Menu Item |
Filter->Create/Edit Filter->Lowpass |
Macro Command |
Create Lowpass Filter(width,Start) |
Shortcut Key/Button |
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Other Keys/Buttons |
'V', Up, Down, Left, Right, 'M', 'N', Escape, Tab, Return |
Title Line Information |
LowpassFilter(width,Start) |
Command Line Option |
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Progress Box |
LowPass(width,Start) |
File Name Abbreviation |
LPF |
Input(s) |
DFT Input Buffer |
Output goes to |
Out and DFT Output Buffer |
Quick Undo information saved |
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Default Values |
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Value Range |
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Display Mode |
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The Macro and Menu versions are not the same. The Macro version creates a filter but will not apply it.
The Menu version crteates a filter and dispplays a representation of it on the screen for you to adjust the visual shape of it. High frequency components are to the lower right, low frequency to the upper left. The width parameter adjusts how rapidly the filter changes from white to black, i.e. passing to not passing the corresponding frequencies. The Start parameter sets the width of the white region at the upper left i.e. the position of the beginning of the decay from white to black. Use the Up and Down arrows to choose which param to adjust, if an output mode other than normal is selected it's paramater can be found in this way too. 'V' is used to enter a numeric value for a parameter, or the usual keys to adjust values interactively. Press Return and the representation disappears and the Filter Input Buffer is filtered using the current settings. You can still adjust the filter parameters as described above. Press Return again and the filter design process is complete. You can reuse a filter once designed by specifying a different DFT Input or Output or by using one of the DFT Immediate Commands. The result of filtering is placed in Out., and a copy in the DFT Output buffer.