Zeroclickinfo-goodies: Calculator: Edge Cases

[pjhampton]

Description

For Calculator IA edge cases, please comment them below this issue and someone will fix them in due course.

People to notify

@duckduckgo/duckduckhack-contributors

Instant Answer Page: https://duck.co/ia/view/calculator

[Survivor75]

In Calculator IA, ∀ x ∈ - Z . Factorial(x) = -Factorial(-x).
In some cases whenever we need factorial of a negative number ,we take it as, -Infinity.
The factorial function is defined for non-negative integers only.
0!=1
n!=n×(n−1)!, ∀ n ∈ Z
However, we can generalize the factorial function to the Gamma function
Γ(x)=∫∞0tx−1e−tdt.
Note that the Gamma function is undefined for nonpositive integers, though it is defined for every other number, including complex numbers.
Here's a link that I found helpful : https://mathoverflow.net/questions/10124/the-factorial-of-1-2-3

[adityatandon007]

@pjhampton calculator doesn't give the result when trying to calculate roots multiple times

Query

Response

Answer: It should display 2
I was thinking of making this as a separate issue since it is not an edge case but a case that is perhaps missed (or not implemented) but was :fearful: to do so.

[pjhampton]

Yeah, this is an edge case. I can fix soon 👍

[adityatandon007]

Hey, I would like to try but don't know what can be the patch for this. The
calc code has changed a lot from what it used to be. Can you guide me what
changes I have to make to fix this. If i can't then of course you can
always take it.

[tagawa]

Query: https://duckduckgo.com/?q=2+%5E+-53&ia=calculator

Response:

Answer: Not zero.

[tagawa]

Calculator can't correctly multiply with percentages with more than two decimal places. An extra %25 is added to the URL which seems to mess things up. Example:

304*3.1%
Answer: 9.424

304*3.10%
Answer: 9.424

304*3.100%
Answer: 912

304*3.1000%
Answer: 9120

[philipmiesbauer]

Just for clarification. The only correct answer is with 2 decimal places?

On Tue, 28 Nov 2017, 09:34 Daniel Davis, [e-mail] wrote:

Calculator can't correctly multiply with percentages with more than two
decimal places. An extra %25 is added to the URL which seems to mess
things up. Example:

304*3.1%
Answer: 942.4

304*3.10%
Answer: 9.424

304*3.100%
Answer: 912

304*3.1000%
Answer: 9120

—
You are receiving this because you are on a team that was mentioned.
Reply to this email directly, view it on GitHub
https://github.com/duckduckgo/zeroclickinfo-goodies/issues/4391#issuecomment-347465500,
or mute the thread
https://github.com/notifications/unsubscribe-auth/ANKFpceq3zAshDOIFVJ5M2nkWVLLq4KOks5s69O4gaJpZM4OmW7T
.

[philipmiesbauer]

I checked up and the answer to 304*3.1% is also 9.424. so that is correct.
The extra %25 you are referring to is the URL encoded prevent character, %.
The seems to be an issue in the calculation, the URL is working fine.

On Tue, 28 Nov 2017, 09:41 Philip Miesbauer, [e-mail]
wrote:

Just for clarification. The only correct answer is with 2 decimal places?

On Tue, 28 Nov 2017, 09:34 Daniel Davis, [e-mail] wrote:

Calculator can't correctly multiply with percentages with more than two
decimal places. An extra %25 is added to the URL which seems to mess
things up. Example:

304*3.1%
Answer: 942.4

304*3.10%
Answer: 9.424

304*3.100%
Answer: 912

304*3.1000%
Answer: 9120

—
You are receiving this because you are on a team that was mentioned.
Reply to this email directly, view it on GitHub
https://github.com/duckduckgo/zeroclickinfo-goodies/issues/4391#issuecomment-347465500,
or mute the thread
https://github.com/notifications/unsubscribe-auth/ANKFpceq3zAshDOIFVJ5M2nkWVLLq4KOks5s69O4gaJpZM4OmW7T
.

[philipmiesbauer]

I have raised an issue on the IA.

On Tue, 28 Nov 2017, 09:48 Philip Miesbauer, [e-mail]
wrote:

I checked up and the answer to 304*3.1% is also 9.424. so that is correct.
The extra %25 you are referring to is the URL encoded prevent character, %.
The seems to be an issue in the calculation, the URL is working fine.

On Tue, 28 Nov 2017, 09:41 Philip Miesbauer, [e-mail]
wrote:

Just for clarification. The only correct answer is with 2 decimal places?

On Tue, 28 Nov 2017, 09:34 Daniel Davis, [e-mail]
wrote:

Calculator can't correctly multiply with percentages with more than two
decimal places. An extra %25 is added to the URL which seems to mess
things up. Example:

304*3.1%
Answer: 942.4

304*3.10%
Answer: 9.424

304*3.100%
Answer: 912

304*3.1000%
Answer: 9120

—
You are receiving this because you are on a team that was mentioned.
Reply to this email directly, view it on GitHub
https://github.com/duckduckgo/zeroclickinfo-goodies/issues/4391#issuecomment-347465500,
or mute the thread
https://github.com/notifications/unsubscribe-auth/ANKFpceq3zAshDOIFVJ5M2nkWVLLq4KOks5s69O4gaJpZM4OmW7T
.

[mintsoft]

Another one: log 0.000159154944

[AlterationBrick]

Input: 0^0
Answer: 1
This is not correct

[DavidGinzberg]

@AlterationBrick I puzzled over this a bit and finally caved in and searched for it from a few sources. It's a fun question to contemplate.

It looks like 0^0 actually is considered equal to 1 in an algebraic sense. Although there's a lot more to its meaning in different contexts. That's expanded upon both in Wikipedia and Quora.

My intuition here is that given the "numbers on a calculator" context, 1 or undefined would both be acceptable results here.

Is there a different result that you would suggest should be displayed instead?

[pjhampton]

Yeah, I am running with 1 being the correct answer. Regardless, this is a math.js evaluation. The best we can do is override it :-)

[philipmiesbauer]

Since we are never going to make everybody happy with either answer is it
worth linking the answer to the Wikipedia article for further explanation?

On Tue, 6 Feb 2018, 10:32 Peter Hampton, [e-mail] wrote:

Yeah, I am running with 1 being the correct answer. Regardless, this is a
math.js evaluation. The best we can do is override it :-)

—
You are receiving this because you are on a team that was mentioned.
Reply to this email directly, view it on GitHub
https://github.com/duckduckgo/zeroclickinfo-goodies/issues/4391#issuecomment-363380393,
or mute the thread
https://github.com/notifications/unsubscribe-auth/ANKFpTnxRKrJnUJ9zEvMifs_6wCV4H0wks5tSCo1gaJpZM4OmW7T
.

[adityatandon007]

Yes, we cannot satisfy everyone, but I think we should stick with 1 here just because wiki says so.

[AlterationBrick]

Thanks for the responses; I was judging the answer against the output of my
TI-83+ which gives a domain error, but it seems that the consensus in
computing is to grant 0^0 the value of 1. In interests of convenience and
consistency it seems valid to keep it this way. I did not realize that I
had stumbled onto a centuries-old mathematical debate...

On Feb 6, 2018 8:09 AM, "Aditya Tandon" [e-mail] wrote:

Yes, we cannot satisfy everyone, but I think we should stick with 1
here just because wiki says so.

—
You are receiving this because you were mentioned.
Reply to this email directly, view it on GitHub
https://github.com/duckduckgo/zeroclickinfo-goodies/issues/4391#issuecomment-363417211,
or mute the thread
https://github.com/notifications/unsubscribe-auth/AQH8aRtb9_OkOhw2NENp5JF7z394u8bmks5tSE8BgaJpZM4OmW7T
.

[ghost]

Not sure if intentional but inconvenient: enabling caps lock will disable key shorcuts, i.e. pressing "p" for Pi or "c" for cosine will no longer work whilst caps lock is enabled.