Processing Data with VnmrJ
- Select AcquireTab / AcquisitionPage and make note of number of points in F3 and increments in F1/F2
- Select ProcessTab and “in t2” for 2D OR “in t3” for 3D experiment.
- Apply window function by pressing “Gaussian” button.
- Adjust phase as necessary using only left mouse number. (Note: rp should equal 0).
- Now select “in t1” page (and/or “in t2” if 3D experiment)
- From “AutoSetWeighting) popup select window function (i.e., Gaussian).
- If you want to do linear prediction, check the checkbox and press “AutoLP x2” button.
- You may set the transform sizes to 2x the number of points in that dimension, but the default may be OK.
- Then under “Transforms” select Weighted -> “F2 x F1 2D” (or “F3 x F1 2D, etc.)
- You may repeat for the 3rd dimension.
Other VNMR Processing Options
- use as small a bandwidth as necessary (100 to 500)
- coefs value from 100 to 200
- don't bother trying polynomial function
- offset only needed if tof not adjusted properly
- can be used to apply a cicular shift on data collected with a small spectral width
- setlp2(desired ni2, acquired ni2, #fixed)
- desired ni2 is the final extended data size
- aquired ni2 is total # of increments used as a basis
- # fixed is the # of initial points in t2 to be predicted (usually 1 to 4)
- try with different # fixed to find best values
- dc2d('f2') to correct for DC offsets along f2
- applied after processing data
- specdc3d is a string variable usually set to 'nnn'
- set a character to 'y' to activate DC offset correction along a particular dimension
- 1st character is for 1st dimension, etc
- set before doing the 3D transform