I'm saddened that people are still trying to retrofit the desktop calculator idea into a modern PC. A calculator was designed around several difficult to change constraints. The physical size of a calculator had to be small, so the display area was small, the buttons were small (and often overloaded multiple times with multiple functions), the storage was small (often only 1 memory plus the accumulator), and the computational power was small. With a modern computer none of these things are true. A computer has no constraints on being small enough to be portable. A computer has practically unlimited memory and processing power compared to a desktop calculator. A computer has a display that is stupidly larger than any calculator ever had. A computer has persistant storage. A computer doesn't need to conserve battery power.

gcalctool irritates me because it limits itself to what a calculator a fraction of the size (and cost!) can do. The calculator doesn't need big hunky buttons to press for numbers, we have a numeric keypad for that. A computer calculator may have some shortcut buttons for some advanced mathematical functions that are not immediately obvious how they should be entered. A computer calculator must have a history, one that is preserved over restarts. Instead of 10 memory locations like gcalctool, an unlimited number of named variables should be used. instead of "m1" people should be able to use "cost_per_unit". Constants (such as "i", "c", "e") should also be built in, as well as changing values eg, a share price. Unit conversion is very important. Unix traditionally has had a units(1) tool that allows converting between units. The primary use of google's calculator that I have seen has been for unit conversions. All values should be able to have a unit added to them, and the unit should be processed as an intimate part of a value. Some unit conversions can be done dynamically on the fly by finding the conversion via SOAP. (Eg, conversions between currencies). Variables can also hold expressions which automatically update, and should be saved between sessions. I've started work on a prototype calculator like this. The main screen looks like: http://coders.meta.net.nz/~perry/dump/calc1.png http://coders.meta.net.nz/~perry/dump/calc2.png Entering an assignment saves the value, and stores it in the "watches" part of the window (which automatically pops open). eg: http://coders.meta.net.nz/~perry/dump/calc3.png More complicated expressions can be entered: http://coders.meta.net.nz/~perry/dump/calc4.png and, will continue to update if their dependants are changed: http://coders.meta.net.nz/~perry/dump/calc5.png Units can also be used: http://coders.meta.net.nz/~perry/dump/calc6.png Anyway, thats what I think a computers desktop calculator should be able to do.

Posted by Perry Lorier on September 25, 2004 at 10:17 PM PDT #

Rich-

Great work, I use gcalc daily and will certainly take advantage of the extra digits after the decimal point.

PS: nit pick: displaying (or calculating) more places after the decimal is not the same as adding more significant places. The number of significant places is determined by the input data, nothing more.

12.1 / 11.2 is *really* 1.08, if reported as 1.08036 the extra 0.00036 portion is meaningless.

12.1000 / 11.2000 = 1.08036

-JPL

Posted by JPL on September 26, 2004 at 09:26 PM PDT #

JPL: I understand what you are saying (and I saw that a lot recently when I was reading books on electronics), but [g]calctool has always worked that way. Perhaps we need yet another option to select the prefered output format...

Perry: note that gcalctool is trying to satisfy a lot of different kinds of users. From my mother-in-law, who's only ever used a simple hand-held calculator before, right through to engineers who need all the extra scientific functionality. I agree, that others like you would prefer something like Qalculate, but just having Qalculate would confuse my mother-in-law no end. Perhaps both types of calculator should be offered by default.

Posted by Rich Burridge on September 27, 2004 at 07:22 AM PDT #

Hi John. Yes, I definitely think this feature could be on the cards. Maybe not for GNOME 2.9/10 as we want to shake out any potential bugs from adding in the arithmetic precedence (AP) support, but hopefully soon after that.

Having the AP support will make the "tape" display look nicer. You'll be able to see the complete calculation easily.

This feature, b.t.w. is in the TODO file. Added by Sami, the person who did the AP support. See the:

* New display 
  - History of previous expressions (scrollable)

line here.

Posted by Rich Burridge on October 02, 2004 at 06:52 AM PDT #