Monday, 7 September 2015

Main Calculator Mode

When TLCalc is opened, the main screen is shown for evaluating expressions as well as accessing the other features of TLCalc. The calculator is split into 3 main areas, the input row at the top, the history pane in the middle and the button pad at the bottom. The button pad is moved to the right in landscape mode.

TLCalc Portrait Mode
TLCalc Landscape Mode

To enter expressions, simply type the expression into the input field. E.g. 25+sin(2i


Input can be provided using the button pad or a keyboard. The on-screen keyboard is shown by pressing the keyboard icon. The button pad has [abc] and [2nd] modifiers which activate the similarly coloured text when these modifiers are turned on. You can also tap and hold a button to insert the [2nd] text for that button. This short-cut also works when the button pad is in alpha mode.

Calculator Results and History

A preview of the calculation is displayed below the field. Pressing [Eval] appends the calculation to history. Click [X] to remove that item from history.

If the expression is invalid. In which case “Error in expression” is displayed. Press [Eval] to get a description of the error. 

Press and hold an item from history to open a context menu to copy and paste either that command or its answer to the input. Some commands have no answers that can be copied to the input in which case the copy answer option is disabled.

Tapping on the history item that contains a result will toggle between rectangular, degree polar and radian polar format (see Imaginary Numbers section below).

Constants (e, pi)

There are 3 built-in constants: i, e and pi. To use these, just type them in. E.g. sqrt(-2*pi)-5i.

e must be lower case but the other constants can be in any case. The words e, nCr and nPr is the only time the calculator is case sensitive.

For numeric constants, you can use E meaning multiply by 10 raised to the power of (10^). E.g. 2E3 = 2*10^3 = 2000. The E must be capital otherwise the calculator will assume the constant e is being used.

Imaginary Number (i, @)

i is the imaginary constant and can be used in many functions such as sqrt, sin, cos, etc.

You can type imaginary numbers in using a+bi, a+ib, re^(ti) or r@t where a is the real component, b is the imaginary component, r is the magnitude and t is the angle. The angle must be in radians when using the exponential form but uses the chosen angle mode when using the @ notation. You can also toggle the output type by tapping on the results in history. The letter next to >> indicates the output type where:
  • i = rectangular 
  • p = radians polar
  • d = degrees polar
ReminderTLCalc uses @ to input complex angle (i.e. ∠). This is so you can use a keyboard to type in polar numbers easily.

Variables

See Using Variables.

Operands

This calculator accepts operands: add (+), subtract (-), multiplication (*), division (/), to the power of (^) and modulus (%). The subtract symbol (-) is also used for multiplying the result by -1 like -sqrt(4) = -2.

% is not used as percentage in TLCalc. It is used as modulus which returns the remainder of a division operation. Percentage is not supported outside of Unit Converter mode. (where it can be entered as a unit type)

This calculator supports implicit multiplication. This means that you are allowed to drop the multiplication character when it it is allowed in algebra. E.g. (5)(2(sin(2)+3) .

The * sign is required when omitting * causes the sequence of letters to look like a function (regardless of spaces and capitalization of letters). E.g. a*sin is not the same as asin which is a function.

See also: Order of Operations.

Functions

Many functions are available for you to use and custom functions can even be added to TLCalc (see Custom Functions for more information).  To use a function, type the function name followed by the open bracket and the argument(s) to the function. Most functions only accept one parameter but some accept more in which case the comma is used to separate the parameters. E.g. rect(2,2*pi).

To view a list of functions you can use, tap on [fx…] to show the Insert dialog. From the dialog, tap on a function name to insert it into the input, [?] to view more information about the function or [x] to remove the function (remove applies to custom functions only). You can also insert commands and variables using the Insert dialog.


Some functions have restrictions on their inputs such as factorial which only accepts a positive integer. Specifying an input that is incompatible with the function results in NaN (not a number). Any operations involving a NaN degrade to NaN, e.g. 0*NaN = NaN.

Matrix

From V1.10 and onwards, you can use matrices by typing them in using square brackets [ and ]. Commas are used to separate columns and semicolons to separate rows. E.g. the 2x2 matrix is entered as [a,b;c,d]. Normal matrix operation are considered for addition, subtraction, matrix multiplication, scalar multiplication and integer powers (-1 is the only negative power allowed which calculates the inverse matrix).

Note: Indexing of matrix elements start with 1.

Use of algebraic operations with matrices, especially with operations such as det and matrix inverse is currently experimental. There are some known bugs so use with caution.

Permutation (nPr), combinations (nCr) and factorial (!)

Permutation and combination is input as a nPr b and a nCr b where a and b are non-negative real integers and b<a. Factorial is input as a! where a is a non-negative integer. You can use variables as well but the non-negative integer requirement still holds. Similar to functions, these operations return NaN if you provide invalid parameters.

See also: Calculator Precision and Order of Operations.

Comparisons

Symbol
Meaning
< 
Less than
> 
Greater than
<=
Less than or equal to
>=
Greater than or equal to
==
Equal to
!=
Not equal to









You can use the symbols shown in the table to compare quantities. These operators return 0 for false and 1 for true. These relational operators only work if both numbers being compared are both real or both purely imaginary. Equals checks that both real and imaginary components are equal before returning 1. The not-equals operator checks for difference in either real or imaginary components before returning 1.

See also: Calculator Precision and Order of Operations.

Function Helper

Added in V1.11 is a utility to help you input functions. The function helper displays the function argument’s name and a description on the function. It also allows you to evaluate the function before inserting it into your main expression. To access the function helper, first place the cursor after the opening bracket (but before closing bracket if any) of the function then tap on the [Fx?] button.

Remember to place the cursor somewhere after the opening bracket of the function, not inside the function name. You don’t have to place it directly after the opening bracket but if placed inside nested functions, function helper will display the help for the nested function (since TLCalc can't tell whether you would like to edit the inner or outer function, it will default to the inner function).

Commands

Commands are like sub-programs built into the calculator. They are called by their name followed by a colon (:). All arguments are separated using colons (this is to prevent confusion when the argument contains a comma). The FX Picker lists all available commands in the CMD tab as well as how to use them.

Number Bases