These commands adjust the display of the data, and do not actually change values of data points.
Scaling the spectrum display
The vertical scale of the displayed data can be adjusted in several ways: by using right hand scroll bar, with the greater than and less than keys ( > and < ) for changes by factors of 2, with the Page Up and Page Down keys and with the cursor up and down arrow keys for finer adjustment.
There are also several commands which change or affect the display scale:
- AC Amplitude change; enter multiplying factor
Ctrl-Y Scales the tallest displayed peak to be full scale.
MF Scales the tallest displayed peak to be full scale.
S0 Scale Zero; sets scroll bar to zero
FS Fix scale
CS Clear fixed scale
It is important to understand that these commands affect only display of the data. They do not change the values of the data points. NUTS does all operations in floating point, rather than integer, arithmetic. This eliminates the need for a scaling or normalization constant which is necessary for data represented as integers, because there is a limited dynamic range for integers. Therefore, the absolute values of the data points in NUTS can be directly compared from spectrum to spectrum without the need for fixing Absolute Intensity.
Opens a dialog box for input of a vertical scaling factor. This command is also available from the View menu.
When used in a macro, the current value for the scaling factor is applied, without asking for user input. Therefore, to use AC in a macro, first use the command SET AC to enter a value, then use the AC command to apply that scaling.
The scaling factor is applied to the spectrum as it is currently displayed. This allows the user to change the vertical scale by a specific factor. The vertical scale can also be adjusted with the right hand scroll bar, with the Page Up and Page Down keys, with the up and down cursor keys and with the < and > keys.
Adjusts the vertical scaling so that the largest peak in the currently displayed region becomes full scale. This command is also available from the View menu. This command is active in all subroutines. To use Ctrl-Y in a Link or Macro, use " ^Y ". The vertical scale can also be adjusted with the right hand scroll bar, with the Page Up and Page Down keys, with the up and down cursor keys and with the < and > keys. The Amplitude Change (AC) command allows input of a specific scaling factor.
This disables automatic scaling of the data display, allowing a series of spectra to be displayed with the same vertical scale. In its default operation, NUTS scales the data using two different scaling factors. One scaling factor is determined by the position of the right scroll bar. The other scale factor is automatically determined by NUTS and is the absolute difference between the minimum and maximum of the current spectrum. When the FS command is given, the latter number is fixed at the current level until the CS (Clear Scaling) command is given. This allows other spectra to be loaded and their amplitudes directly compared.
This scaling affects display only. NUTS performs all operations in floating point, not integer math. This obviates the need for applying and keeping track of a scaling or normalization constant in order to compare data. Note that setting minimum height for peak picking using the cursor does not work properly when FS is enabled.
Clears display scaling previously fixed by FS command.
Returns the right-hand scroll bar to zero and removes all vertical scaling applied with either the scroll bar or keyboard (page up/down or <> keys).
Allows the user to override the default value for the vertical position of the spectrum on the screen. This is useful for displaying spectra with negative peaks. After entering the DC routine, a scroll bar on the left side of the NUTS window appears and can be used to adjust the vertical position of the spectrum display. Typing <Enter> exits the DC routine, and the new vertical position of the spectrum display remains the default until reset or the program is restarted. To reset the vertical position back to the bottom of the screen, enter the DC routine and type 0 (zero). The offset can be set to a specific fraction of the screen by typing a single digit (1, 2… 9) while in the DC routine. For example, typing 2 moves the display approximately 20% up the screen.
Ttype <Enter> to exit the DC routine.
Last updated: 6/22/07.