Greetings from Seattle - and a short review of the PCalc App. (Updated 4/28/2014)

I am in at the 1st Ave and Pike St Starbucks: the original Starbucks. Actually, the first one opened that first opened in 1971 moved to this location in 1976. The original Pike Place Brew is strong! Thankfully the coffee mellows after a while.

It is a dream of mine to blog from here. Thank you Starbucks! (Twitter: @starbucks)

Short Review of PCalc

This was recommend to me by bb010g. Thanks for the recommendation!

Prices:
PCalc Lite: Free (basic scientific calculator - Algebraic and RPN modes)
PCalc Full: $9.99 on iOS. (Includes Engineering functions, additional themes, conversions, programmer pack - base conversions and Boolean logic - each can be purchased separately)

Also available on Mac, but not available on Android devices.

Developer: James Thomson (Twitter: @jamesthomson)

I have the full version on both my iPad and iPod Touch. I like the intelligent layout of the keyboard, especially on the iPod Touch. The keys are big but you can still access all the major functions without much trouble. The choice of settings are plenty: everything from calculator settings to whether sound the keys make, if at all.

The features such as conversions, constants, and custom functions are accessed through the A>B, 42, and f(x) keys respectively. Each of the menus offers its options in a style consistent to standard iOS devices.

The calculator app has 10 memory registers and 16 other temporary registers that are used for programming. You can program custom functions. While the language does not contain loops, it does include relational testing (if true then skip n steps). Instead of working with the stack, you work with the memory and temporary registers, which takes a little getting used to. I hope to publish future posts explaining PCalc programming language in detail in the near future.

Here is a little sample of snippets I learned with the PCalc Programming:

The commands are constructed using proper English. (e.g. "Multiply M3 by M1", "Set R0 to 22/15")

Arithmetic Operators: Execute (add, subtract, multiply, divide) on a designated register with a certain value. The result is stored in the designated register.

Register X is the "display". Use this register to display your final answer. (Assuming your function has only one output).

To take the absolute value (on register X for example), execute the following steps:
Power X by 2
Power X by 0.5

PCalc is a great calculator app worth looking into. Website: http://www.pcalc.com

Update 4/28/2014:

Thanks to Terry for alerting me to this:  In Radians mode, cos(1.57079632) returned an answer of 6.7948967066 x 10^-9, which is not accurate.  Checking with Wolfram Alpha and with several calculators (HP 32Sii for example), cos(1.57079632) returns the correct answer of 6.7948966... x 10^-9.   Hopefully, this gets corrected in the next update.  

I checked cos(pi/2) and PCalc was accurate with answer of 0.

This ends my blog entry for now - off to see Seattle! Talk to you all soon! Thanks for the comments, recommendations, corrections, and compliments. As always, they are much appreciated.

Eddie


This blog is property of Edward Shore. 2014

The Weekend's Here: A preview of what's coming next.

Hi everyone! I am at a local Starbucks. Love the coffee shop atmosphere - and coffee.

Way I doing today and over the next few weeks is taking some programs from the classic Hewlett Packard manuals, particularly the 1970s (25, 45, 67, 33E, etc) and programming them on today's calculators (35S, 39gii, 15c LE, 50g). I expect that I will end up using resources from Texas Instruments and Casio as well. I aim to post some programs on my blog starting in May.

Have a great and fun weekend! Thank you for your continual support and comments!

Eddie


This blog is property of Edward Shore. 2013

Spring has Sprung: Pocket Ref, TI-30XA, Old HP Manuals, Review and more HP 39gii is coming

Hi everyone! Greetings from the Starbucks in Azusa, CA. Today's blog entry is a hodgepodge. Part 5 of the HP 39gii Programming tutorial - I am planning to have that ready by next week; totally apologize for the long delay.

I am very thankful my family is doing fine and my dad and uncle are both home from the hospital.

Pocket Ref: A Book of Everything?

While at Harbor Freight I found this book: "Pocket Ref 4th Edition" compiled by Thomas J. Glover; picked it up for $10. This reference edition has practically everything technical: physics, computer, mechanics, construction, automotive equations, electrical engineering equations, table of elements and chemical molecules, weights, densities, and perpetual calendars; just to name a few topics. This book has become a permanent part of things I take everywhere. Hopefully this reference will be used for future blog entries.

The TI-30XA: Then and Now

I finally broke down and got a new version of the TI-30XA by Texas Instruments. I have been resisting it for so long since I preferred the solar version over the battery version. What got me to finally purchase it is the article I saw on www.datamath.org, which details the logarithm bug.

Basically, the calculation goes haywire for:

(1) ln(1+x) when x is really small, and

(2) (1+1/n)^n for really large n.

I tested both calculations for the calculators. I also used the built in calculator in the google.com search engine. If you type in a mathematical calculation in google, it will get you the answer! Google also handles conversions and graphing functions.

Both the TI-30XAs (solar and battery) returned the same answers, so nothing has changed in the algorithm.

(1) ln(1 + x)

x=10^-2
TI-30XA: 0.009950331
Google: 0.00995033085

x=10^-8
TI-30XA: 0.000000001
Google: about 9.9 x 10^-9

(2) (1+1/n)^n

n = 10^2
TI-30XA: 2.70481383
Google: 2.70481382942

n = 10^8
TI-30XA: 2.7183727
Google: 2.7182817935


Out of curiosity, the TI-84+ agrees with Google. So this is a cautionary tale with the TI-30XA: be careful with arguments involving 1+x, where x is real small (like powers of 10^-6 or smaller) in any calculations involving logarithms and powers.

On the plus side, the battery TI-30XA retains memory when the ON button is pressed and the numbers are larger and in bold.

Review of the TI-84+ Color Silver Edition Coming Soon

Speaking of Texas Instruments calculators, my TI-84+ C Silver Edition is going to arrive at my doorstep in the coming week. That was my birthday present to myself. By clicking in this sentence, you can read how I initially felt about the TI-84+ CSE. I did read good reviews about it (This sentence is a link to one review, done by Christopher Mitchell (Cemetech). )and will give an impression when I actually have a TI-84+ CSE in my hands.

Old Hewlett Packard Manuals: They have a calculation manual for everything!

Back in the 1970s and 1980s, when pocket calculators were in their beginning stages, Hewlett Packard released detailed calculator manuals for not only their products (HP 35, HP 45, HP 67, etc), they had manuals covering almost every topic conceivable. To name a few: engineering, finance, games, biology, and one even covered astrology. Every now and then I like to study some of these manuals and try to see if I can do it (mostly with today's calculators). It is a really fun way to pass the time.

Several years ago, I ordered the DVD that contains a collection of manuals from The Museum of HP Calculators. You can order the DVD by clicking on this link.. The link will contain another link of the manuals the DVDs contain. I hope to refer to these manuals in future blog entries.

So, more HP 39gii Programming Tutorial, a review of the TI-84+ CSE, and more is coming. Thank you as always and take care,

Eddie


This blog is property of Edward Shore. 2013