Help for Sliders

CHANGING PARAMETER VALUES:
There many ways to change the value of the variables controlled by the sliders.

• With the left mouse button alone:
  • Put the cursor on the little box in the slot below the label (the slider "handle"), hold down the mouse button, and drag the handle until the desired value appears in the box. The slider handle can be pulled beyond the range of the gray bar to set values outside of the nominal range of the slider.
  • When the slider is off scale you can still grab hold of a little piece of the handle and either pull it further off scale, or return it towards the normal range.
  • Click the mouse button in the ``trough'', the gray bar containing the handle, to move the handle towards the cursor by 10% of the full range. Holding the button down, the slider will continue to move in steps of the same size, even continuing beyond the nominal range of the slider.
  • If the slider is off scale, clicking in the trough will return the slider towards the normal range. Hold down the button to continue the return.
  • Click either of the small triangles to move the handle by a small increment. Holding the button down, the slider will continue to move in steps of the same size, even continuing beyond the nominal range of the slider.
  • When the slider is off scale, it may still be incremented in either direction in small steps by clicking on the small triangles.
  • The small triangles do not work with the logarithmic sliders.
• With the Control key pressed:
  a click in the trough on either side of the slider takes the slider to the corresponding end of the range. (This feature will not work on linear sliders for which the nominal end of the slider range is outside the range allowed by the program. I.e., a slider with nominal range 0 to 10 for a variable restricted to be "greater than zero" will control-click to the 10 but not to the zero end of the range. If the restriction is to "zero or positive", the control-click will work to both ends.)
• With the middle mouse button:
  or the ([left] button + Shift on the [PC] or Mac), a click in the trough moves the slider to the position of the cursor.
• By typing:
  Type a new value in the entry box over the slider, which displays the current value. To activate the entry box so that you can type in it, click in it with the mouse button. (A double click clears the current contents from the box.) When the number in the window is changed, the text turns red to indicate that the current value of the variable used by the program does NOT equal the number in the box. To change the variable, press the Enter key. If the typed number is not a valid value for that variable, (a decimal number for something that should be an integer, a number which is too big or too small) a message box will pop up to tell you, and won't go away until you click ``OK'' or ``close'', or press the Enter key. After this, go back and fix the slider, or else the program will run with the old parameter value.

ALTERING THE SLIDER:
Several parameters characterizing the slider may be changed by clicking in the small rectangular box at the right end of the slider. Options in the configure window include:

• minimum: sets the left hand limit of the slider range.
• maximum: sets the right hand limit of the slider range.
• increment: sets the size of the small incremental steps triggered by clicking the small triangles at the end of the slider.
• close: closes the configure dialog box.

BUGS AND IDIOSYNCRASIES:

• Sliders come in two flavors, linear (the more usual) and log (for parameters that vary over a wide range). The linear sliders tend to behave better than the log sliders. Typing numbers in the log sliders often saves frustration.
• Some programs alter their displays immediately after change of a slider setting. Others wait until a calculate or similar button is pressed. In the case of the immediate update, the slider response may seem erratic. This is because it is waiting for the program to catch up before it will accept a new value.
• If the increment in the slider configure box is set to less than 1% of the slider range, the step size of the coarse clicks may vary from the 10% value. This problem will vary with platform.
• Occasionally a slider will throw a tantrum and try to run away. Double click in the entry box, type in any value, and enter to get the slider back under control.
• We have occasionally observed freezes, crashes, and runaway loops induced by too rapid clicking in the slider troughs. Don't be in too much of a hurry.