NEW: HP 15C Collectors Edition

[MavrikVB]

(08-15-2023 05:08 PM)alimylios Wrote:  Hi,

I took a picture from the bezel. It was not like this when I got it. But a few days layer, using the supplied pouch, I noticed it.

I discovered almost the same scratches on the bezel of my HP15c CE after opening the box which is not nice for a new product designated as "Collectors Edition".
Has anyone tried to remove the scratches on the bezel, for example by polishing?

[dlidstrom]

For someone who's new to this calculator, can someone who absolutely luvs it please share: what is the main appeal to you of this little calculator?
Thanks!

[ctrclckws]

(09-19-2023 12:34 PM)dlidstrom Wrote:  For someone who's new to this calculator, can someone who absolutely luvs it please share: what is the main appeal to you of this little calculator?
Thanks!

Size, Capability, Nostalgia for me.

It's small, batteries will last a long time.

Most (All?) functions are handy from the keyboard.

It will handle a large portion of math needs.

[vaklaff]

(09-19-2023 12:41 PM)ctrclckws Wrote:  Size, Capability, Nostalgia for me.

It's small, batteries will last a long time.

Most (All?) functions are handy from the keyboard.

It will handle a large portion of math needs.

+1. I'd add: Highly readable display. Very good (and readable!) keyboard. Programmable. Physically very durable. Something you can rely on.

For me, the main appeal isn't in one particular feature but that it's very good in every aspect. Something like a small simple powerful reliable elegant off-road with a large trunk and virtually no consumption :-)

[Thomas Radtke]

(09-19-2023 12:34 PM)dlidstrom Wrote:  For someone who's new to this calculator, can someone who absolutely luvs it please share: what is the main appeal to you of this little calculator?
Thanks!

The 15C is very different from the calcs you're listing in your signature. No problem using it as basic scientific calculator, but all extended features need studying the manual. It's not obvious how to handle complex numbers and matrices for example. That said, the feature set is amazing, the form factor just cute, the current hardware acceptable. Keys are ok, but the original was better, even Pioneers or the 50G had more elegant feel to the keys, i.e. the 15C CE is a bit noisy.

[Voldemar]

(09-19-2023 06:48 AM)MavrikVB Wrote:  I discovered almost the same scratches on the bezel of my HP15c CE after opening the box which is not nice for a new product designated as "Collectors Edition".
Has anyone tried to remove the scratches on the bezel, for example by polishing?

I think the scratches were formed when the calculator came into contact with the transparent area of the box. Try to put the calculator in the box, there are scratches on the bezel surface where it meets the transparent area of the box, from the inside the area of the box also has scratches.

[Voldemar]

   

[dlidstrom]

(09-20-2023 07:24 AM)Thomas Radtke Wrote:  The 15C is very different from the calcs you're listing in your signature. No problem using it as basic scientific calculator, but all extended features need studying the manual. It's not obvious how to handle complex numbers and matrices for example. That said, the feature set is amazing, the form factor just cute, the current hardware acceptable. Keys are ok, but the original was better, even Pioneers or the 50G had more elegant feel to the keys, i.e. the 15C CE is a bit noisy.

Thanks for the explanations. I can certainly understand the nostalgia factor. This one is definitely from a time before I joined and seems a bit too complicated (for me) to learn in 2023.

[Maximilian Hohmann]

Hello!

(09-20-2023 06:38 PM)dlidstrom Wrote:  This one is definitely from a time before I joined and seems a bit too complicated to learn (for me) in 2023.

For me as well, and I have been into this calculator thing since 1976 or so. Yes, I have a "real" 15C and the "SE" and now the "CE", but, for example, the way compex matrices are dealt with is beyond my comprehension. Well, maybe I could work my through the manual and follow the examples, but if I then need to perform such a calculation three months later I would have to start from scratch again. It is amazing that they were able to put complex matrix algebra into such a tiny calculator, but by today's standards, the way it is done is totally counter-intuitive not even remotely close to how one would do it on a more modern machine. Or an older one with a FORTRAN compiler...

So unless one collects these things the value of their advanced functions (matrices, solver, intergrator, ...) is not really obvious in 2023. Or even in 1993.

Regards
Max

[Steve Simpkin]

(09-20-2023 06:49 PM)Maximilian Hohmann Wrote:  ...
It is amazing that they were able to put complex matrix algebra into such a tiny calculator, ...
...
Regards
Max

I give credit to Professor William Kahan for defining the advanced feature set of the HP-15C and for his assistance in its development.

Acknowledgments for the HP-15C project from the May 1983 issue of HP Journal magazine.

   

[Olivier (WA)]

Finally opened mine (well, one of two, really...), ordered 8-30-23 (from Oxford Educational), received 9-01-23 (Seattle, Washington), held up until my birthday from an understanding spouse...

L/NO 9CJ323
S/N 00410

Olivier

[Thomas Klemm]

(09-20-2023 06:49 PM)Maximilian Hohmann Wrote:  It is amazing that they were able to put complex matrix algebra into such a tiny calculator

The same trick can be used with the WP-34S:
Calculations With Complex Matrices

[rprosperi]

(09-24-2023 11:06 AM)Thomas Klemm Wrote:  

(09-20-2023 06:49 PM)Maximilian Hohmann Wrote:  It is amazing that they were able to put complex matrix algebra into such a tiny calculator

The same trick can be used with the WP-34S:
Calculations With Complex Matrices

True, but it's less amazing 35 years later...

[carey]

(09-20-2023 06:49 PM)Maximilian Hohmann Wrote:  It is amazing that they were able to put complex matrix algebra into such a tiny calculator, but by today's standards…

So true about complex matrices in the 15C. Just as an aside, the handheld matrix feature I still find amazing, available as a built-in feature starting with full CAS calculators, is symbolic matrices. While not as common as numerical matrices (by a mile!), they manage to show up in several math, science and engineering contexts.

The reason I find it still remarkable is that, after the countless times we’ve read in comments the cliche “if I want to do serious work, instead of a calculator I turn to Excel or Matlab or Mathematica or…”; Excel doesn’t do symbolic matrices; Matlab doesn’t without the Symbolic Toolbox, losing some of Matlab’s notational simplicity; Mathematica does symbolic matrices, but their availability on easier to use CAS calculators weakens the argument about serious work not being possible on a calculator.

[Thomas Klemm]

(09-24-2023 02:34 PM)carey Wrote:  the cliche “if I want to do serious work, instead of a calculator I turn to Excel or Matlab or Mathematica or…”

You missed to mention Python:

Code:

from sympy import Matrix
from sympy.abc import a, b, u, v

z = Matrix([[a, -b], [b, a]])
w = Matrix([[u, -v], [v, u]])

w * z.inv()

\[
\left[\begin{matrix}\frac{a u}{a^{2} + b^{2}} + \frac{b v}{a^{2} + b^{2}} & - \frac{a v}{a^{2} + b^{2}} + \frac{b u}{a^{2} + b^{2}}\\\frac{a v}{a^{2} + b^{2}} - \frac{b u}{a^{2} + b^{2}} & \frac{a u}{a^{2} + b^{2}} + \frac{b v}{a^{2} + b^{2}}\end{matrix}\right]
\]

Or I can use WolframAlpha:

Code:

{{u,-v},{v,u}} Inverse[{{a,-b},{b,a}}]

But I failed using symbols in a matrix on the HP-48GX.
And I never bothered to deal with later models.

Here's an explanation on how complex matrices are handled in the HP-15C:
Represent a complex-valued matrix into real-valued matrix

[dlidstrom]

(09-24-2023 08:01 PM)Thomas Klemm Wrote:  You missed to mention Python…
…Wolfram Alpha…

Those are also (mostly?) desktop systems. The HP 50g seems to handle symbolic matrix calculations well. Being able to do this in an unlimited RPN stack is very convenient (IMO).

[Thomas Klemm]

(09-24-2023 08:24 PM)dlidstrom Wrote:  Those are also (mostly?) desktop systems.

I can use both as native apps on my iPhone.
They are also available online.

Carnets Jupyter
Try Jupyter

[John Keith]

(09-24-2023 02:34 PM)carey Wrote:  Just as an aside, the handheld matrix feature I still find amazing, available as a built-in feature starting with full CAS calculators, is symbolic matrices. While not as common as numerical matrices (by a mile!), they manage to show up in several math, science and engineering contexts.

At the risk of dragging this discussion further off topic, what I find more useful than purely symbolic matrices is the ability to use exact integers and fractions in matrices. Not only can we compute the inverse, determinant, etc. without rounding errors, but there is useful insight to be found in the numbers themselves- for instance the smallest denominator in the elements of the matrix inverse. The disadvantage is that exact matrix operations are slower and use more memory than numerical operations.

[carey]

(09-24-2023 11:58 PM)John Keith Wrote:  …what I find more useful than purely symbolic matrices is the ability to use exact integers and fractions in matrices. Not only can we compute the inverse, determinant, etc. without rounding errors, but there is useful insight to be found in the numbers themselves- for instance the smallest denominator in the elements of the matrix inverse.

John,
This is a very useful insight! Thank you for sharing it.
Is the ability to work with exact integers and fractions in matrices limited to HP CAS models or do any other HP models have this capability?
Carey

[GioArca67]

Hi guys, thanks for accepting me.
I have a little collection of HP calcs (28S and 50G) and I apreciate a lot the 15C.
Thus the return in production of this Collectors Edition was a great opportunity to get one.
I received an HP 15C CE from Moravia, shipping was fast to Italy.
Production L/NO. 9CJ323
Serial # 01616
The calculator is great, I had also an emulation on my phone, but I too received a not fully functional unit: the "division" (top right) key do not register properly keystrokes, I have to push harder then all the others, i.e. whilst all the others get recognized almost when you hear the mechanical feedback click, the division no
Really annoying, because you have to constantly check the display and no garantee that in the future wil not be worse.
I tried to press repeatedly the keys a few tens of times, but without improvement.
Sadly asked for an RMA.