- [OT] USA solar eclipse Aug.21.2017 - 8 Updates
- Gay marriage (was Re: Available C++ Libraries FAQ) - 1 Update
- reading random bytes from memory - 4 Updates
- What can love do? - 5 Updates
- abort core dump message into a user file as log message - 5 Updates
- quaternion graphics in C or C-style C++? - 2 Updates
| Mr Flibble <flibbleREMOVETHISBIT@i42.co.uk>: Aug 23 12:41AM +0100 On 22/08/2017 21:37, Rick C. Hodgin wrote: > to you as though they are truth), will be your undoing, Leigh. > It is not God who will condemn you. You will condemn you, > because you would not hear the truth. Everything you say is predicated on your belief that the Bible is true. Well consider this: Assumption #1: Genesis creation story is a myth/allegory and Adam and Eve are a fiction. Assumption #2: Jesus Christ (either biblical or historical) existed. The Bible (Old and New Testaments) describe the genealogy of Jesus Christ all the way from Joseph and Mary back to Adam and Eve. Given our two assumptions at what point does this 50-generation genealogy transition from fact to fiction and what is the proof of this transition? IMO the entire genealogy is suspect and assumption #2 is bogus. There is no evidence contemporary to Christ's existence of his existence: it all came out in the latter part of the first century in writings from the likes of Josephus and Tacitus a significant time after Jesus's supposed death. The Gospels themselves are complete hearsay which wouldn't hold water as evidence in a court of law. If you now claim that assumption #1 is false despite all the evidence to the contrary (e.g. weathering of the Grand Canyon, fossils confirming evolution and evolutionary time scales) then you really are beyond help as nothing can be done to mitigate such obtuse stupidity. [snip] /Flibble |
| "Öö Tiib" <ootiib@hot.ee>: Aug 22 11:04PM -0700 On Wednesday, 23 August 2017 02:42:00 UTC+3, Mr Flibble wrote: > Everything you say is predicated on your belief that the Bible is true. Yes, so it is. Why you drag it out again? Conclusions reached not using rational logic but something else (like dreams, faith, desires, fears, doubts and/or dislikes) can't be argued with rational logic. Try to give some harmless spider to arachnophobe. Whatever you tell how good and cute and even intelligent the spider is and how it eats annoying insects and never bites you ... it does not matter. Aracnophobe is fully convinced that death is near and that you are holding the spider in you bare hand is some sorcery and no way an evidence of its harmlessness. |
| David Brown <david.brown@hesbynett.no>: Aug 23 09:15AM +0200 On 22/08/17 22:23, Mr Flibble wrote: > you stop posting religious shite I am not interested in your > non-religious posts including those about C++. > /Flibble Look, he wrote a pleasant post about an amazing real-world experience - watching the eclipse. I have seen one myself, here in Norway, and the sight is awe-inspiring. It does not matter if you are a dedicated religious believer marvelling at God's creation, an atheist marvelling at the beauty of nature, or anything else - if you are human, you will marvel at a full solar eclipse. The post was off-topic in all the groups posted, but it was a friendly post that does no harm. Even the religious content was negligible. Your ugly, crude, angry and repetitive provocations are /not/ welcome. They are not helpful, they are not enjoyable, they are not informative, they are not intelligent, logical or rational. They do nothing but provoke Rick to post more religious waffle, which nobody wants. They spoil every thread they touch. So please take your own advice, and stick to C++. |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 05:11AM -0400 On 8/22/2017 7:41 PM, Mr Flibble wrote: >> It is not God who will condemn you. You will condemn you, >> because you would not hear the truth. > Everything you say is predicated on your belief that the Bible is true. Everything I believe is predicated on Jesus Christ being who He says He is, and a portion of who He is is recorded in the Bible. The experience every Christian has personally is that our faith does not resting solely upon the words of Bible, but upon the application of the One described in the Bible given to us in our daily lives. I came to faith because I read in the Bible the truth about God, about sin, about me, about Jesus Christ, but there is more to God than His written word. There is the full application of His presence in our daily lives, and it is there, from withing that relationship He initiates with us and that we enjoy each day, that the reality of His existence in our lives is manifest. We don't hover over a book as our soul source, but we learn over time that the Bible aligns with God's spirit, and God's spirit aligns with the Bible, and that there is also another spirit at work in this world that aligns not with God's spirit or the teachings of the Bible. It is that anti-Christ spirit, the exact opposite of Christ, the one who is leading souls to their destruction, the one who is causing wars and spreading hate and inflicting disease. He is the one Christ defeated at the cross, and it is why today we (mankind) has victory over sin. ----- The message of salvation is given to all of mankind, Leigh. Everyone can be saved by believing in Jesus Christ and asking Him to forgive their sin. But not everybody will be saved. Many will hear the message, reject it, believe it to be that which is false, and never accept His offer of salvation, and will enter into Hellfire for all eternity because of it. God does not force Himself on people. He calls out to every soul and says, "Here am I. With everything I possess I stand before you saying, 'Come, and I will give you eternal life.'" He calls out to every soul in one way or another, but only those who answer His call will be saved. ----- If you can hear His call in your heart, in your inmost core, in the depths of your soul, from that place where you know that you are hearing Him, the still small voice inside when you are at peace, in silence with nothing distracting you, but then in the stillness, when you are seeking the truth and being completely honest with yourself ... if you can hear His call within, then rejoice because it is Him reaching out to save your eternal soul from judgment, to give you new life, to restore you to His eternal Kingdom of love, peace, power, and authority. The message of the cross is given to all who will be saved. It is not intended for other people. He doesn't want to judge us, but He will honor our request. We will either call upon Him to be our Savior, or call upon Him to be our judge. The choice is ours, for He has already done every- thing necessary on both sides. He created Hell to contain all falseness, and He gave us His Son Jesus Christ to make a way out of judgment for just the asking. It's your choice, Leigh. You wanted the power to choose your own fate? Jesus gives you that choice. Make it a good one. Thank you, Rick C. Hodgin |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 05:35AM -0400 On 8/23/2017 4:44 AM, Rod Pemberton wrote: > Also, don't look > at God because you'll die by doing so. (Exodus 33:20) Or, is KJV > implying that God murders you for staring at him? ... Hard to tell. It's because God is Holy, Holy, Holy, and we are fallen in sin. No flesh can look upon God and live because the purity of His holiness would induce judgment and condemnation upon the sin that lives in us. We would be consumed in an instant. Because we are born in sin, raised in sin, live in sin, know the things of this world (which are all in and of sin), we think we have some kind of handle on the state of reality, and that it falls within the realm of that which we know. What the cross teaches us is that there is more, and that we do not yet know the truth, nor do we have that which we need on our own. The cross teaches us that there is more, and that all who will look to the cross will discover this, because God Himself will lead all who do so to the truth Himself, so that it is not distorted, not twisted in some way, but for all who will truly seek the truth, God will ensure personally that they find it. The truth is it's only when Christ takes our sin away that we are able to then stand before God again, and look upon Him, and even then not until we leave this world and receive our new bodies: https://www.biblegateway.com/passage/?search=1+Corinthians+15%3A53-55&version=KJV It's not difficult to understand and know the truth about God. It just requires an honest, truth-seeking heart. There are many teachers around who will give you correct information. There are not many students who are interested in hearing the lessons of Jesus Christ because they are too focused on the sin they enjoy in their life to ever look up, step away, and learn it. > Isn't it an interesting coincidence that the Sun and KJV God are so > similar? Didn't the Egyptians worship the sun God Ra? ... They are not similar. There is only one God, though there are many gods: https://www.biblegateway.com/passage/?search=1+Corinthians+8&version=KJV 5 For though there be that are called gods, whether in heaven or in earth, (as there be gods many, and lords many,) 6 But to us there is but one God, the Father, of whom are all things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by him. We also are God's children. Scripture refers to us as gods: https://www.biblegateway.com/passage/?search=John+10%3A34-38&version=KJV 34 Jesus answered them, Is it not written in your law, I said, Ye are gods? This future, this restoration to our true state, the one sin fully denies of us here in this world, that is what the enemy of God is trying to keep us from. He wants us to remain in our sin-induced ignorance, to believe this world we live in, these minds we possess, this existence is all there is. He wants us to stay away from God, stay away from the truth, stay away from salvation, so that he can defeat us in his rebellion against God. He wants us dead in his battle, not just here in sin on the Earth, but in eternity in judgment. But Jesus has made a way out from that for all who will hear. He's made a way to restore us to His Kingdom of love, power, and eternity. ----- God calls out to you, Rod, and to all people. He doesn't do it as part of a cocktail joke or a punchline. He doesn't do it as by the mocking of ignorant souls who say that such a call is only for fools and weak people. He calls out to His creation in strength, in honor, in a restoration of all right things. He does so to give us that which we cannot attain on our own. He does so to give us a second chance, to overcome death, Hell, and the grave. He does so to restore us to His Kingdom, and bring us back despite our many runnings in all manner of other directions, toward other interests, pushing Him away, kicking at Him like a spoiled child, demanding that He leave us alone. Despite all of this, He remains faithful to us, a good Father, a good God. There was a skit written and performed at Winterfest in Knoxville Tennessee in 2006 that outlines this path. It shows God creating everything, sharing all He has with man, and then sin enters in. Temptations away from God enter in through those evil spirits which tempt men away from God toward other things. We see the downfall of man, the despair from the separation, the confusion. But we then see how God steps in to overcome and defeat that which we could not defeat ourselves. It's such a brilliant skit. I literally have watched it more than 50 times over the years and cannot watch it without crying when I see what God did to restore us. He loves us so much that despite our mass and personal rebellions against Him, yet did He make a way out for all who would yet believe and repent of their sinful ways: https://www.youtube.com/watch?v=cyheJ480LYA ----- Eternity and eternal life are given to mankind. It comes to us through that which Jesus Christ did on the cross. He made a way out of our sin. He literally saved us from death. Thank you, Rick C. Hodgin |
| gazelle@shell.xmission.com (Kenny McCormack): Aug 23 10:25AM In article <onj9qm$9uc$1@dont-email.me>, David Brown <david.brown@hesbynett.no> wrote: ... >Look, he wrote a pleasant post about an amazing real-world experience - (etc - no need to repost) Heh heh. Here we have a CLC reg actually defending the undefendable - namely, the egregious Ricky-from-Indiana nutcase. It's the Trump effect. People (and I use the term loosly here) like Trump and Ricky just keep hammering away with their nonsense - bringing down the level of discourse so that we come to accept whatever they do as (almost) normal. We (and by "we", I mean us as CLC readers/posters and, in the larger sense, the US media) end up looking desperately for something to praise - something that's not quite as awful as the rest of it. And thus every time the Orange One fails to poop his pants on national TV, the media starts gushing about how "Presidential" he is. And whenever Rick manages to post something here that isn't completely stupid, we all want, instinctively, to say "Well done, sir!". It is human nature to want to find something to praise - something that validates the BS we were all taught growing up watching Sesame Street - the idea that there is good in everyone. -- The book "1984" used to be a cautionary tale; Now it is a "how-to" manual. |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 08:10AM -0400 On 8/23/2017 6:25 AM, Kenny McCormack wrote: > It is human nature to want to find something to praise... It is a natural part of us from within, because God put that natural draw within us. What He teaches us though is that there is the voice of truth, and the voice of falseness. The voice of truth only speaks with one voice, but the voice of falseness has an array to choose from. We know this from our natural thinking: "How old are you?" If you're like my 13-year old son and a 15-year old were to answer "15," he'd say, "No you're not. You're not exactly 15. You're 15 and some number of months, days, hours..." But all things being equal if you're 15 there's one correct answer: 15. To answer 14, or 16, or 12, or 20 ... they are all false answers. The truth speaks with one voice always. It only speaks of itself, and it is always triumphant over every falsehood when things are pressed into and examined. The truth is the foundation God used to construct His entire universe, and nothing false or embracing falseness will survive this world. ----- God's promise to us is this: Seek the truth and you will find it. That's His promise because He is truth, and He knows all who are His own by volition, by seeking, by the right He gives them to pursue Him in seeking the truth. It's also why you've never found it, Kenny. You're not looking for it. You're trying to defend your pre-existing belief against the truth, trying to force the things that be into the moulds you've constructed. You, like many many others, have preformed moulds that you're sure are right. Anything that is therefore also right must fit into those moulds. You are unwilling to consider the idea that your moulds are your own construction, and they're not truly right. You are unwilling to put down your moulds and go and look into other things and see where the real truth is, even the one that doesn't look like a shape your moulds would produce. If you ever put down that mould set, and then begin that journey ... on that very day you will find it, because all it requires is the tiniest inkling of a real pursuit of truth, and then it is found because the truth comes running for you, and He prepares you for the banquet feast made in your honor: https://www.biblegateway.com/passage/?search=Luke+15%3A20-24 ----- Kenny, God loves you. He wants you to be a part of His eternal Kingdom in the paradise of Heaven. It's why He went through all He did on Earth, and why He endures all the ridicule and scorn today, and why He calls on us who already believe to endure the same types of ridicule and scorn for His name ... because the soul that is saved is most valuable, precious and dear in His sight. It's why He came to the Earth as a suffering Savior ... to literally save that which was lost. To save sinners like you and me. Thank you, Rick C. Hodgin |
| Ivan Shmakov <ivan@siamics.net>: Aug 23 03:40PM ... Heard on a Russian TV channel, in the conclusion of a news report regarding the (then-forthcoming) event: In Russia, the eclipse can be observed in Chukotka, Alaska, and some of the Arctic Ocean islands. Left me quite wondering... -- FSF associate member #7257 58F8 0F47 53F5 2EB2 F6A5 8916 3013 B6A0 230E 334A |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 11:08AM -0400 On 8/17/2017 3:34 PM, Rick C. Hodgin wrote: > It never is okay to be gay as it goes against everything God > has established in His creation here for the understanding of > man on the Earth. I came across this today and found it interesting. It gives the definition of marriage in Noah Webster's first American dictionary from 1828, and indicates the type of marriage that was intended by God, taught by God, and the apostles in the New Testament. It is the form that would've existed before the 20th century: http://webstersdictionary1828.com/Dictionary/marriage MAR'RIAGE, noun [Latin mas, maris.] The act of uniting a man and woman for life; wedlock; the legal union of a man and woman for life. marriage is a contract both civil and religious, by which the parties engage to live together in mutual affection and fidelity, till death shall separate them. marriage was instituted by God himself for the purpose of preventing the promiscuous intercourse of the sexes, for promoting domestic felicity, and for securing the maintenance and education of children. Marriage is honorable in all and the bed undefiled. Hebrews 13:4 1. A feast made on the occasion of a marriage The kingdom of heaven is like a certain king, who made a marriage for his son. Matthew 22:2. 2. In a scriptural sense, the union between Christ and his church by the covenant of grace. Revelation 19:7. This last portion, "the union between Christ and his church" is the whole crux of the matter. God has given us an Earthly pattern of the future marriage of the church (believers) and Christ in eternity. We will be married to God, and Him to us, and what He has will be ours, and what we have will be His, just as in Earthly marriages today when the possessions of both spouses become community property. That wasn't setup for no reason. It has a Biblical foundation, and was the guidance God gave us as a proper course for young people as they go through life: to marry, leave their mothe and father, and then raise their own family. It is God's natural plan for mankind, and it is the pattern we have to understand how the close, personal relationship between us and God will be in eternity. As spouses know so much more than other people about their spouse, so we will be intimate with God in that close relational way. ----- Some others: http://webstersdictionary1828.com/NoahWebster http://webstersdictionary1828.com/Dictionary/sin http://webstersdictionary1828.com/Dictionary/faith http://webstersdictionary1828.com/Dictionary/prayer http://webstersdictionary1828.com/Dictionary/education We see the effect of a decline in education today in our world- wide societies, and especially so in America where even our presidents have abandoned God and brought forth abhorrent ideas in His sight. Noah Webster wrote in the definition: "...To give children a good education in manners, arts and science, is important; to give them a religious education is indispensable; and an immense responsibility rests on parents and guardians who neglect these duties." There is a punishment for parents who do not teach their children correctly before God. Children are naturally trusting. They are born with their trust turned on. And when we teach them things, they take them at face value. The teachings of the children learned by the teaching (or lack of teaching) by the parents is conveyed unto their children. The Bible takes a very dim view on those who cause one of God's little ones to stumble, as all children will start out believing in God if you teach them. It is written to their inner core, but the sin nature of this world can take that away. It's why we find: https://www.biblegateway.com/passage/?search=Proverbs+22%3A6&version=KJV 6 Train up a child in the way he should go: and when he is old, he will not depart from it. God wants us to raise up God-fearing children, so they are serving Him in this world, loving people, helping people, doing good, not doing wrong. It's not a form of control mechanism invented by man or the state, though some men have usurped its existence and used it for that purpose. The true root is from God, as God wants His creation doing right and teaching one another aptly. Thank you, Rick C. Hodgin |
| Juha Nieminen <nospam@thanks.invalid>: Aug 23 05:18AM > That's probably true of the systems that fir will meet, and it's > certainly true of anything bigger than a mobile 'phone. I doubt you'll find a mobile phone for which you can write your own software which doesn't use hardward and an OS supporting (and using) memory protection and mapping. > It's _not_ correct for some of the smaller embedded processors and the > RTOSes that run on them - there are quite a lot of low end CPUs out > there still running in real address mode with no protection. Sure, there are very simple embedded systems out there, and sometimes you can even write software for them in C++, but from the average user's perspective they are quite a rarity. They may be really common in certain industries, but not amont the average programmer. |
| David Brown <david.brown@hesbynett.no>: Aug 23 09:04AM +0200 On 23/08/17 07:18, Juha Nieminen wrote: > you can even write software for them in C++, but from the average user's > perspective they are quite a rarity. They may be really common in certain > industries, but not amont the average programmer. Microcontrollers with linear memory (i.e., no virtual memory) totally dominate the processor world, and vastly outnumber the devices with virtual memory. Some of these will have memory protection units, which can limit the access to parts of memory, but most do not have them (or do not use them). After all, when your system only has one program, there is no need for protection from other processes. Many of these are programmed in C++, which has been used on small embedded microcontrollers for decades, and has become more popular as devices like small ARM microcontrollers have got cheaper and more dominant. Still, they are mostly programmed in C rather than C++. |
| scott@slp53.sl.home (Scott Lurndal): Aug 23 12:29PM >Microcontrollers with linear memory (i.e., no virtual memory) totally >dominate the processor world, and vastly outnumber the devices with >virtual memory. While that's likely true - there are, after all, still 6502's being sold - one must consider that the actual number of programmers who program those microcontrollers is so small it's in the noise when contrasted with the programmers coding for more sophisticated processors. |
| David Brown <david.brown@hesbynett.no>: Aug 23 04:57PM +0200 On 23/08/17 14:29, Scott Lurndal wrote: > who program those microcontrollers is so small it's in the noise > when contrasted with the programmers coding for more sophisticated > processors. That is a different matter, of course. But as more "mainstream" programmers use different languages, and more people use hobby embedded systems, I think that embedded programming is a quite a significant proportion of C (not C++) programming. It is extremely difficult to get any serious statistics on this sort of thing, and my guesses could be way out. |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 08:19AM -0400 Jesus is love -- https://www.biblegateway.com/passage/?search=1%20John+4%3A10 Jesus came to the Earth to set us free from judgment. Because of this, He is the way, truth, and the life -- https://www.biblegateway.com/passage/?search=John+14:6 ----- Love saves a sinful man from judgment before God. Love takes a wretched man and transforms him into a servant of God. Love take a sinful past and brings it forth as a witness unto others of the saving grace in Christ, and that the transformation is real. ----- Love is patient. Love is kind. Love does not envy. Love does not boast. Love is not [excessively] proud. Love does not dishonor others. Love is not self-seeking. Love is not easily angered. Love keeps no record of wrongs. Love does not delight in evil. Love rejoices in truth. Love always protects. Love always trusts. Love always hopes. Love always perseveres. Love never fails. https://www.biblegateway.com/passage/?search=1+Corinthians+13%3A4-8&version=NIV ----- Love can do all things ... and did all things for us at the cross. Love has a name. Love's name is Jesus Christ. Thank you, Rick C. Hodgin PS - Consider these words I write to you. Ponder them in your heart. |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:27AM -0700 On Wednesday, August 23, 2017 at 5:50:17 PM UTC+5:30, Rick C. Hodgin wrote: > Thank you, > Rick C. Hodgin > PS - Consider these words I write to you. Ponder them in your heart. sorry my friend its more than enough u know :) |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:28AM -0700 On Wednesday, August 23, 2017 at 5:50:17 PM UTC+5:30, Rick C. Hodgin wrote: > Thank you, > Rick C. Hodgin > PS - Consider these words I write to you. Ponder them in your heart. I dont believe in these words really |
| "Rick C. Hodgin" <rick.c.hodgin@gmail.com>: Aug 23 08:34AM -0400 On 8/23/2017 8:28 AM, kushal bhattacharya wrote: >> Rick C. Hodgin >> PS - Consider these words I write to you. Ponder them in your heart. > I dont believe in these words really We are powerful creations. When we move, it is for real, be it toward falseness, or toward truth. God has given us the true power and authority to make our own choices. In those choices, God asks us to put Him to the test. He says to try Him, to test Him and see, to prove Him out. He makes claims that if we will put our faith and trust in Him we can see Him working in our lives in ways we can truly understand. You can test these words out and see by asking God to prove to you in a way you can understand. You must be willing to receive it when the proof comes, by the way. You can't just parrot the words, "Okay God ... Rick said to ask You this, so I'm asking. Looking for that proof he says You'll bring. So, whenever You're ready." If you want to test Him out, approach Him like this: "God, I honestly don't know if you're real or not. But if you are real, if Jesus did die for my sins to save me, I want to know the truth. I don't want lies, and I don't want to guess. I want to know." If you can approach Him in that way, He'll give you the proof you require in a way you'll be able to uniquely identify. Thank you, Rick C. Hodgin |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:39AM -0700 On Wednesday, August 23, 2017 at 6:05:11 PM UTC+5:30, Rick C. Hodgin wrote: > you require in a way you'll be able to uniquely identify. > Thank you, > Rick C. Hodgin I am sorry its my fault here |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 04:55AM -0700 Hi, Is it possible in Linux,that I can dump the abort message to my own named file when the program crashes? Thanks |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:31AM -0700 On Wednesday, August 23, 2017 at 5:25:50 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is it possible in Linux,that I can dump the abort message to my own named file when the program crashes? > Thanks I am developing a user program which will ge notified about the crash and the crash stacktrace would be shown to him |
| scott@slp53.sl.home (Scott Lurndal): Aug 23 12:33PM >Hi, >Is it possible in Linux,that I can dump the abort message to my own named file when the program crashes? >Thanks What "abort message" are you referring to? When an Operting System handles an uncaught signal that has default termination semantics (e.g. SIGSEGV), it will terminate the process. The process status is passed to the parent process (generally a shell) via the waitpid(2), waitid(2) or wait(2) system calls. The parent process is free to handle this in any fashion. Most shells will print a message to stderr. |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:37AM -0700 On Wednesday, August 23, 2017 at 6:03:12 PM UTC+5:30, Scott Lurndal wrote: > (generally a shell) via the waitpid(2), waitid(2) or wait(2) > system calls. The parent process is free to handle this in > any fashion. Most shells will print a message to stderr. Suppose if the program aborts with a message like Terminate called with active exception ,i want to dump this message into a file.I want to do this because the user program is runing as a daemon so no message would be printed on the terminal and the user wont be notified normally in this case |
| kushal bhattacharya <bhattacharya.kushal4@gmail.com>: Aug 23 05:38AM -0700 On Wednesday, August 23, 2017 at 6:03:12 PM UTC+5:30, Scott Lurndal wrote: > (generally a shell) via the waitpid(2), waitid(2) or wait(2) > system calls. The parent process is free to handle this in > any fashion. Most shells will print a message to stderr. In this case the parent process is not notified at all so how would i handle this situation |
| David Melik <dchmelik@gmail.com>: Aug 23 02:57AM -0700 (reply below is on Usenet and 'blind carbon copy' (BCC) to a listserv) On 08/21/2017 05:12 AM, SG wrote: > rotation matrix. Given a normalized quaternion q, it's rather easy to > determine a corresponding rotation matrix R > R = q2rot(q) (I won't bother defining q2rot) Not define... why? If, for example, quaternions (or anything) were being described in a pure mathematics textbook, *everything* would be defined, probably full detail (unless left as an exercise, where at least they'd define their terms.) It turns out I won't necessarily need definition now (if you see my reply to your question below,) but... > convert the quaternion back to a 3x3 rotation matrix because this > matrix representation is more efficient for such things in terms of > number of necessary floating point operations. Ok, so apparently they don't really improve something as basic as rotating a cube. So, if I made a larger or generalized 3D system, they could be useful. For the cube I did, I combined my rotation matrices for the three angles myself, beforehand. So, it seems, I won't achieve anything more by replacing that. > I think that answers your question? Part of it (and all most important parts for now.) I still want to learn quaternions for a 3D C or C-style C++ program, and now have a better overview (not details)... but you've clarified, I should try a 3D thing they're more useful for, first, or just a calculation program. So, I'll have to choose which way to continue, before any more detailed questions. That's all for now on on Usenet from me. ------------------------------------------------------------------------ Note to listserv I sent this to (after recent discussion.) Double-check any reply you write won't also have Usenet newsgroups in 'To:,' unless desired (probably will only be 'To:' me, but I forgot how it works when you post to a listserv & Usenet both.) My original post (only small part quoted above) was to Usenet news://comp.graphics.algorithms , news://comp.lang.c , news://comp.lang.c++ newsgroups. |
| Richard Damon <Richard@Damon-Family.org>: Aug 23 07:56AM -0400 On 8/23/17 5:57 AM, David Melik wrote: > defined, probably full detail (unless left as an exercise, where at > least they'd define their terms.) It turns out I won't necessarily need > definition now (if you see my reply to your question below,) but... I think he meant that he wasn't going to write out the code for q2rot(). Quaternions are well defined mathematically, and the creation of q2rot() is a mostly mechanical process of looking at the definition and putting it to code. > For the cube I did, I combined my rotation matrices for the three angles > myself, beforehand. So, it seems, I won't achieve anything more by > replacing that. Quaternions provide a compact notation for representing an orientation, and a fairly simple way to chain rotations. For actually doing the rotations to lots of objects, the simple rotation matrix can be simpler/faster (so converting the Quaternion to a matrix near the end makes sense). One other factor is computational stability, chaining Quaternions can't mess up the scale of orthogonality of the axes, while with a rotation matrix, the round off errors in each operation can gradually build up to cause these sorts of errors, |
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