Weird Units Conversion
09-03-2019, 12:36 AM
Post: #1
 MattGreer Member Posts: 58 Joined: Aug 2019
Weird Units Conversion
If I convert 1_Mft to 1_ft, I get (added commas for clarity) 1,000,000_ft

If I convert 1_Mft^3 to 1_ft^3, I get 1.E18_ft3.

What's going on?

I'm trying to set something up to convert 1 MMscfd to 1 scfm. So "one million standard cubic feet per day" to "standard cubic feet per minute". Volumetric flow. I can do this by hand easy of course but I like mucking with the calculator.

What am I missing?

Thanks!

-Matt
09-03-2019, 02:21 AM
Post: #2
 Thomas Okken Senior Member Posts: 1,810 Joined: Feb 2014
RE: Weird Units Conversion
The prefix applies to the base unit. So, for example, a cubic centimeter a.k.a. cc, or cm^3, is [one centimeter] cubed or one millionth of a cubic meter, and not one centi-[cubic meter].
09-03-2019, 02:46 AM
Post: #3
 MattGreer Member Posts: 58 Joined: Aug 2019
RE: Weird Units Conversion
I see!

So how would I go about creating a custom unit "Million Cubic Feet"? I've not tried that before...

Thanks!

-Matt
09-03-2019, 03:34 AM (This post was last modified: 09-03-2019 03:35 AM by Thomas Okken.)
Post: #4
 Thomas Okken Senior Member Posts: 1,810 Joined: Feb 2014
RE: Weird Units Conversion
It's highly unconventional, but hft^3 appears to work, "cubic hectofoot."
09-03-2019, 05:38 AM (This post was last modified: 09-03-2019 01:45 PM by Giuseppe Donnini.)
Post: #5
 Giuseppe Donnini Member Posts: 124 Joined: Feb 2014
RE: Weird Units Conversion

1. 1000000_ft^3 'Mcbf' STO
(Store the unit object 1000000_ft^3 into the variable Mcbf or whatever name you want to assign to your new unit).

(Add any units you want to the list. Note that it is not sufficient to put the name of the unit into the list, you must use a full unit object, e.g. if you want to add ft^3, put 1_ft^3 into the list).

This produces a menu key for your new unit with the same functionality as a built-in unit menu key, i.e.:

[Mcbf]  multiplies by the new unit;
LS+[Mcbf]  converts to the new unit;
RS+[Mcbf]  divides by the new unit.

Try  5000000_ft^3 LS+[Mcbf], and you will get the expected result of  5_Mcbf.

Note that this new unit is a simple, non-compound unit which may itself be prefixed with any SI prefix.
09-03-2019, 05:55 AM
Post: #6
 MattGreer Member Posts: 58 Joined: Aug 2019
RE: Weird Units Conversion
You guys are amazing. Thank you!

Thanks!

-Matt
09-09-2019, 05:05 AM
Post: #7
 MattGreer Member Posts: 58 Joined: Aug 2019
RE: Weird Units Conversion
Giuseppe,

I'm considering upgrading to either a 50G or a Prime. My limited understanding of the Prime is that it's very different when it comes to storing variables and especially with units conversions.

What you described above, can that be done with the Prime? One thing I've definitely taken advantage of with the 48GX is the CST menu with many combinations of custom units. I'm hoping I can do the same with the Prime, but I'm hearing that's not very possible?

Thanks!

-Matt
09-09-2019, 04:57 PM
Post: #8
 Marco Polo Member Posts: 223 Joined: Jun 2016
RE: Weird Units Conversion
(09-09-2019 05:05 AM)MattGreer Wrote:  Giuseppe,

I'm considering upgrading to either a 50G or a Prime. My limited understanding of the Prime is that it's very different when it comes to storing variables and especially with units conversions.

What you described above, can that be done with the Prime? One thing I've definitely taken advantage of with the 48GX is the CST menu with many combinations of custom units. I'm hoping I can do the same with the Prime, but I'm hearing that's not very possible?

AFAIK no. That's why I still use a 50g and don't plan to switch to Prime.
09-10-2019, 10:30 PM (This post was last modified: 09-10-2019 10:35 PM by Claudio L..)
Post: #9
 Claudio L. Senior Member Posts: 1,843 Joined: Dec 2013
RE: Weird Units Conversion
(09-09-2019 04:57 PM)Marco Polo Wrote:
(09-09-2019 05:05 AM)MattGreer Wrote:  Giuseppe,

I'm considering upgrading to either a 50G or a Prime. My limited understanding of the Prime is that it's very different when it comes to storing variables and especially with units conversions.

What you described above, can that be done with the Prime? One thing I've definitely taken advantage of with the 48GX is the CST menu with many combinations of custom units. I'm hoping I can do the same with the Prime, but I'm hearing that's not very possible?

AFAIK no. That's why I still use a 50g and don't plan to switch to Prime.

I agree. If custom units is your thing, you can't beat the 50g... until you install newRPL of course
EDIT: Back up that wink with a link.
09-11-2019, 01:49 AM
Post: #10
 MattGreer Member Posts: 58 Joined: Aug 2019
RE: Weird Units Conversion
(09-10-2019 10:30 PM)Claudio L. Wrote:
(09-09-2019 04:57 PM)Marco Polo Wrote:  AFAIK no. That's why I still use a 50g and don't plan to switch to Prime.

I agree. If custom units is your thing, you can't beat the 50g... until you install newRPL of course
EDIT: Back up that wink with a link.

I'm confused, are you saying you can't beat the 50g, until you have a 50g?

Thanks!

-Matt
09-11-2019, 05:18 AM
Post: #11
 Giuseppe Donnini Member Posts: 124 Joined: Feb 2014
RE: Weird Units Conversion
I totally agree. This is one of the many reasons why the HP Prime has absolutely no appeal to me.

However, it is only fair to mention that Didier Lachièze developed a program for the HP Prime, called Units48, which tries to mimick the HP-48 unit management.

See here: https://www.hpcalc.org/details/8911
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