Attention

This version of tutorial covers a somwhat older version of EasyCalc. I do not have currently time to update it to the latest version. Any contributions are welcome.

Overview

EasyCalc is a graphing, scientific calculator for Palm's and PalmPilots. Of course it has all the capabilities and ease-of-use of the built-in "4-Banger" that comes with the PalmPilot, but also includes trigonometric functions, financial functions, complex numbers and graphing. In addition, you can define your own functions and variables with names up to 10 characters long and nesting up to ten levels deep. Values may range between 1E-100 and 1E250.

Other features:

Basic calculations

Let's start with something very simple. After starting a calculator, you should see something like this:

And now let's compute a very simple thing: 3+3=6. Type in '3+3' using either the buttons on the screen or graffiti and press 'EXE' or write the newline graffiti. '6' will appear in the result area. And now to something more complicated - let's compute '3*sin(pi/2)'. First change to the 'Scientific' screen - tap the 'S' in the top right corner or use menu.

Now you can easily write in '3*sin(pi/2)' and press 'Exe'. You can change between the screens, if you don't like graffiti. You can see somewhat shorter expression on the screenshot - EasyCalc doesn't require closing brackets ('sin(pi+1' is interpreted as 'sin(pi+1)'), and supports shortened writing of multiplication - like '3pi' or '6e'. Before proceeding - try tapping the small black arrow to the right of the input field. What you see is history list, currently holding 15 last executed expressions. You may wonder, what is the Ans button for? It's for the last computed result. And the ans variable gets inserted automatically whenever you are on the beginning of the line and press some 'operation' button. Try writing sin(pi) and press Exe. Now tap a button +. On the screen appears ans+. Now if you complete the expression (e.g. with 1) end press Exe, you have effectively computed sin(pi)+1.

Goniometric calculations

 
There are some comfort functions for working with degrees and radians. They are located in a small menu, that appears when you click the 'M' on the right side of the results field. It features - among others - the '->Degree' and '->Radian' function, that changes the ouptut to a more readable form. Of course you can try the 'Copy' option and Paste it into the input field - and it works. The degrees are written somewhat easier this way: . Of course only if you learn, how to write these special characters (bold dot and degree). The Degree/Radian/Grad can be switched in Preferences.

Preferences


Integer calculations

Tap the 'I' on the top and change to the 'Integer' screen:

EasyCalc works with 32-bit unsigned integers and supports simple binary operations - AND(&), OR(|), ShiftLeft(<) and ShiftRitght(>). It also supports base conversions. Write in some number and press the 'Exe' key and the number will appear in the Result area. Now tap on the base you want to convert to and the number will reconvert. If you convert from 'Float' to some integer base, the number gets rounded. DO NOT FORGET TO CHECK THE MODE BACK TO FLOATING, you can be surprised to see BAD results if you do not (3/2 in integer is not the same as 3/2 in floating point). BTW: If the result is longer than the result field, a small arrow appears on the right and you can scroll the field by touching the field and moving with the pen left/right.

Complex calculations

 
EasyCalc supports all ordinary computations with complex numbers (please, write me if you find some operation EasyCalc doesn't support, it is possible I forgot some of them). The 'i' works exactly as expected. On the second figure you see the result of number conversion in the 'M' menu.

Variables and functions

EasyCalc supports unlimited number of variables and functions. Variable (or function) name consists of lower-case letters and can be up to 10 characters long. Variables and functions share the same address space, so if you define a variable with same name as function, the function will be overwritten. Variable is defined simply by executing 'name=value', function is defined by executing 'name()="code"'. The 'name' cannot be 'pi', 'e' and 'x' as those are reserved identifiers. Parameter of a function is always 'x'. And now some examples: writing a=31 and tapping the Exe key will assign a number 31 into variable a. From now you can treat the a variable like other constants. If you now write a=3*a, variable a will contain a number 93.
Let's try to define a simple function now: write f()="x^2" and press Exe. From now you can use this a function - f(3) will return a result of 9. For working with variables is very helpful a Definition screen (you can tap the D letter on top of your screen). You can easily delete/modify all defined functions and variables.

Financial calculator

Introduction to funancial calculations

Basic financial calculation can be characterised this way: You have some money in the bank (PV, present value). X-times a year(P/YR, payments per year) you deposit some money (PMT, payment) into you bank account. Bank adds every year some amount of money, it's a percentage of the amount that is currently on your account and the percentage is called interest (I). After a given number of years (N, Number of deposits) you decide to withdraw your money from bank. What you will get from bank is a future value(FV). End of introduction.


This is a basic implementation of financial calculator. You work with 6 different variables:
I - interest. Note: from the 1.01 version this should be a per-cent number, e.g. 12% interest should be written as i=12 and not as i=0.12, like in earlier versions.
N - number of years
PV - present value
PMT - payment (annuity) every year
FV - future value
P/R - payments per year
and the Begin/End buttons, that affect when is the payment done - in the beginning of the year or at the end (usually at the end).
Now you can try defining 5 variables and by tapping on the name of the 6th it gets computed. Let's try an example:
By tapping on the buttons 'Undedfined' near names of corresponding variables enter values for every variable. Now most of those 'Undefined' messages should have disappeared. If you tap on the name of the variable you wanted to compute, a notice 'Please wait' will appear in the middle of the screen indicating, that the calculator is computing, and you'll be able to read the result as soon as the sign disappears.

Graphs

EasyCalc can display functions on the graph. Define a function 'f()="x^2"' and change to the 'G' screen and tap on the 'Add' button.

If you tap on the graph, you can see a cross following graph of the selected function and you can read values of that function. Do you want to zoom in? Tap the '+' button and draw a rectangle on the graph area. You can also change graph limits in Preferences (Menu-Graph-Preferences).

Other functions

EasyCalc can guess a number - suppose you just computed 'acos(0)' and you don't know, what the result means. Use the M->GuessIt and it will tell you, that you just got 'pi/2'.

There are some undocumented functions:

Contact, Newest information etc.

It might be useful to read documents you get with EasyCalc, especially 'INSTALL'.

EasyCalc was written by Ondrej Palkovsky, ondrap@penguin.cz. Newest informations are available on http://www.penguin.cz/~ondrap. It would be fine, if someone did language correction of this tutorial, as English isn't my mother language.