Volume 2 Chapter 4 Display Menus DIALBOX

Function

This feature is located, for each hit, in the 3D and 2D/3D displays.

It allows the user to edit the 3D crystal diagram in terms of three operations:

rotation
translation
scaling

Remarks

The dialbox, shown below, is composed of three major components:

(i)

The blue diamond-shaped box is bounded on 4 sides by triangles:

top-left:: displays the increment value for the current operation
top-right:: the rotation icon is a curly arrow
bottom-right:: the translation icon is a cross of 4 arrows
bottom-left:: the scaling icon is a large circle joined by a double-headed arrow to a small circle

The increment value triangle is always coloured yellow as is the current operation triangle; inactive operations are black.

By default, when the first hit is encountered rotation is the current operation with an increment value of 30.00 degrees.

(ii)

Within the blue box there are 4 arrows and the + and - signs:

x vertical down
y horizontal to right
z perpendicular to screen

for rotation about y use the up- and down-arrows

for rotation about z use the + and - signs

translation
- for translation use the left-, right-, up- and down-arrows
scaling
- for scaling up use the + sign, up-arrow or right-arrow
- for scaling down use the - sign, down-arrow or left-arrow

(iii)

At the centre of the dialbox is a yellow clock face with markings at the hour positions.

This analogue display is synchronised with the increment value in the top-left triangle.

Before describing the details of rotation, translation and scaling it should be pointed out that the same sequence of actions applies to all operations:

b. specify the operation increment or accept the current value

c. apply the operation

Rotation

Suppose that the first hit encountered results in the display shown below

The default operation type is rotation so the top-right triangle is coloured yellow to indicate that this is the active operation. In the yellow top-left triangle the default increment value is shown to be 30.00 degrees.

Bearing in mind that the z-axis is perpendicular to the screen now select the + sign. The crystal diagram is re-drawn rotated 30 degrees clockwise about the z-axis to produce the display shown in (b) on the facing page.

If you now select the - sign the original view will be restored since the - sign produces a counter-clockwise rotation about the z-axis.

The effects of rotation can be summarised thus:

x-axis vertical down:
- left-arrow moves left-half of diagram into the screen
- right-arrow moves right-half of diagram into the screen
y-axis horizontal to right:
- up-arrow moves top-half of diagram into the screen
- down-arrow moves bottom-half of diagram into the screen
z-axis perpendicular to screen:
- + sign rotates the diagram clockwise about the z-axis
- -sign rotates the diagram counter-clockwise about the z-axis

The increment value can be changed in two ways:

(a)

Select the increment triangle
Input rotation value:
Type 60 <R>
The increment triangle now shows a value of 60.00 degrees.
The clock now shows the arrow set at 2 o'clock.

The maximum rotation is 360 degrees, corresponding to a compete rotation of the clock arrow.

Each hour marking on the clock face corresponds to 30 degrees.

(b)

Select the position on the clock face corresponding to 6 o'clock.

The increment triangle now shows a value of 180.00 degrees.

Notes:

(i): If you type an increment value of 360 then the increment triangle shows a value of 0.00 degrees and the clock is set to 12 o'clock.
(ii): If you type an increment value of 390 then the increment triangle shows a value of 30.00 degrees and the clock is set to 1 o'clock.

Translation

When the translation operation is first selected (bottom-right triangle) the default increment value is shown as 2.50Å.

The maximum translation is 12Å, corresponding to a complete rotation of the clock arrow. Thus the default increment value of 2.50Å shows the clock arrow between 2 and 3 o'clock.

The effects of translation can be summarised thus:

up-arrow:: moves the diagram up the screen
down-arrow: moves the diagram down the screen
left-arrow: moves the diagram to the left
right-arrow: moves the diagram to the right

The increment value can be changed in two ways:

(a)

Select the increment triangle
```
Input translation value:
```
Type 5 <R>
The increment triangle now shows a value of 5.00Å
The clock now shows the arrow set at 5 o'clock.

(b)

Select the position on the clock face corresponding to 9 o'clock.

The increment triangle now shows a value of 9.00Å.

Notes:

(i): If you type an increment value of 12 then the increment triangle shows a value of 12.00Å and the clock is set to 12 o'clock.
(ii): If you type an increment value of 14 then the increment triangle shows a value of 12.00Å and the clock is set to 12 o'clock.

Scaling

When the scaling operation is first selected (bottom-left triangle) the default increment value is shown as 0.25.

The maximum scaling factor is 1.00, corresponding to a complete rotation of the clock arrow. Thus the default increment value of 0.25 shows the clock arrow at 3 o'clock.

The effects of scaling can be summarised thus:

+ sign or up-arrow or right-arrow: scales the diagram up
- sign or down-arrow or left-arrow: scales the diagram down

The increment value can be changed in two ways:

(a)

Select the increment triangle
```
Input scale value:
```
Type 0.5 <R>
The increment triangle now shows a value of 0.50.
The clock now shows the arrow set at 6 o'clock.

(b)

Select the position on the clock face corresponding to 9 o'clock.

The increment triangle now shows a value of 0.75.

Notes:

(i): If you type an increment value of 1 then the increment triangle shows a value of 0.99 and the clock is set to 11.59 o'clock.
(ii): If you type an increment value of 1.5 nothing happens.

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Volume 2 Chapter 4 Display Menus 3D SEARCH INFO PARAM AND SETUPS .