Digital lowpass - highpass filters

[Death Eater Dan]

Can anyone direct me to a site that explains why when you invert every
second sample of a digital filter you can change from low pass to high pass
filters. I dont understand it and my text books do not mention it.

Cheers,
Dan.

 

[Richard Freeman]

"Death Eater Dan" <DeathEater@Hogwarts.com> wrote in message
news:3f4b1012$0$10355$afc38c87@news.optusnet.com.au...

Can anyone direct me to a site that explains why when you invert every
second sample of a digital filter you can change from low pass to high
pass
filters. I dont understand it and my text books do not mention it.

Got Excel ? or Lotus 1,2,3 ? try it on a spreadsheet it all starts to make
more sense then.
Digital Filters are Mathematical Constructs not Engineering ones and you
need to analyse them using mathemical tools.

For an Excellent Text book ( in fact one of the few that made any sense as
most of them are written by mathematicians) on Digital Signal Processing may
I reccomend this book : http://www.dspguide.com/ Not readily available in
Australia unfortunately but readily available from Amazon (it is not cheap
but well worth every cent)

 

[Newsy]

"Richard Freeman" <deletemerichard@atps.net> wrote in message
news:3f4bed0a$1_1@news.iprimus.com.au...

"Death Eater Dan" <DeathEater@Hogwarts.com> wrote in message
news:3f4b1012$0$10355$afc38c87@news.optusnet.com.au...
Can anyone direct me to a site that explains why when you invert every
second sample of a digital filter you can change from low pass to high
pass
filters. I dont understand it and my text books do not mention it.

Got Excel ? or Lotus 1,2,3 ? try it on a spreadsheet it all starts to make
more sense then.
Digital Filters are Mathematical Constructs not Engineering ones and you
need to analyse them using mathemical tools.

For an Excellent Text book ( in fact one of the few that made any sense as
most of them are written by mathematicians) on Digital Signal Processing
may
I reccomend this book : http://www.dspguide.com/ Not readily available in
Australia unfortunately but readily available from Amazon (it is not cheap
but well worth every cent)

Great link Richard.

You didn't mention the free download of the entire book!

Rod

 

[Defibrillator]

From the site:

IMPORTANT NOTE:
Acrobat 5.0 & Acrobat Reader 5.0 (released in March 2001) contain a bug that
prevents them from properly displaying the equations contained in these
files. This bug was corrected in a later release, Acrobat Reader 5.0.5 (Dec.
2001), which can be obtained by clicking on the icon.


"Richard Freeman" <deletemerichard@atps.net> wrote in message
news:3f4c080b$1_1@news.iprimus.com.au...

"Newsy" <rlg000@hotmail.com> wrote in message
news:3f4bf722@duster.adelaide.on.net...

"Richard Freeman" <deletemerichard@atps.net> wrote in message
news:3f4bed0a$1_1@news.iprimus.com.au...

"Death Eater Dan" <DeathEater@Hogwarts.com> wrote in message
news:3f4b1012$0$10355$afc38c87@news.optusnet.com.au...
Can anyone direct me to a site that explains why when you invert
every
second sample of a digital filter you can change from low pass to
high
pass
filters. I dont understand it and my text books do not mention it.

Got Excel ? or Lotus 1,2,3 ? try it on a spreadsheet it all starts to
make
more sense then.
Digital Filters are Mathematical Constructs not Engineering ones and
you
need to analyse them using mathemical tools.

For an Excellent Text book ( in fact one of the few that made any
sense
as
most of them are written by mathematicians) on Digital Signal
Processing
may
I reccomend this book : http://www.dspguide.com/ Not readily available
in
Australia unfortunately but readily available from Amazon (it is not
cheap
but well worth every cent)

Great link Richard.

You didn't mention the free download of the entire book!

I didnt because unfortunately many of the Formulae and diagrams are
obfuscated ( big word I heard somewhere - hope I have the meaning right

in the free Download but it is enough to prove the book aint a theoretical
mathematics tome and is worth the $100 it cost (and believe me it is worth
buying - BTW I am not nor do I know the author )

Regards
Richard Freeman

 

[Newsy]

"Defibrillator" <nospam@for.me> wrote in message
news:2VX2b.66073$bo1.32853@news-server.bigpond.net.au...

From the site:

IMPORTANT NOTE:
Acrobat 5.0 & Acrobat Reader 5.0 (released in March 2001) contain a bug
that
prevents them from properly displaying the equations contained in these
files. This bug was corrected in a later release, Acrobat Reader 5.0.5
(Dec.
2001), which can be obtained by clicking on the icon.

I'm using 6 Pro, so I didn't worry about the message.
Rod