HP HP48GX RPN Expandable Graphic Calculator

The 48GX is no slouch. Its colorful array of buttons lets users tap into 2,300 built-in functions, 300 of which are built-in formulas and scientific constants that encompass the spectrum of the mathematical and scientific fields. It handles everything from basic algebra equations to advanced trigonometric and statistical calculations. Best of all, if the 48GX doesn't have a feature you desperately need, you can use the built-in object-oriented programming language to create functions from scratch. You can then label your creations and access them as you would any other feature that is integrated with the calculator.

The 48GX uses reverse polish notation (RPN, also called postfix notation), which can be difficult for beginners to grasp, but advanced students and professionals will appreciate RPN's elegance and relative simplicity. An optional connectivity kit lets users connect the device to a PC to download new equations and software, and the integrated infrared port lets you share data with other calculators or output your graphs, plots, or other results to a separately available infrared printer. Typical students may want to opt for a less expensive (and less expandable) calculator in the 48 series, like the 48G+, but for those who demand the best and may need more than 128 KB of memory, the 48GX is the clear choice. --T. Byrl Baker

Pros:

• RPN can speed data entry with practice
• Expansion slot adds extra memory and software options
• Programmable, so you can add nearly any feature you like

Cons:

• Cluttered keypad
• Learning RPN and basic object-oriented programming can be daunting for the uninitiated

With RPN, there is very rarely any need for a named variable and it only took me about an hour to start using this calculator for fairly complex EE homework. One of the things I noticed about RPN fairly quickly is that if you're doing complex calculations, you'll often build up intermediate values and then bring the intermediate values together at the end. My study-buddies were always writing down their intermediate values, I just left them on the stack while I did the other calculations. More often than not, those previously calculated values were exactly where I needed them when I needed them later. Everyone else was punching back in the values that they had previously written down (with the possibility of error on each transcription) or trying to remember which variable they had stored them in.

I don't mean to ding the TI approach, I used to work at TI and I think they make a great product. I simply think that the HP has a subtly better philosophy of calculation and a massively better keyboard in the 48s/sx/g/sx line of calculators.


The Mercedes Benz of Calculators   January 12, 2004
 11 out of 11 found this review helpful

Being a college professor of Electrical Engineering for over 30 years, and having used numerous brands and models of calculators and having written reviews of some of them for various publications, there is no doubt in my mind that the HP48GX is indeed head and shoulders above all the other calculators (even the HP49). The RPL entry system is a natural and easy to learn process that mimics the pencil and paper approach that we've all learned in Grammar school arithmetic. The efficiency of input and the ease with which it handles comlex-number calculations is second to none. Formulae can be entered with mixed units and the calculator automatically performs internal conversions to present the answer in whatever valid units you desire. It handles 2-D and 3-D vectors with all the corresponding mathematical operations seemlessly. The infrared connectivity (wireless) and RS232 port (wire) both allow communication between another HP calculator and your computer. This calculator has the right mix of 'function per key' versus 'menu per key' that makes it very easy to negotiate.
One can enter a formula in algebraic notation and the calculator can solve for one of the variables in symbolic and/or numeric form (if all the other vales are specified). The keystroke error recovery facility is superb. A couple of days with this calculator and most people cannot go back to their old 'Algebraic Operating System' calculators, with its cumbersome parenthesis, without making a mistake.
There is not enough space here to praise this calculator to the extent that it deserves. Over the years with all the students and professionals I've had contact with, I know of no one who has ever regretted purchasing this calculator except for the fact that they realized that they waisted money on purchasing their AOS calculators.