Using the Cursor
While in the Base Level of the program (not in a subroutine), press and hold the left mouse button to display a red cross-hair cursor. This can be used to select a peak for chemical shift referencing. While holding down the mouse button, place the vertical cursor on the chosen peak and type P for ppm (or H for Hz). A dialog box is displaying into which can be entered a chemical shift in ppm (or Hz).
The horizontal position of the cross-hair cursor can be used to set the threshold for peak picking and for automatic integration. While holding down the left mouse button to display the cross-hair cursor, type T (for Threshold). This sets the Minimum Height to at the position of the horizontal cursor.
While the left mouse button is held down, a line of text is displayed in the lower left corner of the screen giving the cursor frequency as data point number, Hz and ppm:
Pt = 33225 2293.1 Hz 5.74 PPM
Frequency differences can also be displayed, useful for measuring coupling constants. This is done by setting a “marker” cursor to establish one frequency, then moving the cursor to the second frequency. There are 2 ways to set a marker cursor: 1) while holding down the left mouse button, type M on the keyboard, or 2) while holding down the left mouse button, click the right mouse button. Without releasing the left mouse button, move the cursor. The frequency difference is displayed in the lower right corner of the screen:
Difference: 41 Pts -9.5 Hz -0.02 PPM
The frequency at the cursor location and the frequency difference can be copied to the clipboard by typing C while the desired information is displayed. The clipboard contents is displayed on the screen until the mouse button is released.
In 2D display mode (intensity or contour plot), holding down the left mouse button displays a full-screen cross-hair cursor. The frequency coordinates of the cursor position are displayed at the bottom of the screen. If C is typed while the mouse button is held down, the frequency coordinates of the cursor location are placed into the clipboard and displayed on the screen. The chemical shifts can also be placed into a Data Table to build a table of assignments.
A text annotation (“Note“) can be created, into which the currently displayed frequency information is placed. This is done by typing N while the desired information is displayed. The Note is “locked” to the cursor frequency, so its position on the screen will change as the displayed spectral region changes. Multiple Notes can be created in this manner. Overlap is avoided by displaying the Notes at different vertical positions. They can also be moved from within the Notes subroutine.
The cursor can also be used to display and scroll through slices, overlaid on the contour plot. See details.
Keyboard commands that work with the cursor:
C – Copy frequency information to the clipboard
N – Create a Note containing the frequency information
M – Set a marker cursor (not active in 2D display mode)
P – Set a ppm value at the cursor position (if in 1D display mode, only the shift for the horizontal dimension can be set)
H – Set a Hz value at the cursor position (if in 1D display mode, only the shift for the horizontal dimension can be set)
T – Set the threshold (minimum height) used for peak picking (for 1D spectra)
Last updated: 2/20/08