How to enter whole degrees and decimal minutes ?

[springer5]

Hi

Does anyone know of a way to enter whole degrees and decimal minutes on the HP Prime?


For example, to calculate....

12 degrees and 35.67 minutes plus 24 degrees and 18.553 minutes.


I'm trying to use my Prime for marine navigational formulae and all the data is presented in this format. the degrees,minutes,seconds button on the Prime only accepts whole numbers of each.

I can of course convert it all to decimal degrees but that's a pain when the formulae are quite complex and each new set of numbers needing to be entered is based on the previous step's results. It means I'm converting in the middle of formula entry which is very cumbersome and prone to error.


Anyone know of a way?


Thanks in advance

[CyberAngel]

(04-06-2020 01:25 PM)springer5 Wrote:  Hi

Does anyone know of a way to enter whole degrees and decimal minutes on the HP Prime?


For example, to calculate....

12 degrees and 35.67 minutes plus 24 degrees and 18.553 minutes.


I'm trying to use my Prime for marine navigational formulae and all the data is presented in this format. the degrees,minutes,seconds button on the Prime only accepts whole numbers of each.

I can of course convert it all to decimal degrees but that's a pain when the formulae are quite complex and each new set of numbers needing to be entered is based on the previous step's results. It means I'm converting in the middle of formula entry which is very cumbersome and prone to error.


Anyone know of a way?


Thanks in advance

You need to make your own input routine = code a program
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VPN

[springer5]

(04-06-2020 02:21 PM)CyberAngel Wrote:  You need to make your own input routine = code a program
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VPN

Thanks CyberAngel.

I wrote a simple program to add or subtract sets of numbers in that format, but when it comes to long, complex formulas all with different structures it gets very complicated.
Some formulas might have 3 arguments, some 10, so the input routines would either have to be written for each permutation or a routine setup at the beginning which asks the user to specify structure prior to input and the program would almost have to write itself each time depending on the work at hand.

One day sin-1 (C * sin(lat)+ S * cos (lat)

Maybe on another day z1 =z1/tan(dec)

On a third day both of them together.

and so on. All the above variables requiring to be input in whole degrees and decimal minutes *as the formulas is worked through* because some of the variables themselves have to be looked up in tables (or not) depending on the previous calculation.

It really needs to be done manually.

Too much for the Prime I'm thinking now.

Jus the simple firmware routine to allow input of decimal minutes when using the degrees, minutes and seconds button would have made it so easy.

I'd hoped it might be simpler than that using "the great HP Prime" but so be it.

Thanks for clarifying that there's no built in way to do it though.

Cheers

[Nigel (UK)]

Try this.

• Press "Define" (blue-shift "x t theta n" key). This lets you define a function with arguments.
• Name your function DM (decimal minutes) (for example).
• Enter A + B/60 for the function definition.
• Press ok as appropriate.
  

Now, whenever you enter DM(7,16.5) it will evaluate to 7.275. At any point in a calculation, if you want to enter degrees and decimal minutes, just type DM with the appropriate arguments and (if the calculator is in degrees mode) it will all work.

Nigel (UK)

[springer5]

(04-06-2020 04:23 PM)Nigel (UK) Wrote:  Try this.

• Press "Define" (blue-shift "x t theta n" key). This lets you define a function with arguments.
• Name your function DM (decimal minutes) (for example).
• Enter A + B/60 for the function definition.
• Press ok as appropriate.
  

Now, whenever you enter DM(7,16.5) it will evaluate to 7.275. At any point in a calculation, if you want to enter degrees and decimal minutes, just type DM with the appropriate arguments and (if the calculator is in degrees mode) it will all work.

Nigel (UK)

Awesome! Thanks Nigel.

This looks like a good solution for what I need.

I haven't used the Define feature before so I wasn't famiiliar with it. But it looks like it's just what I need.

Thanks again. I appreciate it. You've just saved me from a massive headache

[Nigel (UK)]

I'm glad to have helped. My pleasure!

Nigel (UK)

[ijabbott]

This is probably a can of worms, but it would be nice if the Prime at least accepted DDM (degrees decimal minutes) format on input, even if it then automatically converted it to DMS, which doesn't sound too hard to do. Displaying the results in DDM format would be a whole separate can of worms though!

(For what it's worth, Casio scientific calculators allow input in DD, DDM or DMS format, but can only display results in DD or DMS format.)

[Tim Wessman]

Yeah, it probably could accept without too much trouble.... Maybe will look at that sometime. Display is a no go as we have no more flags on the real number object unfortunately.

[CyberAngel]

(04-07-2020 08:24 AM)Tim Wessman Wrote:  Yeah, it probably could accept without too much trouble.... Maybe will look at that sometime. Display is a no go as we have no more flags on the real number object unfortunately.

How many different Real Number formats do you use?
Do they each have a separate flag for simplicity?
Maybe some flags could be reused by priotizing the selection to other formats & hours/degrees formats?
Perhaps you already did that and totally ran out of flags. < Sigh > < muttering "what do I know” >
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[zeb]

Apologies for asking this ; I do not want to press you. But is this feature (accepting decimal numbers within the DMS format) still planned? This is very useful for navigation/astronomical purposes, and this is a very common feature supported by most calculators these days (Casio have it since the 80s). Thanks a lot in advance.

[pinkman]

(04-06-2020 04:23 PM)Nigel (UK) Wrote:  Try this.

• Press "Define" (blue-shift "x t theta n" key). This lets you define a function with arguments.
• Name your function DM (decimal minutes) (for example).
• Enter A + B/60 for the function definition.
• Press ok as appropriate.
  

Now, whenever you enter DM(7,16.5) it will evaluate to 7.275. At any point in a calculation, if you want to enter degrees and decimal minutes, just type DM with the appropriate arguments and (if the calculator is in degrees mode) it will all work.

Nigel (UK)

As an alternative I suggest to define DM like this:

→HMS(IP(X)+(FP(X)*5/3))

Usage: DM(7.165) returns 7°16′30″

[Albert Chan]

(04-06-2020 01:25 PM)springer5 Wrote:  12 degrees and 35.67 minutes plus 24 degrees and 18.553 minutes.

How about adding unit for minute and seconds ?

XCas> M := 1./60; S := M/60
XCas> 12+35.67M + 24+18.553M       → 36.9037166667

[Stefan_Titan2944A]

Given the "restriction" that you use HOME mode and RPN entry:

12 degrees and 35.67 minutes plus 24 degrees and 18.553 minutes.

12°35.67 ENTER
60 / +
24° 18.553 ENTER
60 / +
+

36°54'13.38"

BR
Stefan