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I am working on a new DSP textbook using Python. Comments are welcome!

Started by AllenDowney January 5, 2015
Rick Lyons <R.Lyons@_bogus_ieee.org> wrote:

(snip)

> [1] I vote that you use "spectra" instead of "spectrums."
It might be that some plurals aren't used much, but spectra is pretty common. (At least in the spectroscopy world.)
> [2] I suggest you go through your material and change > all instances of the word "frame" to the > word "sample." Why use the non-standard, and > possibly confusing, word "frame" for a single number > when the rest of the world of DSP literature uses > the word "sample" to describe a single number?
> [3] I suggest you go through your figures (like > Figure 2.6 for example) and show all discrete > sequences (discrete signals) as a series of dots > rather than as continuous curves. Imagine how confused > a DSP beginner will be when they see a picture of a > continuous (analog) signal and you call it a "sampled > signal" or a "sampled waveform." This is a big deal. > For the sake of your readers, please do not ignore > this suggestion.
Without having actually looked, I might say that a continuous curve with dots at sample points could work, but I agree with Rick, you can't just have the curve. (Unless the sample points are so close that you can't resolve the dots.) -- glen
On 1/9/2015 12:50 PM, Eric Jacobsen wrote:
> On Fri, 09 Jan 2015 12:17:04 -0500, rickman <gnuarm@gmail.com> wrote: > >> On 1/9/2015 11:29 AM, Eric Jacobsen wrote: >>> On Thu, 08 Jan 2015 23:12:56 -0500, rickman <gnuarm@gmail.com> wrote: >>> >>>> On 1/8/2015 10:14 AM, Eric Jacobsen wrote: >>>>> On Thu, 08 Jan 2015 01:01:46 -0500, rickman <gnuarm@gmail.com> wrote: >>>>> >>>>>> On 1/7/2015 7:02 PM, Les Cargill wrote: >>>>>>> rickman wrote: >>>>>>>> On 1/6/2015 8:19 PM, Les Cargill wrote: >>>>>>>>> Piergiorgio Sartor wrote: >>>>>>>>>> On 2015-01-06 20:43, Tim Wescott wrote: >>>>>>>>>> [...] >>>>>>>>>>> English is moving toward pluralizing Latin words with an 's' >>>>>>>>>>> instead of >>>>>>>>>>> the Latin rules. Now that we've abandoned making people learn Latin >>>>>>>>>>> before they can be considered learned, I don't think you can hold >>>>>>>>>>> back the >>>>>>>>>>> tide. >>>>>>>>>> >>>>>>>>>> There is another problem too. >>>>>>>>>> >>>>>>>>>> For example, "virus" (poison) has *no* plural >>>>>>>>>> in Latin, so how do you say "two virus(es)"? >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> In English, "virii". >>>>>>>> >>>>>>>> If you check multiple references you will find virii as being deprecated >>>>>>>> for viruses. In fact, it was never virii since as has already been >>>>>>>> pointed out virus is from a latin word which has *no* plural form. The >>>>>>>> English plural form is viruses. Virii is a trendy word mostly in the >>>>>>>> computer community. >>>>>>>> >>>>>>> >>>>>>> "Deprecated" in this case meaning it once was proper and is no more? >>>>>>> Bah! :) >>>>>>> >>>>>>> I don't particularly *care* about usage in Latin. English is a >>>>>>> living neologistic language that grows rather quickly. ROMANES >>>>>>> EUNT DOMUS for the Python literate out there... >>>>>>> >>>>>>> I am pretty sure ( as you say ) it's a techie neologism, but it's >>>>>>> perfectly good English, regardless of what any dictionary says or does >>>>>>> not say. >>>>>>> >>>>>>> Of course, if you're in a formal situation where the dictionary *does* >>>>>>> hold final sway, then I suppose you are stuck :) >>>>>>> >>>>>>> They used to say "ain't ain't a word" and then it was one. >>>>>> >>>>>> All I know is virii ain't a word in any language. >>>>> >>>>> Apparently it is. It's been used here several times and people >>>>> understood the meaning. >>>> >>>> Sorry, that doesn't make it a word. Lots of people understand pwnd and >>>> any manner of language specific to a small group. That doesn't make it >>>> a part of any language. >>>> >>>> -- >>>> >>>> Rick >>> >>> Usage of words define them. Dictionaries just reflect the most common >>> and established usage. >>> >>> Glorbfutz is a word. So is snurglefop. If they're not words, what >>> are they? Gibberish consists of words, they're just not very useful. >> >> Ok, by your definition everything is a word. End of discussion. > > Way to miss the point. > > I agree with this guy:
No, you miss the point. I don't care what "this guy" says. Please discuss this with someone who does care what your "guy" says. -- Rick
>Rick Lyons <R.Lyons@_bogus_ieee.org> wrote: > >(snip) > >> [1] I vote that you use "spectra" instead of "spectrums." > >It might be that some plurals aren't used much, but spectra is >pretty common. (At least in the spectroscopy world.) > >> [2] I suggest you go through your material and change >> all instances of the word "frame" to the >> word "sample." Why use the non-standard, and >> possibly confusing, word "frame" for a single number >> when the rest of the world of DSP literature uses >> the word "sample" to describe a single number? > >> [3] I suggest you go through your figures (like >> Figure 2.6 for example) and show all discrete >> sequences (discrete signals) as a series of dots >> rather than as continuous curves. Imagine how confused >> a DSP beginner will be when they see a picture of a >> continuous (analog) signal and you call it a "sampled >> signal" or a "sampled waveform." This is a big deal. >> For the sake of your readers, please do not ignore >> this suggestion. > >Without having actually looked, I might say that a continuous >curve with dots at sample points could work, but I agree with >Rick, you can't just have the curve. (Unless the sample points >are so close that you can't resolve the dots.) > >-- glen >
I see continuous or discrete curve irrelevant. All matlab plots (and possibly other tools) produce default continuous curve. e.g. freqz(h,1) Kaz _____________________________ Posted through www.DSPRelated.com
On Sat, 10 Jan 2015 03:24:37 -0600, "kaz" <37480@dsprelated> wrote:

>>Rick Lyons <R.Lyons@_bogus_ieee.org> wrote: >> >>(snip) >> >>> [1] I vote that you use "spectra" instead of "spectrums." >> >>It might be that some plurals aren't used much, but spectra is >>pretty common. (At least in the spectroscopy world.) >> >>> [2] I suggest you go through your material and change >>> all instances of the word "frame" to the >>> word "sample." Why use the non-standard, and >>> possibly confusing, word "frame" for a single number >>> when the rest of the world of DSP literature uses >>> the word "sample" to describe a single number? >> >>> [3] I suggest you go through your figures (like >>> Figure 2.6 for example) and show all discrete >>> sequences (discrete signals) as a series of dots >>> rather than as continuous curves. Imagine how confused >>> a DSP beginner will be when they see a picture of a >>> continuous (analog) signal and you call it a "sampled >>> signal" or a "sampled waveform." This is a big deal. >>> For the sake of your readers, please do not ignore >>> this suggestion. >> >>Without having actually looked, I might say that a continuous >>curve with dots at sample points could work, but I agree with >>Rick, you can't just have the curve. (Unless the sample points >>are so close that you can't resolve the dots.) >> >>-- glen >> > >I see continuous or discrete curve irrelevant.
Are you saying that graphically depicting a discrete sequence with what looks like a continuous curve is acceptable?
>All matlab plots (and >possibly other tools) produce default continuous curve. e.g. freqz(h,1)
You're joking, right. All of Matlab's plotting capabilities consist of plotting straight lines from one discrete amplitude value to another discrete amplitude value. Zoom in on your freqz(h,1) plot and you'll see what I mean. Actually, there's no such thing as a continuous curve on a computer screen, but that's not the issue here. What I'm saying is tutorial material should not depict a discrete signal (a discrete sequence) with what looks like an analog (continuous) curve. Surely you agree with that. (And don't call me "Shirley.") By the way kaz, check out Matlab's 'stem(x)' command. [-Rick-]
http://youtube.com/watch?v=kN5orElkXdY
http://m.youtube.com/watch?v=zaYseBJuruk
On Friday, January 9, 2015 at 12:50:40 PM UTC-5, Eric Jacobsen wrote:
> On Fri, 09 Jan 2015 12:17:04 -0500, rickman <gnuarm@gmail.com> wrote: > > >On 1/9/2015 11:29 AM, Eric Jacobsen wrote: > >> On Thu, 08 Jan 2015 23:12:56 -0500, rickman <gnuarm@gmail.com> wrote: > >> > >>> On 1/8/2015 10:14 AM, Eric Jacobsen wrote: > >>>> On Thu, 08 Jan 2015 01:01:46 -0500, rickman <gnuarm@gmail.com> wrote: > >>>> > >>>>> On 1/7/2015 7:02 PM, Les Cargill wrote: > >>>>>> rickman wrote: > >>>>>>> On 1/6/2015 8:19 PM, Les Cargill wrote: > >>>>>>>> Piergiorgio Sartor wrote: > >>>>>>>>> On 2015-01-06 20:43, Tim Wescott wrote: > >>>>>>>>> [...] > >>>>>>>>>> English is moving toward pluralizing Latin words with an 's' > >>>>>>>>>> instead of > >>>>>>>>>> the Latin rules. Now that we've abandoned making people learn Latin > >>>>>>>>>> before they can be considered learned, I don't think you can hold > >>>>>>>>>> back the > >>>>>>>>>> tide. > >>>>>>>>> > >>>>>>>>> There is another problem too. > >>>>>>>>> > >>>>>>>>> For example, "virus" (poison) has *no* plural > >>>>>>>>> in Latin, so how do you say "two virus(es)"? > >>>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> In English, "virii". > >>>>>>> > >>>>>>> If you check multiple references you will find virii as being deprecated > >>>>>>> for viruses. In fact, it was never virii since as has already been > >>>>>>> pointed out virus is from a latin word which has *no* plural form. The > >>>>>>> English plural form is viruses. Virii is a trendy word mostly in the > >>>>>>> computer community. > >>>>>>> > >>>>>> > >>>>>> "Deprecated" in this case meaning it once was proper and is no more? > >>>>>> Bah! :) > >>>>>> > >>>>>> I don't particularly *care* about usage in Latin. English is a > >>>>>> living neologistic language that grows rather quickly. ROMANES > >>>>>> EUNT DOMUS for the Python literate out there... > >>>>>> > >>>>>> I am pretty sure ( as you say ) it's a techie neologism, but it's > >>>>>> perfectly good English, regardless of what any dictionary says or does > >>>>>> not say. > >>>>>> > >>>>>> Of course, if you're in a formal situation where the dictionary *does* > >>>>>> hold final sway, then I suppose you are stuck :) > >>>>>> > >>>>>> They used to say "ain't ain't a word" and then it was one. > >>>>> > >>>>> All I know is virii ain't a word in any language. > >>>> > >>>> Apparently it is. It's been used here several times and people > >>>> understood the meaning. > >>> > >>> Sorry, that doesn't make it a word. Lots of people understand pwnd and > >>> any manner of language specific to a small group. That doesn't make it > >>> a part of any language. > >>> > >>> -- > >>> > >>> Rick > >> > >> Usage of words define them. Dictionaries just reflect the most common > >> and established usage. > >> > >> Glorbfutz is a word. So is snurglefop. If they're not words, what > >> are they? Gibberish consists of words, they're just not very useful. > > > >Ok, by your definition everything is a word. End of discussion. > > Way to miss the point. > > I agree with this guy: > > http://stancarey.wordpress.com/2010/07/12/not-a-word-is-not-an-argument/ > > > Eric Jacobsen > Anchor Hill Communications > http://www.anchorhill.com
I propose the following scientific approach to resolving the word issue. 1. Agree on a definition of the term word. 2. From the agreed upon definition, derive a set of criteria for which something may be judged a word. 3. Test a candidate word against the criteria. 4. Reject the candidate if it fails to satisfy the criteria. 5. Else accept the candidate as a word. Hope this helps. Lito
>On Sat, 10 Jan 2015 03:24:37 -0600, "kaz" <37480@dsprelated> wrote: > >>>Rick Lyons <R.Lyons@_bogus_ieee.org> wrote: >>> >>>(snip) >>> >>>> [1] I vote that you use "spectra" instead of "spectrums." >>> >>>It might be that some plurals aren't used much, but spectra is >>>pretty common. (At least in the spectroscopy world.) >>> >>>> [2] I suggest you go through your material and change >>>> all instances of the word "frame" to the >>>> word "sample." Why use the non-standard, and >>>> possibly confusing, word "frame" for a single number >>>> when the rest of the world of DSP literature uses >>>> the word "sample" to describe a single number? >>> >>>> [3] I suggest you go through your figures (like >>>> Figure 2.6 for example) and show all discrete >>>> sequences (discrete signals) as a series of dots >>>> rather than as continuous curves. Imagine how confused >>>> a DSP beginner will be when they see a picture of a >>>> continuous (analog) signal and you call it a "sampled >>>> signal" or a "sampled waveform." This is a big deal. >>>> For the sake of your readers, please do not ignore >>>> this suggestion. >>> >>>Without having actually looked, I might say that a continuous >>>curve with dots at sample points could work, but I agree with >>>Rick, you can't just have the curve. (Unless the sample points >>>are so close that you can't resolve the dots.) >>> >>>-- glen >>> >> >>I see continuous or discrete curve irrelevant. > >Are you saying that graphically depicting a >discrete sequence with what looks like a continuous >curve is acceptable? >
yes of course, that is what you realized as well. The plot function moves linearly from one level to next. That is 1st order interpolator and makes it look like continuous. Yes all digital values are discrete and so it can'y be displayed otherwise.
>>All matlab plots (and
>>possibly other tools) produce default continuous curve. e.g. freqz(h,1) > >You're joking, right. All of Matlab's plotting >capabilities consist of plotting straight lines >from one discrete amplitude value to another discrete >amplitude value. Zoom in on your freqz(h,1) plot >and you'll see what I mean. >
> >By the way kaz, check out Matlab's 'stem(x)' command. > >[-Rick-] >
or plot with dots. I prefer dots with linear interpolation to see signal trend, If you zoom in on freqz you will realize that the amplitude levels (steps) disappear, possibly a false graphics effect to start with. But it shouldn't matter as all I want is see response. Kaz _____________________________ Posted through www.DSPRelated.com
On Mon, 05 Jan 2015 12:20:43 -0600, "AllenDowney" <103119@dsprelated>
wrote:

>I am developing a textbook for a computational (as opposed to mathematical) >approach to DSP, with emphasis on applications (as opposed to theory). > >I have a draft of the first 8 chapters, working on two more. I am >publishing excepts and the supporting IPython notebooks in my blog, here: > >http://thinkdsp.blogspot.com/2015/01/january-is-dsp-month.html > >Of if you want to go straight to the book, it is here: > >http://think-dsp.com > >Comments (and corrections) are welcome!
Hello Allen, I liked the material in your Sections 7.1 and 7.2. [-Rick-]
On 2015-01-08 16:14, Eric Jacobsen wrote:
[...]
>> All I know is virii ain't a word in any language. > > Apparently it is. It's been used here several times and people > understood the meaning.
Very likely, using "viruses" or "viria" will be understood too. So, we have a situation where a word either does not have plural, or it has at least 3. This seems inconsistent. So, either we do not know, or there is not rule, at least in English, on how to handle it. BTW, my spell checker accepts "viruses", but it rejects "virii" and "viria". bye, -- piergiorgio