ConvertAll ReadMe

# ReadMe file for ConvertAll

## a unit conversion program

Written by Doug Bell
Version 0.5.0
April 23, 2010

## Contents

- Background
- Features
- Legal Issues
- System Requirements
  - Linux
  - Windows
- Installation
  - Linux
  - Windows
- Using ConvertAll
  - Basics
  - Combining Units
  - Shortcuts
  - Unit Finder
  - Options
  - Non-Linear Conversions
  - Command Line Usage
- Revision History
- Questions, Comments, Criticisms?

## Background

Why write another unit converter? There are plenty of them out there. Well, I couldn't find one that worked quite the way I wanted.

With ConvertAll, you can combine the units any way you want. If you want to convert from inches per decade, that's fine. Or from meter-pounds. Or from cubic nautical miles. The units don't have to make sense to anyone else.

Since I'm not in the software business, I'm making this program free for anyone to use, distribute and modify, as long as it is not incorporated into any proprietary programs. If you like the software, feel free to let others know about it. And let me know what you think - my email address is doug101 AT bellz DOT org

## Features

- The base units for conversion may be either typed (with auto-completion) or selected from a list.
- Units may be selected using either an abbreviation or a full name.
- Units may be combined with the "*" and "/" operators.
- Units may be raised to powers with the "^" operator.
- Units in the denominator may be grouped with parenthesis.
- Units with non-linear scales, such as temperature, can also be converted.
- A unit list may be filtered and searched.
- Recently used unit combinations may be picked from a menu.
- Numbers may be entered on either the "From" or the "To" units side, for conversions in both directions.
- Basic mathematical expressions may be entered in place of numbers.
- Options control the formatting of numerical results.
- The unit data includes over 500 units.
- The format of the unit data file makes it easy to add additional units.
- Command line options are available to do conversions without the GUI.

## Legal Issues

ConvertAll is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either Version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY. See the `LICENSE` file provided with this program for more information.

## System Requirements

### Linux

ConvertAll requires the following libraries:

- Qt (Version 4.1 or higher - see Trolltech for more information)
- Python (Version 2.3 or higher)
- PyQt (Version 4.0 or higher - see Riverbank for more information)

### Windows

Using the files provided in the binary distribution, ConvertAll should run on any computer running Win 95, 98, NT, 2000, XP, Vista, or 7.

## Installation

### Linux

Extract the source files from the convertall tar file, then change to the `ConvertAll` directory in a terminal. For a basic installation, simply execute the following command as root: `python install.py`

To see all install options, use: `python install.py -h`

To install ConvertAll with a different prefix (the default is `/usr/local`), use: `python install.py -p /prefix/path`

### Windows

Simply execute the downloaded installation file (`convertall-x.x.x-install.exe`). It will install the program with its libraries and optionally create file associations and shortcuts.

If you wish to modify the source code or write your own PyQt programs for Windows, do not use the above procedure. Instead, you need to install Python and the binary for PyQt. Then extract the source code and data files from the Linux version (convertall tar file) to a directory of your choice and execute the `convertall.py` file.

## Using ConvertAll

### Basics

Simply type a unit name in the "From Unit" edit window. As you type, the list below the window will scroll to show unit names which are close matches. Either type the complete unit abbreviation or unit name or hit the return key to use the unit highlighted in the list. Of course, clicking with the mouse on a unit in the list will also add the unit to the edit window. You may also use the up and down arrow keys to select nearby units from the list.

Repeat the unit selection in the "To Unit" edit window. When done, if the units are compatible, you will see the numeric edit windows below the unit lists activate. A number may be entered into either numeric window and the other window will display the conversion result.

### Combining Units

The real strength of ConvertAll lies in its ability to combine multiple units. Simply type the unit names with an '*' or a '/' between them. This allows the entry of units such as "ft*lbf" or "mi/hr". The '^' symbol may be used for exponents, such as "ft^3" or "ft*lbm/sec^2". Negative exponents are allowed for units such as "sec^-1" (per second), but may switch the multiplication or division symbol ("ft*sec^-2" becomes "ft/sec^2").

Multiplication and division have the same precedence, so they are evaluated left-to-right. Parenthesis may also be used to group units in the denominator. So "m / sec / kg" can also be entered as "m / (sec * kg)". The version with parenthesis is probably less confusing.

The buttons below the unit lists ('X', '/', '^2', '^3') will also place the operators after the unit nearest to the cursor. The exponent keys will replace the unit's exponent.

Similarly, clicking on a unit from the list generally replaces the unit nearest the cursor.

The "Clear Unit" button below the operator buttons may be used to empty the unit edit window to allow a new unit to be entered.

### Shortcuts

When typing unit names, spaces are ignored, so they may be skipped. It is also generally ignored if a plural form of the unit name is typed. When a partially typed unit is highlighted in the list, hitting enter will complete the name. Also, hitting the tab key will complete the name and move to the next entry field.

The "Recent Unit" button opens a menu of recently used units and unit combinations. The current unit combination is replaced with any selections from this menu.

The number to be converted may be entered in either the "From" or "To" unit side. Standard or scientific notation may be used, or an expression including the normal math operators (+, -, *, /, **) and parenthesis may be entered.

### Unit Finder

The unit finder can be used to filter units by type and/or search for units using a text string. It displays a separate unit list in a new window. The list will be updated based on the filter and search string entries.

Buttons near the bottom of the finder window add the selected unit to the units in the main window. The "Replace" buttons replace an entire combined unit with the selection. The "Insert" button changes only the part of a combined unit that is active (at the cursor in the main window).

### Options

The "Options..." button allows for changing several default settings. These settings are automatically stored so that ConvertAll will re-start with the settings last used.

The first options control the display of numerical results, including the use of scientific notation and the number of decimal places. Be cautious about setting the number of decimal places to a low value, which can result in a significant loss of accuracy. Six places or higher is recommended (eight is the default).

There is an option to set the number of recent units to be saved. Setting it to zero will disable the Recent Unit buttons.

There is an option to hide the operator text option buttons (x, /, ^2, ^3, Clear Unit and Recent Unit). These can be hidden to save space if the keyboard will be used to enter the operators.

Buttons are also included on the options dialog to control the colors of the text fields.

### Non-Linear Conversions

The conversion of some units is non-linear. Examples of these include the Fahrenheit and Celsius temperature scales (due to an offset zero point) and the American Wire Gauge (logarithmic). The non-linear units are labeled as such in the comments column (located to the right of the "Type" column).

These units can be converted only when they are not combined with other units or used with an exponential operator. Otherwise the conversion would not be meaningful.

### Command Line Usage

Conversions may be done from the command line (Linux or DOS console) without invoking the graphical interface. Enter the command ("convertall" on Linux, "convertall_dos" from the Windows binary), the number, the from unit and the to unit (separated by spaces) to do the conversion. Unit names containing spaces should be surrounded by quotes. Or, to be prompted for each unit entry, use the "-i" option ("convertall -i" on Linux, "convertall_dos -i" from Windows).

After the conversion is done, ConvertAll will prompt for a new number to do the same conversion. Or "n" can be entered to start a new conversion, "r" to reverse the conversion or "q" to quit.

For a more detailed list of options, use the "-h" option ("convertall -h" on Linux, "convertall_dos -h" on Windows).

## Revision History

The full revision history can be found in the English version of the ReadMe file.

## Questions, Comments, Criticisms?

I can be contacted by email at: doug101 AT bellz DOT org
I welcome any feedback, including reports of any bugs you find. Also, you can periodically check back to www.bellz.org for any updates.