Frank Raffaeli wrote:
"Kevin Aylward" wrote in message ... [snipped much voluminous banter] Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. [snipped more banter] Does the above pose a question, or is it mere rhetoric? Could the scientific method be applied with gusto? Are Win and Kev evenly matched? I don't know. How tall is he, I'm only 5'8" Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
Frank Raffaeli wrote:
"Kevin Aylward" wrote in message ... [snipped much voluminous banter] Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. [snipped more banter] Does the above pose a question, or is it mere rhetoric? Could the scientific method be applied with gusto? Are Win and Kev evenly matched? I don't know. How tall is he, I'm only 5'8" Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
Kevin Aylward wrote:
Terry Given wrote: herewith a self-confessed doesnt-know-it-all's analysis: IF y(x) = mx+c (even KA cant argue with the linearity (and time-invariance) of this....LOL) THEN y(ax) = max+c AND ay(x) = max+ac The more I look at this, the more I realise that I am over the heads of you guys. I am making standard assumptions, and because some individuals are simple not conversant with common knowledge in the field, make what are, basically Jesus wept statements. For starters, there is obviously confusion here on sufficiency and necessesity. If a function satisfies a(f(x)) = f(ax) is it guaranteed to be linear? Now, we are discussing practical modulators/amplifiers. Do we care about dc offsets? For those knowledgeable in the field, do we usually need to actually specify that dc offsets are being ignored in normal explanations? for instance, do we usually use a capacitor to eliminate them? I must apologise for this. I need to be more aware that many are not aware of common assumptions, that are taken as read, by those individuals, who, for example, have been doing analogue design, for example, for 20+ years. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
Kevin Aylward wrote:
Terry Given wrote: herewith a self-confessed doesnt-know-it-all's analysis: IF y(x) = mx+c (even KA cant argue with the linearity (and time-invariance) of this....LOL) THEN y(ax) = max+c AND ay(x) = max+ac The more I look at this, the more I realise that I am over the heads of you guys. I am making standard assumptions, and because some individuals are simple not conversant with common knowledge in the field, make what are, basically Jesus wept statements. For starters, there is obviously confusion here on sufficiency and necessesity. If a function satisfies a(f(x)) = f(ax) is it guaranteed to be linear? Now, we are discussing practical modulators/amplifiers. Do we care about dc offsets? For those knowledgeable in the field, do we usually need to actually specify that dc offsets are being ignored in normal explanations? for instance, do we usually use a capacitor to eliminate them? I must apologise for this. I need to be more aware that many are not aware of common assumptions, that are taken as read, by those individuals, who, for example, have been doing analogue design, for example, for 20+ years. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
Kevin Aylward wrote: gwhite wrote: "Eric C. Weaver" wrote: This discussion happens all the time on comp.dsp, between primarily computer-science folks approaching DSP and EE types approaching it. EE folks' definition of "linear" implicitly includes time invariance; Interesting thought since a Signals and Systems course, or a Linear Systems course, or a Communications course is often required to get an EE degree. After all, these courses explicitly distinguish the linearity property and the time-invariance property. And I've never seen the "af(t) = f(at)" so-called "definition" until a few days ago. Your a liar. LOL. Its that simple. I clearly stated that it was *not* a definition. "Linearity can more easily be expressed as: a(f(t)) = f(at)" -- Kevin Aylward I think someone is posting under your name. A nasty bit of business that is. It was simply trying to illustrate the concept of constant gain. You expanding on some trivial minor point to avoid answering the main issue, to wit, you have failed to disprove my claim on your class A amplifier. Class A works just fine in multipliers/modulators -- "non-linearity" of circuit elements is not required. Maybe you can analyze the old MC1496. That would be enlightening to you. But more important and more simple (it will save you loads of time), just apply *the* linearity test for h(t) x(t) - y(t). The notion that y=x^2 is a non-linear equation is universally accepted by anyone who has done even the slightest bit of theory on basic algebraic equations. It does not require any qualification in the slightest. No ****, by why are you rambling on and on about it? Show me one, and I mean just one, that declares y=x^2 a linear equation. That is clever -- you want me to "declare" something is true that I've made no reference to. You are quite the inventor. Face it: you had an incorrect notion about linearity. All the rest of your words are twisting, squirming, and turning to try to save face after you acted condescending (and still do) about a very simple matter. That's all. |
Kevin Aylward wrote: gwhite wrote: "Eric C. Weaver" wrote: This discussion happens all the time on comp.dsp, between primarily computer-science folks approaching DSP and EE types approaching it. EE folks' definition of "linear" implicitly includes time invariance; Interesting thought since a Signals and Systems course, or a Linear Systems course, or a Communications course is often required to get an EE degree. After all, these courses explicitly distinguish the linearity property and the time-invariance property. And I've never seen the "af(t) = f(at)" so-called "definition" until a few days ago. Your a liar. LOL. Its that simple. I clearly stated that it was *not* a definition. "Linearity can more easily be expressed as: a(f(t)) = f(at)" -- Kevin Aylward I think someone is posting under your name. A nasty bit of business that is. It was simply trying to illustrate the concept of constant gain. You expanding on some trivial minor point to avoid answering the main issue, to wit, you have failed to disprove my claim on your class A amplifier. Class A works just fine in multipliers/modulators -- "non-linearity" of circuit elements is not required. Maybe you can analyze the old MC1496. That would be enlightening to you. But more important and more simple (it will save you loads of time), just apply *the* linearity test for h(t) x(t) - y(t). The notion that y=x^2 is a non-linear equation is universally accepted by anyone who has done even the slightest bit of theory on basic algebraic equations. It does not require any qualification in the slightest. No ****, by why are you rambling on and on about it? Show me one, and I mean just one, that declares y=x^2 a linear equation. That is clever -- you want me to "declare" something is true that I've made no reference to. You are quite the inventor. Face it: you had an incorrect notion about linearity. All the rest of your words are twisting, squirming, and turning to try to save face after you acted condescending (and still do) about a very simple matter. That's all. |
Kevin Aylward wrote: It is that simple. Nope. Its not. Linearity has many definitions. It doesn't have "many definitions" when it comes to the EE profession. The one definition is wholly consistant across academic texts -- without known contradiction. Everyone who took courses like Circuits, Fields and Waves, and on and on, also took a Signals and Systems (or similar under a different name) course. That some, such as you for example, didn't learn or understand the definition is notwithstanding. Look, I have no problem with your example of a particular definition of linearity. I already explained how such an example is meaningless in analogue design by giving an example. A mathematical definition only has meaning if it is useful when it is applied. In analogue design this definition is useless, so it is not used. It is useful to the extent modulation is a linear operation produced by devices such as gilbert cells biased to Class-A. It is very useful definition: for example, high data rate modern digital communications systems routinely utilize linear modulation/demodulation. It doesn't even matter if the upper transistors in the gilbert cells are driven to the switch mode (switch mode is not a requirement; class-A will do) by the LO. It is still linear modulation. This system is linear: The System +---------------+ | | in | /¯¯¯\ | out x(t) O--------( X )---------O y(t) | \___/ | | | | | | | | O | | cos(w_c·t) | +---------------+ This one is not: The System +---------------------+ | | in | /¯¯¯\ /¯¯¯\ | out x(t) O--------( X )--( + )-------O y(t) | \___/ \___/ | | | | | | +--------+ | | | | | O | | cos(w_c·t) | +---------------------+ Do you know why? Hint: it has nothing to do with any "exp(x)" or other solid state issues. You nor anyone else need take my word for it: it is in *all* the Signals, Systems, and Communications texts I've ever opened up -- they are wholly consistant with each other; check for yourself. I don't care a toss about and communication texts. Sheesh -- no ****! I care about linearity as understood in the solution of the non-linear differential equations used in Spice. Like I said early on: you can make the answer come out however you want if you are permitted to make up the rules and change them as you play. Look, I don't claim that the particular definition of linearity that you presence is "wrong" in principle. It is a very well known definition. However, it is one of many, and is simple not applicable in this context. It is the definition for the EE profession. I clearly said that linearity, as defined in analogue design, is essentially defined by the absence of any frequencies in the output not present in the input. That "definition" is incorrect, as has been pointed out already. You were off on a roll trying to impress people which mathematical technicalities that are simple irrelevant in the context of this original discussion. Right. I was trying to "impress" by using a couple of trig identities. LOL I know all about your definition. I dont disagree that it is a valid definition in some contexts. It is the definition for the EE context. If you want an LTI system, then so be it. However, it is not applicable to electronic circuit design that is based on the solution of non-linear differential equations, with the "non-linear" term having a universally accepted meaning by the 10,000s of mathematician who actually study such equations. It is not a matter of a mathematician's characterization of equations. It is the EE characterization, and this is largely an EE forum. If you are a mathematician and not an EE, then I can see why you would believe what you do. You arnt wrong in this thread because of you particular claim of linearity. It isn't "my claim." It is the standard definition for EE's. That some EE's didn't quite "get it" is notwithstanding. The real reason for this disagreement is that you are talking apples and I am talking fish net stockings. You are applying the term linearity in a completely different sense than the one I am using. Both are valid in principle, and are indeed well accepted, under their appropriate conditions. Your definition is not the EE definition. That is y=f(x) is non-linear as defined in any math text book you care to name. This is a matter of EE definition. Recall how you sniped about the EE courses I apparently didn't take "with all due respect." "A linear system, cannot produce frequencies that are not in the input, essentially, by definition. With all due respect, I would guess you don't have an EE B.S. degree. This is all pretty basic stuff really." -- Kevin Aylward So you originally sniped about my education in electrical engineering, and then ignore those very same basics taught in all EE curriculums, and then turn course and take refuge in a math text. Okay, Kevin, have it your way. |
Kevin Aylward wrote: It is that simple. Nope. Its not. Linearity has many definitions. It doesn't have "many definitions" when it comes to the EE profession. The one definition is wholly consistant across academic texts -- without known contradiction. Everyone who took courses like Circuits, Fields and Waves, and on and on, also took a Signals and Systems (or similar under a different name) course. That some, such as you for example, didn't learn or understand the definition is notwithstanding. Look, I have no problem with your example of a particular definition of linearity. I already explained how such an example is meaningless in analogue design by giving an example. A mathematical definition only has meaning if it is useful when it is applied. In analogue design this definition is useless, so it is not used. It is useful to the extent modulation is a linear operation produced by devices such as gilbert cells biased to Class-A. It is very useful definition: for example, high data rate modern digital communications systems routinely utilize linear modulation/demodulation. It doesn't even matter if the upper transistors in the gilbert cells are driven to the switch mode (switch mode is not a requirement; class-A will do) by the LO. It is still linear modulation. This system is linear: The System +---------------+ | | in | /¯¯¯\ | out x(t) O--------( X )---------O y(t) | \___/ | | | | | | | | O | | cos(w_c·t) | +---------------+ This one is not: The System +---------------------+ | | in | /¯¯¯\ /¯¯¯\ | out x(t) O--------( X )--( + )-------O y(t) | \___/ \___/ | | | | | | +--------+ | | | | | O | | cos(w_c·t) | +---------------------+ Do you know why? Hint: it has nothing to do with any "exp(x)" or other solid state issues. You nor anyone else need take my word for it: it is in *all* the Signals, Systems, and Communications texts I've ever opened up -- they are wholly consistant with each other; check for yourself. I don't care a toss about and communication texts. Sheesh -- no ****! I care about linearity as understood in the solution of the non-linear differential equations used in Spice. Like I said early on: you can make the answer come out however you want if you are permitted to make up the rules and change them as you play. Look, I don't claim that the particular definition of linearity that you presence is "wrong" in principle. It is a very well known definition. However, it is one of many, and is simple not applicable in this context. It is the definition for the EE profession. I clearly said that linearity, as defined in analogue design, is essentially defined by the absence of any frequencies in the output not present in the input. That "definition" is incorrect, as has been pointed out already. You were off on a roll trying to impress people which mathematical technicalities that are simple irrelevant in the context of this original discussion. Right. I was trying to "impress" by using a couple of trig identities. LOL I know all about your definition. I dont disagree that it is a valid definition in some contexts. It is the definition for the EE context. If you want an LTI system, then so be it. However, it is not applicable to electronic circuit design that is based on the solution of non-linear differential equations, with the "non-linear" term having a universally accepted meaning by the 10,000s of mathematician who actually study such equations. It is not a matter of a mathematician's characterization of equations. It is the EE characterization, and this is largely an EE forum. If you are a mathematician and not an EE, then I can see why you would believe what you do. You arnt wrong in this thread because of you particular claim of linearity. It isn't "my claim." It is the standard definition for EE's. That some EE's didn't quite "get it" is notwithstanding. The real reason for this disagreement is that you are talking apples and I am talking fish net stockings. You are applying the term linearity in a completely different sense than the one I am using. Both are valid in principle, and are indeed well accepted, under their appropriate conditions. Your definition is not the EE definition. That is y=f(x) is non-linear as defined in any math text book you care to name. This is a matter of EE definition. Recall how you sniped about the EE courses I apparently didn't take "with all due respect." "A linear system, cannot produce frequencies that are not in the input, essentially, by definition. With all due respect, I would guess you don't have an EE B.S. degree. This is all pretty basic stuff really." -- Kevin Aylward So you originally sniped about my education in electrical engineering, and then ignore those very same basics taught in all EE curriculums, and then turn course and take refuge in a math text. Okay, Kevin, have it your way. |
On Sun, 7 Sep 2003 18:52:46 +0100, "Kevin Aylward"
wrote: Paul Burridge wrote: On Sun, 7 Sep 2003 16:12:29 +0100, "Kevin Aylward" wrote: Oh, so you didn't understand it properly then? No, I understood it perfectly. It was probably some political dogma that he threw in at that moment that did it. I recall thoroughly enjoying 'the Ragged Trousered Philanthropists' up until the point where Tressel stated that there was something unnatural about mature men remaining unmarried. You've lost me here. Its a been a while since I read the selfish gene, but there is no way Dawkins would hold to such a silly idea. I'm not suggesting he held *this* particular loony idea. The example from Tressel was only that; an example. No he didn't. Of course, people tighten up or refine their original Must have been. However, as I said minor changes in position are not important, one cant get all the details right first time. Indeed. Hence the re-think between the books. They were what? 10 years apart? People move on and refine their ideas. You should read Wittgenstein to see how far a man can change his outlook over the course of his life! I remember when I did not understand the details well enough to apply the theory to picking up women. A naive approach would be to do things for the women's direct interest, i.e. maybe the women could survive better, and pass on her genes better that way, i.e acting on the assumption that a women would chose if you were "nice" to her. Boy was I wrong. A women will do what ever maximises the number of her genes. I think you've phrased that rather poorly but I believe I know what you mean. This results in one main fact. She chooses a mate, essentially, only on the basis of good gene stock. She doesn't want a nice person because this would mean her offspring would also be nice, and thereby do things not in there own best interest. She wants a "mean" offspring. That is, treat them mean, keeps them keen The theories great. It explains quite nicely why women chose those yobbys that beat them up. Can't agree there. Women are basically genetically obliged to pick the best mate they can get their hands on, given the limitations imposed by their own pulling abilities. What they are looking for in every case is a mate who can give their offspring the best chance of survival and 'thrival' in this wide, mean world. Interestingly enough, the qualities the male must display to succeed change according to different ages (historical ages, not biological) and cultures. At varying times, men have been favoured because of, for example, they're exceptionally good fighters. Or unusually good hunters... later in history, we see female preferences based on wealth and status. But in countries where for idealogical reasons, all people are 'made to be equal' like the old Soviet Union or the 'old' China, females must pick according to other criteria such as a gift for literature, music or art. They're all programmed to do their best for the unborn child, even if they don't want children at all or are too old to conceive. No, you conclude wrong. There was nothing, or little really new. So, "The Blind Watchmaker" by its very title tells you that it is explaining the details of how apparently consciously designed intricate objects, are not designed, but just a result of random process. This is a trivial deduction to the theory of replicators. In addition, it is well recognised that it was the selfish gene book that really made the **** hit the fan. I genuinely got bored with the book. boggle! I don't agree. Reviews mean f'all. Have you actually read all the "review" on the later editions of Hawking's "Brief history of time". It make you want to vomit. Sure, his a very clever dude, but he is ceratyinly not a god. I didn't say he was. In fact he admitted to wasting much time working on 'singularities' with Roger Penrose donkey's years ago. As noted above, it was the selfish gene that revolutionised the approach to evolution as to the body being a mere vehicle for the masters, the genes and memes. Let's just put it down to a matter of personal preference, then. [not particularly relevant Einstein example snipped] The whole emphases on Darwin is wrong, it is a legacy theory. The fundamental idea is the Replicator, as such, a "handicap" is just a specific detail of how some particular Replicators can replicate better. I'm not sure what you're driving at here but I don't like the sound of it. Rubbish. You demonstrably know sweet FA about global economics as demonstrated in our recent exchanges on the subject where you cut and run like a scalded cat when faced with cogent arguments from someone (me) with indisputable expertise in the area. Nonsense. It was just something that I could not be bothered to debate. I have little interest in economics, other than how much I get paid, which concerns me greatly. LOL! Yeah, whatever. You quit while you were behind. You should have quit earlier but I think you just about backed out before you sustained any terminal damage. :-) If your claiming that Dawkins retracted the basics of Replicators, then your dreaming. I'll have to see what Miller is specifically addressing. I'm suggesting no such thing. I'm simply saying that Dawkins softened his line of selfishness a good measure from the position you wrongly (now) attribute to him. I have read a few bits and bobs from creationists who claim that Dawkins recanted on his evolutionary views. It was all crap, as he himself explained. Yes I know. The attempts were laughable. Well, obviously, you could not refute my argument that selfishness is inherent. As I said, its a tautology. It can't be contradicted. Okay, well let's put you this question: if everyone is basically selfish, why do some people help other people out on newsgroups? I think I know what your answer will be but I want to see it from you yourself in black and white. And don't be afraid this time, Kev. Evolution's not my specialist area. :-) -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
On Sun, 7 Sep 2003 18:52:46 +0100, "Kevin Aylward"
wrote: Paul Burridge wrote: On Sun, 7 Sep 2003 16:12:29 +0100, "Kevin Aylward" wrote: Oh, so you didn't understand it properly then? No, I understood it perfectly. It was probably some political dogma that he threw in at that moment that did it. I recall thoroughly enjoying 'the Ragged Trousered Philanthropists' up until the point where Tressel stated that there was something unnatural about mature men remaining unmarried. You've lost me here. Its a been a while since I read the selfish gene, but there is no way Dawkins would hold to such a silly idea. I'm not suggesting he held *this* particular loony idea. The example from Tressel was only that; an example. No he didn't. Of course, people tighten up or refine their original Must have been. However, as I said minor changes in position are not important, one cant get all the details right first time. Indeed. Hence the re-think between the books. They were what? 10 years apart? People move on and refine their ideas. You should read Wittgenstein to see how far a man can change his outlook over the course of his life! I remember when I did not understand the details well enough to apply the theory to picking up women. A naive approach would be to do things for the women's direct interest, i.e. maybe the women could survive better, and pass on her genes better that way, i.e acting on the assumption that a women would chose if you were "nice" to her. Boy was I wrong. A women will do what ever maximises the number of her genes. I think you've phrased that rather poorly but I believe I know what you mean. This results in one main fact. She chooses a mate, essentially, only on the basis of good gene stock. She doesn't want a nice person because this would mean her offspring would also be nice, and thereby do things not in there own best interest. She wants a "mean" offspring. That is, treat them mean, keeps them keen The theories great. It explains quite nicely why women chose those yobbys that beat them up. Can't agree there. Women are basically genetically obliged to pick the best mate they can get their hands on, given the limitations imposed by their own pulling abilities. What they are looking for in every case is a mate who can give their offspring the best chance of survival and 'thrival' in this wide, mean world. Interestingly enough, the qualities the male must display to succeed change according to different ages (historical ages, not biological) and cultures. At varying times, men have been favoured because of, for example, they're exceptionally good fighters. Or unusually good hunters... later in history, we see female preferences based on wealth and status. But in countries where for idealogical reasons, all people are 'made to be equal' like the old Soviet Union or the 'old' China, females must pick according to other criteria such as a gift for literature, music or art. They're all programmed to do their best for the unborn child, even if they don't want children at all or are too old to conceive. No, you conclude wrong. There was nothing, or little really new. So, "The Blind Watchmaker" by its very title tells you that it is explaining the details of how apparently consciously designed intricate objects, are not designed, but just a result of random process. This is a trivial deduction to the theory of replicators. In addition, it is well recognised that it was the selfish gene book that really made the **** hit the fan. I genuinely got bored with the book. boggle! I don't agree. Reviews mean f'all. Have you actually read all the "review" on the later editions of Hawking's "Brief history of time". It make you want to vomit. Sure, his a very clever dude, but he is ceratyinly not a god. I didn't say he was. In fact he admitted to wasting much time working on 'singularities' with Roger Penrose donkey's years ago. As noted above, it was the selfish gene that revolutionised the approach to evolution as to the body being a mere vehicle for the masters, the genes and memes. Let's just put it down to a matter of personal preference, then. [not particularly relevant Einstein example snipped] The whole emphases on Darwin is wrong, it is a legacy theory. The fundamental idea is the Replicator, as such, a "handicap" is just a specific detail of how some particular Replicators can replicate better. I'm not sure what you're driving at here but I don't like the sound of it. Rubbish. You demonstrably know sweet FA about global economics as demonstrated in our recent exchanges on the subject where you cut and run like a scalded cat when faced with cogent arguments from someone (me) with indisputable expertise in the area. Nonsense. It was just something that I could not be bothered to debate. I have little interest in economics, other than how much I get paid, which concerns me greatly. LOL! Yeah, whatever. You quit while you were behind. You should have quit earlier but I think you just about backed out before you sustained any terminal damage. :-) If your claiming that Dawkins retracted the basics of Replicators, then your dreaming. I'll have to see what Miller is specifically addressing. I'm suggesting no such thing. I'm simply saying that Dawkins softened his line of selfishness a good measure from the position you wrongly (now) attribute to him. I have read a few bits and bobs from creationists who claim that Dawkins recanted on his evolutionary views. It was all crap, as he himself explained. Yes I know. The attempts were laughable. Well, obviously, you could not refute my argument that selfishness is inherent. As I said, its a tautology. It can't be contradicted. Okay, well let's put you this question: if everyone is basically selfish, why do some people help other people out on newsgroups? I think I know what your answer will be but I want to see it from you yourself in black and white. And don't be afraid this time, Kev. Evolution's not my specialist area. :-) -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
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