Zoom Subroutine for expanding spectra (ZO)
The Zoom subroutine allows the user to expand a spectrum horizontally to view details more easily. That is, you can "zoom" in and out. The user can enter the Zoom routine of NUTS in several ways: from the menu View / Zoom selection, from the command line with the command "ZO" and by double clicking the left mouse button.
Show me how to use Zoom.
On entering the Zoom subroutine, the menu choices change to display commands which are currently active. All commands can be accessed from the menus, with the exception of those which involve using the mouse.
Once in the Zoom subroutine, the mouse cursor changes into a small crosshair labeled ZO. While pressing and holding the left mouse button, "drag" the mouse and a region of the screen will be selected in inverse video. To jump to this expanded display, click the right mouse button or type Ctrl-E. The display window can be shifted left and right using the horizontal scroll bar at the bottom of the screen. The speed of this process depends on how many points are in the currently displayed region and on the speed of the computer. This may be impractical with slower computers. The horizontal scroll bar can be turned off in the NUTS.INI file.
The right mouse button toggles between full and expanded display while in the Zoom subroutine. While viewing an expanded region, the left mouse button can be used to select a still smaller region, and the right mouse button will then jump to this new expansion (Zoom within Zoom). The user can switch the display (from the Zoom routine or the NUTS base level) using Ctrl-F for full display or Ctrl-E for the expanded region display. While in Zoom, a specific frequency range of interest can be entered from the keyboard by typing F, which brings up a dialog box for entry of frequency limits in points, Hz or ppm.
The Zoom routine is exited with the <ENTER> keyboard key, returning the user to the NUTS base level. The current expanded region remains displayed on exiting Zoom.
- B Baseline Flatten by removing the DC level and linear tilt between the zoom limits. See also correcting the baseline.
- F Brings up a dialog box allowing entry of specific points or frequency limits for the expanded display.
- I Enter the integral ( ID ) subroutine. <Enter> will return to Zoom from the ID routine.
- Ctrl-Z Zero the data in (reals and imaginaries) between the start of the Zoom region and the end of the Zoom region. See also zeroing data.
- 1 Select current Zoom region for region 1 in PE phasing routine.
- 2 Select current Zoom region for region 2 in PE phasing routine.
- 0 – 9 Select the current Zoom region and assign it an identifying number 0-9. The region can be later recalled with the corresponding command Z0-Z9.
- Enter Exits the Zoom subroutine
Opens a dialog box for setting the frequency limits of the 10 Zoom regions. This accomplishes the same thing as setting regions within Zoom using 0-9.
Toggles the spectrum display to expanded display using the previously selected Zoom region. This is also available by selecting Type from the View menu. Control-F returns the display to the full spectrum.
Displays the entire spectrum (all real points). To jump to an expanded display, using previously defined frequency limits, type Ctrl-E. These commands operate in all subroutines and from Base level of program. This is also available by selecting Type from the View menu.
Changes the left and right frequency limits to the previous values. This allows zooming in on a peak and then jumping back to the previous view.
Recall one of ten separate, previously defined zoom regions. Up to 10 such regions can be defined, and those frequency limits saved for later recall. The frequency limits are defined in one of 3 ways:
- with the EZ (Enter Zoom limits) command
- within the Zoom subroutine using subcommands 0 – 9
- inside a macro with the command Set Zoom_Region
Commands Z0-Z9 recall the corresponding region. This is useful in designing automated processing.
This routine " registers" an arrayed set of 1D spectra, so that the chemical shift scale of all spectra is the same. This would be used, for example, when a series of spectra are acquired without a field/frequency lock, resulting in the spectra not lining up properly, as shown here:
First, choose a region of the spectrum whose largest peak will be used to align the spectra. The desired region is selected by setting the region while in ZOom with the # key where # is a digit between 0 and 9 (or, equivalently, by using the EZ command). The corresponding R# command will find the tallest peak in the region, and left or right shift the remaining spectra to make the tallest peak in this region of each subsequent spectrum have the same chemical shift. The ends of the shifted spectra are lost or set to zero. The data set above now looks like:
This routine works in the non-arrayed mode or Complex Arrayed Mode.
These commands work in the Arrayed Mode only. "Block averaged" data are collected as a series of 1D spectra and stored as slices of a 2D file. The series of files needs to be summed to yield a single spectrum, but it is necessary to compensate for any field shifts tha
t might have occurred during data acquisition, so that peaks line up correctly before being summed.
In the Zoom routine, select a region containing a peak which can be used for chemical shift registration, and assign it to a numbered Zoom region using one of the Zoom subcommands 0 – 9. Exit Zoom. Execute the Y# command (# is a number with the same value as the chosen zoom region). This performs the sum with appropriate adjustment so that the tallest peak in the chosen Zoom region lines up for each spectrum. The result will be a 1D spectrum, which has not yet been saved to the disk. When the summing is complete, NUTS also exits the arrayed mode, because the data has been converted to a 1D file, and arrayed mode is no longer appropriate.
The data set shown above results in this summed 1D spectrum:
Last updated: 12/8/06.