little math puzzle. Map 1 0 1 to 1 0.5 0

05212018, 10:24 AM
(This post was last modified: 05212018 10:25 AM by pier4r.)
Post: #1




little math puzzle. Map 1 0 1 to 1 0.5 0
Similar to "which kind of programmer are you": http://holyjoe.net/hp/flash07.txt
(there the e^x solution was quite neat) One get in input a value that can be 1 or 0 or 1 . The objective is to map those input to: 1 > 1 0 > 0.5 1 > 0 Of course, the first approach is a "switch case" block. Other ideas? (note that the first range is scaled to the second, but one ending point stays the same) Wikis are great, Contribute :) 

05212018, 11:24 AM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 02:33 PM
Post: #3




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 10:24 AM)pier4r Wrote: Of course, the first approach is a "switch case" block. Other ideas? (note that the first range is scaled to the second, but one ending point stays the same) The Xs are in arithmetic progression with d=1 while the Ys have d=0.5 so Y=X/2 plus a constant. As Y(0)=0.5 the constant is precisely 0.5 and so Y=X/2+0.5 which of course is the same solution as Thomas'. The L.R. (Linear Regression) function on most any HP calc new or old would give you the solution at once (slope and intercept). Regards. V. . Find All My HPrelated Materials here: Valentin Albillo's HP Collection 

05212018, 04:31 PM
(This post was last modified: 05212018 04:47 PM by Dieter.)
Post: #4




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 10:24 AM)pier4r Wrote: One get in input a value that can be 1 or 0 or 1 . That's trivial since changing the input by 1 changes the output by 0,5. So (11), (00,5) and (–10) are points on a straight line with a slope of 0,5. Due to (00,5) the yintercept is 0,5 as well. So you can get the parameters by simply looking at the data. ;) Instead of 0,5x + 0,5 you can also write (x+1)/2. Or in RPN: 1 + 2 / WP34s users can save a step with INC X #1/2 x BTW, you may vary the puzzle with a nonlinear mapping. For three points it can always be done with a parabolic fit. But maybe there also is another and shorter/faster way to do it. ;) What about 5 > 2 2 > 1 1 > 0 As a kind of warmup you may try 1 > 1 0 > 0 –1 > 0 ;) Dieter 

05212018, 05:06 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 05:20 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 05:34 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
<0ɸ0> Joe 

05212018, 06:13 PM
(This post was last modified: 05212018 06:18 PM by Dieter.)
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 06:28 PM
(This post was last modified: 05212018 06:32 PM by Werner.)
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
1>1
0>0 1>0 Mine: X<0? CLX Cheers, Werner 

05212018, 06:34 PM
(This post was last modified: 05212018 06:52 PM by Dieter.)
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 07:06 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
2 bytes if in FIX 00 mode
LN RND 

05212018, 07:26 PM
(This post was last modified: 05212018 07:30 PM by Dieter.)
Post: #12




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 07:06 PM)Logan Wrote: 2 bytes if in FIX 00 mode Great. But for a complete solution you'd have to add a FIX 0, and this makes it one of the possible 3 step solutions. But on an HP67 it's even 4 steps, or 4 bytes on the '41. However, logs usually are a bit slow, and changing the display mode should be avoided, if possible. But it can be done with the same 3 steps without logs and without a special display setting. Dieter 

05212018, 07:28 PM
Post: #13




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 06:13 PM)Dieter Wrote:(05212018 05:34 PM)Joe Horn Wrote: 1  NOT Ah yes, models differ. 1 – NOT works in all RPL models. <0ɸ0> Joe 

05212018, 07:33 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 06:34 PM)Dieter Wrote: And now for the trickier part: 1 – SQRT Works on all RPN/RPL models, I think. <0ɸ0> Joe 

05212018, 07:46 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 07:53 PM
Post: #16




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 04:31 PM)Dieter Wrote: That's trivial since changing the input by 1 changes the output by 0,5. So (11), (00,5) and (–10) are points on a straight line with a slope of 0,5. Due to (00,5) the yintercept is 0,5 as well. So you can get the parameters by simply looking at the data. ;) True. I thought about scaling a range. Wikis are great, Contribute :) 

05212018, 07:56 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
What about
sqrt ip Arno 

05212018, 07:57 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0  
05212018, 07:58 PM
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RE: little math puzzle. Map 1 0 1 to 1 0.5 0
ups
Arno 

05212018, 08:07 PM
Post: #20




RE: little math puzzle. Map 1 0 1 to 1 0.5 0
(05212018 06:34 PM)Dieter Wrote: And now for the trickier part: (05212018 07:46 PM)Dieter Wrote:(05212018 07:33 PM)Joe Horn Wrote: 1 – SQRT 2 / INT JF :) 

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