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### L. R. , What is L R ? I was asked that one day. He was not ready for the answer.

One Day, On the tailgate of my survey truck I had plans waiting to be look at , and calculators here and there with Data Collectors, scales ,triangles erasers pen , pencils the every day survey items. this day was no different . But wait it was, sewer on one street a storm sewer on the next and  grade had to be set on a drainage ditch. It was one of those jobs that was taken so soon ,like here are the plans ,he has  equipment waiting on YOU. In my day and time this was no big deal I wasn't brought in the day of Auto Cadd  so this wasn't no dog and pony show to me. I had seen this movie many times. Now I had a new I Man that thought he was smarter than the average bear , then what comes out of he mouth  as he picks up my HP 32s calculator, which he had never seen before. What does this key do.? Of course I asked what key ? He then said the one with L R above it . My answer , everything you will do today . He said this little key. I said YEP!!

So then began his lessons on HP calculators and Linear Regression. Stay tune to here more.

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#### Replies

• Hi everyone,Here is a Grade Program I talked about above, to work with your LR function, both are very good to use. This program lets you use Rate or Percent when asked either input 0 are input percent as positive or negative .enter beginning station, R/S then beginning elevation, R/S then if you do not know the percent enter 0 R/S and program will ask for ending station R/S and ending elevation R/S and percent will be calculated then R/S will ask for station to stake. If enter percent then program will ask station to stake. I have used this program a lot.This program is my version written

by Billy Brooks for the HP 35s

HP 35s ver. GRADES LBL G

1. LBL G

2. CLx

3.CLVARS

4.SF 10

6. PSE

7. PER%+RATE

8.PSE

9. SF10

10. B = BEG STA

11.PSE

12.INPUT B

13.STO D

14. SF 10

15. E = BEG ELEV

16.PSE

17. INPUT E

18.STO Z

19. SF 10

20. IF RATE

21. PSE

22.SF 10

23. INPUT 0 (zero )

24. PSE

25. OR PER%

26.PSE

27.SF 10

28. INPUT PER%

29 PSE

30.PER +/- (+ or - )

31.PSE

32. INPUT P

33. X ╪ 0 ?

34. GTO G057

35.SF 10

36. E =ENDING STA

37.PSE

38.INPUT E

39. STO X

40. SF 10

41.E = ENDING ELEV

42.PSE

43. INPUT E

44. STO N

45. RCL N

46.RCL Z

47. ─

48.RCL X

49. RCL D

50. ─

51. ÷ ( or / )

52. 100

53. x ( times)

54. STO P

55. VIEW P

56. GTO G057

57. SF 10

58.S =STA TO SK

59. PSE

60. INPUT S

61. RCL B

62. ─

63. RCL P

64.% ( key % )

65. RCL Z

66. +

67.RCL S

68.X<>Y

69.SF 10

70. STATION

71.PSE

72. ELEVATION

73.PSE

74.R/S STOP

75.GTO G057

76.RTN

Hi Everyone , As you see regression can be programed . A simpler version is also in your Hp 35s manual on chapter 16 Statistics Programs. Manly linear regression will be use is Surveying, the
others in Engineering but also if your a student, then you may have need for this. Now i will look at how a grade program compares to linear regression function.I will use my grade program which I call Percent or Rate.It is a simple program that i will use, A given percent %, multiplies it times the
distance and this sum is then added to the beginning elev. to be equal to that station or if the percent is not known than the beginning station and the beginning elev is Entered and then the
ending station and elev is Entered it will solve the percent, then continues with the program for the
desired station.

First XEQ the program G Enter , the program will run and ask for the beginning station, We will use the above problem to compare. the beginning station is 0+00R/S then beginnin elevation =
500.00 R/S then the program will asked P? 0 for rate or Enter% .We will choose Rate, so 0.000 R/S Now the program will ask for ending Station and Elevation. First , station, 200 R/S then elev. 501.00 R/S then P= .50% . Now the program will ask station, when R/S is applied. So R/S, it will
asked station to stake, first station was 0+02 ,so 2.0 R/S=500.01 then R/S station to stake, next
0+25 , so 25, R/S = 500.125. Now since the display is two lines you will see both station at the top and elevation on the bottom line. The program works the same, if when asked for percent or rate you answer in percent then it will calculate using percent that was entered.. This program is a good
tool to have if you have a lot of grade that you calculate or even to check your plans.It will not solve
the station to elevation, but this also simple. Take the difference in the elevation that you have
increased to, we used 500.62 this means you have went up in elev. 0.62 ft from the beginning elev.
of 500.00, Now divide that by the rate per foot ,this was 0.005 per ft. 0.62/0.005 =124. so the
station of 500.62 Elev. = 1+24 The program does also take up a lot of memory in your
calculator.but this may not be a problem. The calculator as plenty of memory for other programs.If
you do not have access to a program like this, then that is when the linear regression function is a
plus .Because with it you do not need this program because linear regression is already on your
calculator.. I did not go over Inverse model or Quadratic model, but they are explained on the
https://www.educalc.net/2104083.page above, for those of you need to know them.

Billy

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• Hi Survenator,   As luck would have it, I did tell the whole story. As I was about to save it. I was correcting one last thing, I hit the space bar  and  Abracadabra !! it was all gone. So goes the life and times of a Surveyor. So I will begin again.

Billy

Billy

• Hello everyone, I would like to add this link, to this Discussion on Linear regression , what is Linear regression and what are non- linear regression models. This site I use a lot for many different things in surveying.

Billy

https://www.educalc.net/2104083.page

Mathematical Formula - Linear Regression : Educalc.net
• Linear Regression function

I guess no one seems to know... tell us!

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