General

Use solved variables in other equations
y = 2z + 1
z(3) => 1
z(3) * 5 => 5*z(3) //This should be 588 votes 
Support for (simple) date & time arithmetic
I often find myself needing time calculation, such as the number of hours between midnight and 9:30am. Or the number of days between 25th October 2013 and 25th December 2013.
125 votes 
add a filter function
filter(x > 2, [0,1,4,5]) => [4,5]
With filter, map, and reduce, you'd have the basics of functional programming.
9 votesGreat idea!

Add intellisense
ctrl+space to try to auto complete variables/functions/etc (with optional dropdown).
14 votes 
Add support for series and statistical functions
Specifically, means and std dev’s? Pass a series in and then do average(series), std dev(series), etc.
17 votes 
Multicolumn tables like MultiMarkdown
Support content layout in table form, like described here:
https://github.com/fletcher/MultiMarkdown/wiki/MultiMarkdownSyntaxGuide#tables
18 votesI am also trying to add CSV support for those that don’t like 

Ability to generate random number
Something like foo = rand(1:100) gives foo a random number between 1 and 100
26 votes 
Add some undo functionality for IOS
I cannot find any way to undo some editing in IOS.
If it is implemented please document it.
Otherwise I think that it would be essential to at least have a way to undo recent edits or to revert to a previous version of the file. I had a complex calculation that I managed to seriously corrupt on my iPhone, while trying to change the value of an input variable and I could not find any way to go back...
Thanks for the amazing job!
28 votesIt is not implemented, but will be.

Allow external references to functions and variables in other calca files
Should be able to define the equivalent to an #include operator referencing another calca file. Then it would be possible to reference the functions, and variables defined.
17 votes 
Add date variables
I was trying to set up a countdown calculation (days until x, unless y takes longer) but couldn't figure out how to grab today's date from Google, or how to input another date to compare it to. Not a vital feature, just a possible one.
30 votesI plan on adding more date and time functionality to make this easier.

Compute in Calca like mathematica
its really anoying to type "=" and ">" everytime to compute a calculation.So i made a autohotkey script to make it work just like mathematica (Shift+Enter Style).
Here is my script.You press Shift+enter:
Script Start
+Enter::
IfWinActive ahk_class WindowsForms10.Window.8.app.0.129c866
{
Send {=}
Send >
Send {Space}
}
Return
Script End
This script will only work when Calca window is in focus.Eventually i would want this functuanality to be baked in Calca.I think its really convenient.28 votes 
Add minimum, maximum, average, and sum functions for a list of variables/numbers (maybe standard deviation, etc also)
Be nice to find the max/min of a list/array of numbers or variables, such as x = Min (x1, x2, x3,…) etc.
33 votes 
Support binary shifts (<< and >>)
It would be helpful to me in using Calca as a scratchpad in programming and sysadmin work if I could use binary bitshifts:
4 << 1 => 8
8 >> 1 => 4I know this runs into problems with the sign bit (bug filed), but anything would be better than nothing.
33 votes 
Add some kind of import function
As in the ability to import/include another file..I am thinking simply by filename, and it would look in the relative path of that file. Perhaps this may be a little overboard for this kind of tool, but I was thinking in terms of having common sets of units / functions etc you may use across a set of files.
53 votes 
11 votes
I will be turning off the tap a number feature to prevent these kinds of problems.

format equations with math symbols
Beyond just Greek symbols, I'd love to see Calca produce builtup (or at least linear) equation formatting. (see http://www.unicode.org/notes/tn28/UTN28PlainTextMathv2.pdf)
it'd be cool to consume that markup as input also. :)
keep up the great work!
35 votesI don’t know how advanced I’ll get, but I love these.

Provide a Contributors library online
Provide a repository where users can contribute and share their favorite functions to help quickly extend Calca's capabilities through reuse of proven solutions.
12 votes 
Make it easy to use the result of the previous calculation
Add an easy way (button/syntax) to copy the result of the previous calculation to the current cursor.
31 votes 
Have awnsers in fractions
Is that possible? If so, I would like to know how.
If it isn't, Make that happen. Please.13 votesI have been meaning to add arbitrary precision arithmetic to help with this and cryptography.

Add a keyboard shortcut for the => symbol
Sure, it’s just one less character, but typing => all the time is inefficient, especially to type `=` which is at an awkward pinky location on the keyboard. The iOS app gets it right, with a `=>` shortcut button.
34 votes
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