# Book: The Art of VA Filter Design 2.1.2

DSP, Plug-in and Host development discussion.
KVRAF
5265 posts since 18 Jul, 2002
Synthesizers • Bliss sampler • Effects • Soundware
https://www.discodsp.com/

KVRian

Topic Starter

1307 posts since 12 Apr, 2002
discoDSP wrote:
Tue Feb 25, 2020 1:39 am
Mirror: https://www.discodsp.net/VAFilterDesign_2.1.2.pdf
Thanks! (That was fast )

KVRist
40 posts since 28 Nov, 2020
wow thank you all very much for this book and the bugfixes.
I just love DSP stuff

The book contains a lot of graphs, which enhances the understanding.

KVRist
40 posts since 28 Nov, 2020
One thing which pisses me of about the usual academic literate is that figures and tables aren't on the same page even if the size of these allows it.

ex:
3.8 Cutoff prewarming
Suppose we are using the lowpass filter structure in Fig. 3.12 and we wish to have its cutoff atωc.

The images are on the next page, I hate this presentation and saw it in all kinds of literature.

KVRAF
12436 posts since 7 Dec, 2004
When you print the document or display it in the usual wide-screen dual-page format, most papers and books are structured such that you can see the referenced figures on the opposite page. This is not always possible in a physical medium although using software it is trivial to display any two or more pages together at once.
Free plug-ins for Windows, MacOS and Linux. Xhip Synthesizer v8.0 and Xhip Effects Bundle v6.7.
The coder's credo: We believe our work is neither clever nor difficult; it is done because we thought it would be easy.
Work less; get more done.

KVRAF
6402 posts since 12 Feb, 2006 from Helsinki, Finland
aciddose wrote:
Sat Dec 12, 2020 10:03 pm
When you print the document or display it in the usual wide-screen dual-page format, most papers and books are structured such that you can see the referenced figures on the opposite page. This is not always possible in a physical medium although using software it is trivial to display any two or more pages together at once.
I think most academic papers just use the default LaTeX templates and only tweak if there are obvious large problems. Publications might do a bit more once in a while, but especially pre-prints tend to be whatever LaTeX produces out of the box (which arguably is usually somewhat reasonable at least in terms of paper as the medium). Whether or not LaTeX prefers the opposite page, I'm not sure, but it might actually be something it prefers in certain cases.
Preferred pronouns would be "it/it" because according to this country, I'm a piece of human trash.

KVRian
982 posts since 25 Sep, 2014 from Specific Northwest
Usually, it takes a human touch to even come close to perfect figure distribution. Sometimes, figures come faster than the text and need to be clustered on the opposing page; sometimes, figures get widowed and have to be on the following page, after a page turn. It can take some manual fiddling to correct that, but you often end up with huge swaths of blankness, which can make your text go past the allotted signature count, if your text is going to the printers.

Basically, occasionally, the reader is going to suffer for expediency's sake.

KVRAF
12436 posts since 7 Dec, 2004
For clarity, the intent of my post was to say: "Do it yourself."

I was pointing out that it is usually impossible to achieve anything remotely like optimal figure distribution, but it is extremely easy to open two instances of the document (pages!) side-by-side and view any figure(s) at any time in the standard widescreen display ratios.
Free plug-ins for Windows, MacOS and Linux. Xhip Synthesizer v8.0 and Xhip Effects Bundle v6.7.
The coder's credo: We believe our work is neither clever nor difficult; it is done because we thought it would be easy.
Work less; get more done.

KVRer
4 posts since 11 Mar, 2014
I like the figure distribution. I printed chapter two out. A5 for one page, so that i have two pages on A4 page. (with duplex you can even have 4 pages in sight, this should be enough to see any figures, which could be need for understanding) The margins are perfect to put notes there.

So far i love what i read. Very good book.

(going to post any typos and comments here)

Just an observation:
Something i noticed, the first integral in chapter 1.5 (and later on), in the integral it doesnt makes if one writes $j \infty$ or $\infty$, because well $\infty$ absorbs everything (unless dealing with highter infinities, which dont so here anyway), even $\infty \cdot \infty \equiv \infty$. (but i assume that is only to indicate that we are actual doing complex integration on complex axis, over the whole axis - in mathematics this would be handled by a limit process to make this clear, but one who reads this book, should maybe be aware of that?)

So far so good.

KVRAF
6402 posts since 12 Feb, 2006 from Helsinki, Finland
Ameyah wrote:
Tue Jun 22, 2021 1:56 am
Just an observation:
Something i noticed, the first integral in chapter 1.5 (and later on), in the integral it doesnt makes if one writes $j \infty$ or $\infty$, because well $\infty$ absorbs everything (unless dealing with highter infinities, which dont so here anyway), even $\infty \cdot \infty \equiv \infty$. (but i assume that is only to indicate that we are actual doing complex integration on complex axis, over the whole axis - in mathematics this would be handled by a limit process to make this clear, but one who reads this book, should maybe be aware of that?)
I'm not entirely sure I understand what you are trying to say here (is this about infinity on the Riemann-sphere being a point?), but the integral in question appears to be the Fourier transform as an integral over s taken over the imaginary axis (ie. really an indefinite integral, but with bounds used to clarify the line of integration) and I feel like this is probably an instance of "intentional abuse of notation" in order to highlight the relationship between Laplace and Fourier transforms.
Preferred pronouns would be "it/it" because according to this country, I'm a piece of human trash.

KVRer
4 posts since 11 Mar, 2014
mystran wrote:
Tue Jun 22, 2021 5:07 am
Ameyah wrote:
Tue Jun 22, 2021 1:56 am
Just an observation:
Something i noticed, the first integral in chapter 1.5 (and later on), in the integral it doesnt makes if one writes $j \infty$ or $\infty$, because well $\infty$ absorbs everything (unless dealing with highter infinities, which dont so here anyway), even $\infty \cdot \infty \equiv \infty$. (but i assume that is only to indicate that we are actual doing complex integration on complex axis, over the whole axis - in mathematics this would be handled by a limit process to make this clear, but one who reads this book, should maybe be aware of that?)
I'm not entirely sure I understand what you are trying to say here (is this about infinity on the Riemann-sphere being a point?), but the integral in question appears to be the Fourier transform as an integral over s taken over the imaginary axis (ie. really an indefinite integral, but with bounds used to clarify the line of integration) and I feel like this is probably an instance of "intentional abuse of notation" in order to highlight the relationship between Laplace and Fourier transforms.
definitely an abuse of notation! i am not sure how other non mathematician feel about such notation. It was driving me crazy

Anyway, it was just a comment or remark and im not sure how mathematics is/was taught for people being active in the field of DSP/electric engineering.

Hopefully i can continue to read more tomorrow.

KVRian

Topic Starter

1307 posts since 12 Apr, 2002
Ameyah wrote:
Tue Jun 22, 2021 1:56 am
(but i assume that is only to indicate that we are actual doing complex integration on complex axis, over the whole axis - in mathematics this would be handled by a limit process to make this clear, but one who reads this book, should maybe be aware of that?)
Your assumption is correct. Some justification for the used notation:
On one hand infinity absorbs everything in complex notation. On the other hand we have +inf and -inf in real domain, which suggests it doesn't "absorb everything". j*inf implies a "real positive" infinity multiplied by j, the same like +inf or -inf. Also, with improper integrals inf is a common shorthand notation for avoiding writing an explicit limit. I realize my usage of it here is uncommon, but actually IMHO it's 100% (or maybe 99%) consistent with the other usages of inf for the reasons explained above. Frankly speaking, I'm not really sure why this is not commonly used.

KVRAF
6402 posts since 12 Feb, 2006 from Helsinki, Finland
Z1202 wrote:
Tue Jun 22, 2021 11:01 pm
I realize my usage of it here is uncommon, but actually IMHO it's 100% (or maybe 99%) consistent with the other usages of inf for the reasons explained above. Frankly speaking, I'm not really sure why this is not commonly used.
I'm not a mathematician, but for what it's worth I always thought the intent here was clear, even if the notation might be slightly unconventional. When I said "intentional abuse of notation" above, that should really be interpreted as "fairly typical case of using slightly informal short-hand notation where there is no true risk of confusion" as is commonly done in order to let the reader focus on the actual message rather than deciphering notational rigour.

ps. Basically my position is that your notation here improves clarity at the cost of potentially being a little hand-wavy about the nature of infinities (or integral bounds, or whatever the real objection here happens to be). I personally think it's a clear net-win.
Preferred pronouns would be "it/it" because according to this country, I'm a piece of human trash.

KVRian
1473 posts since 11 Nov, 2009 from Northern CA
mystran wrote:
Wed Jun 23, 2021 5:20 am
I'm not a mathematician
Well, you surely could have fooled me!

KVRer
4 posts since 11 Mar, 2014
Z1202 wrote:
Tue Jun 22, 2021 11:01 pm
Ameyah wrote:
Tue Jun 22, 2021 1:56 am
(but i assume that is only to indicate that we are actual doing complex integration on complex axis, over the whole axis - in mathematics this would be handled by a limit process to make this clear, but one who reads this book, should maybe be aware of that?)
Your assumption is correct. Some justification for the used notation:
On one hand infinity absorbs everything in complex notation. On the other hand we have +inf and -inf in real domain, which suggests it doesn't "absorb everything". j*inf implies a "real positive" infinity multiplied by j, the same like +inf or -inf. Also, with improper integrals inf is a common shorthand notation for avoiding writing an explicit limit. I realize my usage of it here is uncommon, but actually IMHO it's 100% (or maybe 99%) consistent with the other usages of inf for the reasons explained above. Frankly speaking, I'm not really sure why this is not commonly used.
Okay, i understand. We often write simply \C below the intergral, which indicates that we integrate over the whole complex plane. But this is probably even more abstract to the non mathematically reader.
Alright i think then i understand the notation and see that it is fine. I am just ruined a bit by to mathematically notation.

To the diagrams, i am putting my own notes together, is this plain tikz or did you use some extra latex package? (i tried blox and i can not put the label y(n) to the right as intented by DSP diagrams.)

Also thanks for answering so quickly.