed by pressing and holding down the Right mouse button in the active xvs window, generally when the window is in Freeze or Auto mode. (In the other modes, Right clicks are interpreted differently).

Many of the xvs menus are used to invoke functions ("applicators") on the datasets contained in one or more windows. In describing these functions the following notation will be convenient. Denote the contents of a single window as 

Y = [Yn] = [ Y1(X1,t1), Y2(X2,t2), ...  Ynt(Xnt,tnt) ]
where nt is the number of timesteps (datasets) stored in the window, the tn are the discrete times associated with the datasets, and Xn and Yn are vectors of length nxn with components: 
Xn = [ Xn1, Xn2 ... Xnnxn ]
Yn = [ Yn1, Yn2 ... Ynnxn ]

With this nomenclature, we can denote a function (applicator) of one window as: 

F(Y)  or  F1(Y1)
Similarly for functions of two, three, ... n windows we can write: 
F2(Y1,Y2),  F3(Y1,Y2,Y3), ... Fn(Y1,Y2,...,Yn)

The main pull-down menu is composed of the following sub-menus:

IMPORTANT NOTES:

The Stats sub-menu

 Entries in this sub-menu are for de-bugging and diagnostic purposes, and will not be needed in typical xvs use.

The Apply Control sub-menu

 The two entries in this menu enable and disable the apply all feature of xvs.

When this feature is enabled, any function subsequently selected from the Apply xy menu will be applied to all xvs windows, and the transformations will be made in place, i.e. the transformed data will replace the original data, and no windows will be opened.

The Apply xy sub-menu

Entries in this menu generally compute F(Y), using the notation defined above.

The Apply xy hist sub-menu

This is a dynamically-created menu that maintains a history of functions that have been recently invoked via the apply xy menu, so that those functions may be more quickly accessed. The history list is initially empty, so this sub-menu will not appear in the main menu pop-up until a selection has actually been made from the apply xy menu.

The Apply2 xy sub-menu

 Entries in this menu generally compute F2(Y1,Y2)

The Apply3 xy sub-menu

 Entries in this menu generally compute F3(Y1,Y2,Y3)

The only entry in this menu of general utility is

The Apply4 xy sub-menu

 Entries in this menu generally compute F4(Y1,Y2,Y3,Y4)

There are no entries in this menu of general utility.

The Apply6 xy sub-menu

Entries in this menu generally compute F6(Y1,Y2,Y3,Y4,Y5,Y6)

There are no entries in this menu of general utility.

The Applyn xy sub-menu

Entries in this menu generally compute Fn(Y1,Y2,...,Yn)

The Reduce sub-menu

 Selections from this menu perform "x-reductions" of the data in the active window.

Specifically, using the notation defined at the start of this section, the action of the generic reduction function, R, can be defined as 

R(Yn(Xn),tn)
Note that R returns a scalar value for each n = 1, 2, ... nt. Thus, when a reduction is applied to a window with data Y, a new window is created whose data, YR, consists of a single dataset, defined as follows: 
YR = [ Y1R(X1R,0) ]

Y1R = [ R(Y1(X1),t1) ,  R(Y2(X2),t2) ...  R(Ynt(Xnt),tnt) ]
   
X1R = [ t1, t2, ..., tnt ]

Given this notation, the following x-reductions are available---each reduction is followed by a description of the scalar return value of the corresponding reduction function, R.

The Compare sub-menu

 Use the following selections from this menu to compare the data, Y1 and Y2, from two windows.

The Kill window sub-menu

 Use the following selections from this menu to kill (close) windows: