QuickCalc for Alfred 2

An alternative calculator for Alfred 2, supporting custom functions and variables, automatic parentheses matching, and percentages. It also supports k, m, and b (or thousand, million, and billion) as suffixes on a number.

It's essentially a wrapper around bc with a few extras added in.

Installation

Simply download the workflow and open the file. You'll need to have the Powerpack to install workflows.

Default functions

I've tried to add support for most of the functions from Alfred's advanced calculator.

Supported functions: sin, cos, tan, log, log2, ln, exp, abs, sqrt, asin, acos, atan, sinh, cosh, tanh, asinh, acosh, atanh, ceil, floor, round, trunc, rint, near, dtor, rtod, pow, logx, mod, min, max.

Most of these should be similar to the implementation of Alfred's advanced calculator, but there are a few additions:

• pow(x, y) can be used to raise x to the power of y, without the integer limitations of the ^ operator in bc.
• logx(base, x) lets you get the log of a number with a defined base (log calculates with a base of 10 and log2 with a base of 2).
• mod(x, y) performs the modulo operation.
• dtor(d) and rtod(r) converts between degrees and radians (this is part of Alfred's calculator, but I'm documenting them here since googling them doesn't turn up useful results).

Defining custom functions and variables

After using the workflow at least once, you can find the custom functions/variables file at "~/Library/Application Support/Alfred 2/Workflow Data/com.clintonstrong.QuickCalc/custom.txt"

Here's an example custom.txt file:

define f2c(q) {
  return (q - 32) / 1.8
}

define c2f(q) {
  return 1.8 * q + 32
}

tax = 8.25%

vat = 20%

In this case, I just defined some functions to convert between celsius and fahrenheit, and set up some variables to use in calculations. It uses the syntax of GNU bc.

Known bugs and limitations

When using functions that take multiple arguments, use both a comma and a space to separate the arugments. This is necessary since commas and spaces can be used as thousands separators. For example, use min(5, 10) instead of min(5,10).

Because percent signs % are used for percentages, you'll need to use the mod function for modulo. For example: mod(10, 3) evaluates to 1.

Due to limitations with bc, the exponentiation operator (^ or **) doesn't allow numbers to be raised to the power of a float (a number with digits after the decimal place). To get around this, you can use the pow function. For example, pow(2, 2.5) evaluates to 5.6568.

Percentages don't work as expected within functions. They still get converted (by dividing by 100), but it doesn't work correctly with addition and subtraction (100 + 10% evaluates to 100.10 rather than 110). Percentages should still work fine outside of functions.

The workflow currently doesn't have support for detecting locales. It expects a period . to be used as a decimal point, with commas, underscores, or spaces as optional thousands separators.

More info

• bc OS X Manual Page
• bc programming language on Wikipedia
• phodd's collection of functions, some of which are used here.