Creating customized apodization functions
See also window functions, reference deconvolution
Copies current data to the convolution filter buffer. This is useful for creating and applying customized apodization functions. (Do not confuse this with the Add/Subtract buffer.)
An apodization function can be created in different ways. One option is to build it within Nuts by first setting the current data points all equal to one with the 21 command. Alternatively, the ASCII import routine could be used to import a function created within a different application.
Once an apodization function is created, it can be copied to the convolution buffer with the DB command. The function is then viewed with the Convolution View (CV) command and applied with the Convolution Apply (CA) command. The latter 2 commands were created originally for use with functions created by the reference deconvolution operation (CF), but are also used for the general case of applying a function to an FID.
The data stays in the convolution buffer until replaced by another file or until Nuts is closed. The data may be copied back to the current data file with the Buffer to Data (BD) command.
Copies contents of the convolution filter buffer to the current data set, replacing the current data. The buffer must first have been loaded with the Data to Buffer (DB) command.
Replaces all data points in the current spectrum by one. The current spectrum is lost. Note that the line may appear off scale vertically. If the line is not visible, reduce the vertical scale with the right scroll bar, the Page Down key or the < key.
This command is useful for creating customized apodization functions. Once an apodization function is created, it can be copied to the convolution buffer with the Data to Buffer (DB) command. The function is then viewed with the Convolution View (CV) command and applied with the Convolution Apply (CA) command. The latter 2 commands were created originally for use with functions created by the reference deconvolution operation (CF), but are also used for the general case of applying a function to an FID.
2L -- Convert spectrum to line
Replaces the current spectrum with a line having a DC offset from zero. The actual value of the data points is 4096. The current spectrum is lost. Note that the line may appear off scale vertically. If the line is not visible, reduce the vertical scale with the right scroll bar, the Page Down key or the < key.
This command is useful for viewing apodization functions to optimize parameters. Dual Display can be used to view a trial apodization function simultaneously with a FID by first reading in the FID, placing it in the Add/Subtract buffer with the AL command and typing DD. Then execute 2L, which puts a line on the screen, and apply your chosen apodization function. Each time you want to display a different function, first type 2L again to re-set the line. To apply an apodization function to a FID, you must first read in the FID.
Adds a constant to all data points. Unlike DC, this command actually changes the data, not just where it is displayed on the screen. The amount added is equal to one-third of the difference between the largest and smallest point in the data set.
Last updated11/3/97.