topic Re: Projectile motion in LabVIEW
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194994#M1214051
<BLOCKQUOTE><HR /><LI-USER login="Bob_Schor" uid="95728"></LI-USER> wrote:<BR />
<P>Bill,</P>
<P> </P>
<P> "Complex" just isn't "Real", it is also "Imaginary" (at the same time ...). Still, it does make for a "simpler" (in some mathematical sense) mapping of a 2-Dimensional space than do "real" numbers (which take Two to Tango ...).</P>
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<P>Bob Schor</P>
<HR /></BLOCKQUOTE>
<P>There are many cases where using complex numbers simplifies the math.</P>
<P>In circuit analysis, Ohm's law doesn't work for AC, if you use real numbers. But if you use complex voltage, complex current, and complex impedance, then Ohm's law does work and you can do circuit analysis without trig.</P>Tue, 30 Nov 2021 18:18:02 GMTpaul_cardinale2021-11-30T18:18:02ZProjectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193205#M1213304
<P>I am trying to create the simulation of a projectile motion in Labview. Here is vi I am using. The formula for y I am using is this :<FONT face="arial black,avant garde"> <SPAN>y = (tan θ</SPAN><SUB>0</SUB><SPAN>)x – gx</SPAN><SUP>2</SUP><SPAN>/2(v0cosθ<SUB>0</SUB>)</SPAN><SUP>2 </SUP></FONT></P>
<P>I am using case structure to allow negative values of angles to exist too. I read here in community that for negative angles the formula needs to have + instead of - . Parabola comes out okay for almost every angle, however for 30 degree it comes out like this: </P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="kimcheese_1-1637415172316.png" style="width: 400px;"><img src="https://forums.ni.com/t5/image/serverpage/image-id/295051i4B643D274A09A7C5/image-size/medium?v=v2&px=400" role="button" title="kimcheese_1-1637415172316.png" alt="kimcheese_1-1637415172316.png" /></span></P>
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<P>I suspect it is because x*tan(alpha) is smaller than the second part of the formula, therefore negative values come out. 60 degrees and 45 are okay. How can I get a simulation for 30 degrees?</P>Sat, 20 Nov 2021 13:32:06 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193205#M1213304kimcheese2021-11-20T13:32:06ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193224#M1213314
<P>First of all, note that the trigonometric functions want radians (full circle is 2pi, not 360), so a value of "30" corresponds to quite a few turns. Make sure to convert it first!</P>
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<P>It would be so much simpler to calculate the evolution of x and y independently (each initialized according to angle and magnitude). Now the speed in x is constant and the speed in y is a simple acceleration. (you can even add a air friction term later if needed). No tan needed.</P>
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<P>Even easier, do things using complex numbers!</P>
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<P> </P>Sat, 20 Nov 2021 17:51:44 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193224#M1213314altenbach2021-11-20T17:51:44ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193232#M1213319
<P>It seems ironic to me that "simpler" is "complex".</P>Sat, 20 Nov 2021 20:06:11 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193232#M1213319billko2021-11-20T20:06:11ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193234#M1213321
<P>Bill,</P>
<P> </P>
<P> "Complex" just isn't "Real", it is also "Imaginary" (at the same time ...). Still, it does make for a "simpler" (in some mathematical sense) mapping of a 2-Dimensional space than do "real" numbers (which take Two to Tango ...).</P>
<P> </P>
<P>Bob Schor</P>Sat, 20 Nov 2021 20:16:47 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4193234#M1213321Bob_Schor2021-11-20T20:16:47ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194054#M1213635
<P>I just read my previous response to my wife, and told her it had 4 Kudos. She said I should say "If you like this response, don't thank me, thank <EM>i</EM> ". But that would just be silly ...</P>
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<P>Bob Schor</P>Thu, 25 Nov 2021 03:21:42 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194054#M1213635Bob_Schor2021-11-25T03:21:42ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194065#M1213638
<P>4 kudos is just under-rated, these puns are worth being made historic so that someone in the future can quote it as "by Bob Schor"</P>Thu, 25 Nov 2021 05:33:46 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194065#M1213638santo_132021-11-25T05:33:46ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194953#M1214041
<P>that was fun</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="projectile.png" style="width: 999px;"><img src="https://forums.ni.com/t5/image/serverpage/image-id/295428iEEA2F19B78F08197/image-size/large?v=v2&px=999" role="button" title="projectile.png" alt="projectile.png" /></span></P>
<P> </P>Tue, 30 Nov 2021 16:04:11 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194953#M1214041alexderjuengere2021-11-30T16:04:11ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194994#M1214051
<BLOCKQUOTE><HR /><LI-USER login="Bob_Schor" uid="95728"></LI-USER> wrote:<BR />
<P>Bill,</P>
<P> </P>
<P> "Complex" just isn't "Real", it is also "Imaginary" (at the same time ...). Still, it does make for a "simpler" (in some mathematical sense) mapping of a 2-Dimensional space than do "real" numbers (which take Two to Tango ...).</P>
<P> </P>
<P>Bob Schor</P>
<HR /></BLOCKQUOTE>
<P>There are many cases where using complex numbers simplifies the math.</P>
<P>In circuit analysis, Ohm's law doesn't work for AC, if you use real numbers. But if you use complex voltage, complex current, and complex impedance, then Ohm's law does work and you can do circuit analysis without trig.</P>Tue, 30 Nov 2021 18:18:02 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4194994#M1214051paul_cardinale2021-11-30T18:18:02ZRe: Projectile motion
https://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4196214#M1214519
<BLOCKQUOTE><HR /><LI-USER login="paul_cardinale" uid="260910"></LI-USER> wrote:<BR />There are many cases where using complex numbers simplifies the math.
<P> </P>
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<P>Here's my quick attempt using complex only (no explicit trigonometry!). I am sure it can be polished up a bit. <span class="lia-unicode-emoji" title=":grinning_face_with_smiling_eyes:">😄</span></P>
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<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="altenbach_1-1638732250535.png" style="width: 999px;"><img src="https://forums.ni.com/t5/image/serverpage/image-id/295643i3F0A50ADDD2D6E3B/image-size/large?v=v2&px=999" role="button" title="altenbach_1-1638732250535.png" alt="altenbach_1-1638732250535.png" /></span></P>
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<P> </P>Sun, 05 Dec 2021 19:24:25 GMThttps://forums.ni.com/t5/LabVIEW/Projectile-motion/m-p/4196214#M1214519altenbach2021-12-05T19:24:25Z