Why do business calculators have log/exp but not basic trig functions?

[pier4r]

I mean, basic trig functions (cos, sin, tan) may take one key plus shifts. Why are they totally absent?

At least on the business models that I saw (the recent BA-55 thread and the 12C), there is no basic trig function. Does it cost so much to implement them? Are the trig functions totally useless in business?

What is the usage of exp/log in business computations?

[TheKaneB]

logs and antilogs are used in the TVM equation: ref. http://www.voidware.com/tvm.htm

Sine and Cosine, to the best of my knowledge are not used in any commonly occurring financial equation, so if the hardware have hard limits on memory then it's understandable that they aren't implemented.

[pier4r]

(02-19-2018 10:36 PM)TheKaneB Wrote:  logs and antilogs are used in the TVM equation: ref. http://www.voidware.com/tvm.htm

Sine and Cosine, to the best of my knowledge are not used in any commonly occurring financial equation, so if the hardware have hard limits on memory then it's understandable that they aren't implemented.

I always forget that normally y^x is done with e^(x*log(y)) therefore if they have powers they also have log/exp.

@Dave: wouldn't it be powers (and the basic 4 functions)? Only at the limit of periods (infinite) or the rate (infinitesimal) you have the exponential function. Anyway - in practice - who is going to pay for infinite time or continuous rates?

[Carsen]

I don't really know why Pier4r. As an accounting student, I haven't run across the need for trig yet. However, I would still like these functions built-in on a 12C for those special cases of me tackling some calculus on my free time and other uses.

Although we can all come to the conclusion that the 12C's functionality won't change because it continues to sell. Plus, any changes would affect it's acceptance on some exams.

[Gene]

Logs are used to solve for N in compound interest or annuity situations by "longhand" - not using the built in N button.

FV = PV (1+i)^N

N= LN(FV/PV) / LN (1+i)

Logs may also be used in regression by taking the LN of the Y values before entering the data points.


Trigs have very limited usage in business situations, true.

The REAL reason trigs should have been on every business calculator that had enough rom to put them in is to avoid having business students buy a competitor's scientific calculator to do chemistry and calculus classes and then buy a business model for accounting.

TI was VERY smart here much earlier than HP. The TI BAII Plus had trig and hyperbolics even (ha) for years and years before HP finally did it. Why? College students could buy the TI BAII Plus and have one calculator that could do everything they needed in general education / science classes and that same calculator could then do all they needed in business classes.

Someone who wanted an HP had to have two calculators. Bad idea.


Some of us complained directly to HP for years before they FINALLY (yay) came out with the HP 10BII+ machine which went above and beyond the TI BAII+ model. Great job Tim !

I think this review showed up in Datafile at the time:

HP10bII+ review



The basic competitor for the HP 10bII+ calculator is probably the Texas Instruments BAII+ calculator. The TI engineers are probably not happy with this new HP entry, since each of the functions shown below are present on the HP 10bII+ and are missing from the TI BAII+ calculator. Perhaps TI should rename their model the TI BAII– instead?

Functions on the HP 10bII+ not found on the TI BAII Plus
Entry of a number in scientific notation
Entry of a number with 12 digits
11 extra storage memories
PI
Normal distribution
Inverse Normal distribution
Student’s t distribution
Inverse Student’s t distribution
Best fit regression choice
Exponent regression model
Inverse (1/x) regression model
Weighted average
Gamma function
Markup calculations
Initial CF0 frequency other than one
No CPT (compute) key needed to solve

That is quite a list!

[Gamo]

The only missing functions on the 12C for financial matter are

1. The Pricing Calculation for Cost, Price, Markup and Margin
2. Combination and Permutation

If HP going to make the update for the 40th Anniversary maybe on the HP-12C Platinum Edition that 2 functions should be added. I hope.

Gamo

[Carsen]

(02-20-2018 01:31 AM)Gamo Wrote:  The only missing functions on the 12C for financial matter are

1. The Pricing Calculation for Cost, Price, Markup and Margin
2. Combination and Permutation

If HP going to make the update for the 40th Anniversary maybe on the HP-12C Platinum Edition that 2 functions should be added. I hope.

Gamo

That's an interesting list Gamo. In my perspective, the TVM solver can handle the Cost, Price, Markup, & Margin so I find myself not needing that. But I do agree with the combination + permutation. Thanks for sharing Gamo.

Gene. Thanks for the reply. I learned a lot about the HP 10bii+, a calculator I can't try out beforehand via emulator. However, I enjoy RPN and programming so I don't think I'll buy one. I'll stick the the 12C, especially since the Voyager series is my most favorite calculator series of all time.

Really all I would like is built-in trig functions, partial-year depreciation, and being able to use multiple programs without remembering program lines. But I don't think any of these suggestions are practical and necessary.

[martinot]

I would like to complement my scientific calculators with a good financial one.

Requirements:

As Gene points out I would like it to preferably also do trig functions.
I would also like it to have RPN as an option (if possible).
It should be possible to buy new from somewhere (even if no longer in production).

What do you recommend:

HP 12C Platinum (or other models).
HP 30b
HP 17 B II Plus

Any other models to consider (still possible to somewhere buy new)?

[grsbanks]

(02-20-2018 08:49 AM)martinot Wrote:  As Gene points out I would like it to preferably also do trig functions.
I would also like it to have RPN as an option (if possible).
It should be possible to buy new from somewhere (even if no longer in production).

I'd be surprised if you found a financial machine that does trig.

The obvious choice is the HP-12C Platinum, which can operate in algebraic or RPN modes. The default is RPN. They can be found new. If "not new" really isn't a deal breaker then you can also find plenty of HP-12C machines in as-good-as-new condition on TAS among other places. I have 2 or 3 of them in pristine condition.

Another option you might like to consider is a full-blown scientific calculator that also has a finance application built in. I'm thinking of the HP Prime here. It'll do some RPN, although it does seem to be a bit of an afterthought and you can only program the Prime in HP-PPL (a Pascal-like language, but damn fast because compiled rather than interpreted) but it is still available new in some places. The finance application was added, I believe, with the latest firmware update released last month.

I can't speak to the other HP machines you mentioned because I have neither one in my collection. I do have examples of the 12C, 12C Platinum and Prime.

[Gene]

The HP 10bII+ and HP 20b/30b do Trig and statistical distributions.

20b/30b do RPN, 10bII+ is Algebraic only.

12cp no trig, missing newer financial functions and limited stats. Has RPN.

[rprosperi]

(02-20-2018 12:47 PM)Gene Wrote:  12cp no trig, missing newer financial functions and limited stats. Has RPN.

Note that the 12C and 12CP do not have Trig built-in, but programs have been shared that do provide these capabilities, they are easy to find on this site. On the 12C, I believe they take up most of the available program steps, but on the 12CP there is still some space available for your own programs.

What you really want is the HP-27SII (adding RPN) but alas, HP never released this one. A real pity.

Edit to add:

The 17BII+ (Silver) is a great machine, only lacking built-in Trig from your requirements. Again, Trig functions have been written/tested using the built-in Solver feature. The solver language is arcane for very complex use, but for most normal equations, is easy to learn and use.

Personal gripe: The 30b and especially the 20b have horrible keyboards, and also frustratingly cramped LCD displays. Too bad, as they're otherwise nice machines.

[Eddie W. Shore]

(02-20-2018 08:49 AM)martinot Wrote:  I would like to complement my scientific calculators with a good financial one.

Requirements:

As Gene points out I would like it to preferably also do trig functions.
I would also like it to have RPN as an option (if possible).
It should be possible to buy new from somewhere (even if no longer in production).

What do you recommend:

HP 12C Platinum (or other models).
HP 30b
HP 17 B II Plus

Any other models to consider (still possible to somewhere buy new)?

On that list, only the 30b offers trig functions that you would not have to program those functions yourself. If you decided on the HP 12CP or HP 17B II+ there are resources that have programs and equations to calculate the trig functions.

All three listed have RPN as an option.

The most readily available would be the HP 12C Platinum.

If you decide on the HP 12C Platinum or and don't mind carrying around two calculators (instead of programming all the trig functions all the time only to erase it because something else is needed), consider complimenting it with a compact scientific calculator, like the Casio fx-260 (it's $10 or less)).

The HP 10BII+ is an alternative, however it is algebraic, not RPN, and it is not programmable. But you get the trig functions in addition to everything else Gene has listed out of the box.

[TheKaneB]

So far I like the 30B, it has RPN, programming and trig functions, and the solver is really fast. It's a neat business calculator.

[martinot]

I forgot that I would see it as a bonus if I can print from the business calculator.

[pier4r]

After reflecting a bit, wouldn't be easier to have a scientific programmable calculator with a couple of business formulas programmed rather than a business calculator?

I am not an expert of business functions but are they so complicated?

Example.
Instead of a 12C with a program with trig functions, a 15C with a program and business functions?

[Gene]

Quite right Pier4r.

That's why I use the 41CL for all my business stuff.

Sandmath, Extended Stats give me more than enough business functions... plus nearly every math thing I've ever heard about.

[martinot]

Maybe I should just use my DM42 also for financial calculations (have to check what software I can use).

[rprosperi]

(02-21-2018 06:33 PM)martinot Wrote:  Maybe I should just use my DM42 also for financial calculations (have to check what software I can use).

The HP-42S "Programming Examples and Techniques" manual include several ready-to-use business-related programs, including a couple TVM programs built around the Solver.

This manual is available from several places including the MoHPC USB document set, TOS, etc.

[TheKaneB]

(02-21-2018 04:08 PM)pier4r Wrote:  After reflecting a bit, wouldn't be easier to have a scientific programmable calculator with a couple of business formulas programmed rather than a business calculator?

I am not an expert of business functions but are they so complicated?

Example.
Instead of a 12C with a program with trig functions, a 15C with a program and business functions?

It depends... if you only need certain functions and don't want to learn how to program, you buy the correct device and get instantly productive after a few hours with the manual. It's really a "right tool for the job" situation. The user's interface of the 12C is practically perfect for TVM calculations, everything else would be less than optimal. You can assign functions to any keys in the 41C, 42S, etc... true that, but why buy a spaceship if you are only going to use it to get the groceries?

[Gene]

BECAUSE it would be a spaceship man! :-) lol