Challenge #74: Build a Factorial Calculator

We are one week away from the challenge #75 milestone. Some users want to race this one to be the first to 75 and nab the first ever ‘Burgschrund Crevasse’ badge. I will plan to post the challenge on 6/26/2017 at 9:00 AM PST. The main contenders are @SeanAdams, @NicoleJohnson, @LordNeilLord, and @estherb47 barring any other users catching up on a significant amount of challenges this week.

This week, we are going to slow it down and take a breather after our two-week long challenge #73 and shoot for something simpler. This week, the goal is to create a macro that calculates factorials. To find the exact formula, you can find it here: https://en.wikipedia.org/wiki/Factorial. Factorials are commonly used to calculate the multitude of ways a task can be completed – like how many possible results could come from shuffling 52 playing cards.

Factorials are usually represented by ‘n!’ – n being an integer. If we were looking for the factorial of 4, it would be represented as 4!. To calculate the factorial of 4, the equation is written as (4)*(3)*(2)*(1). Below are some example caculations.

1! = (1) = 1

2! = (2)*(1) = 2

3! = (3)*(2)*(1) = 6

4! = (4)*(3)*(2)*(1) = 24

challenge_74_start_file.yxzp

challenge_74_solution.yxzp

Macros

Preparation

Advanced

Transform

Interface

Basic

Accepted answers

All comments

NicoleJohnson

My solution!

Now I'm off to do some pre-race stretching for next week. And polish my out-of-office email so no one bothers me starting at 9am PST on Monday.

Spoiler

I ended up doing some things with converting to string because I was having a hard time with it cutting off my numbers when it got to a long length answer (I tested it with 22, and realized the last few numbers disappeared, so I re-evaluated...). I could be having a total brain block though. Am I missing an obvious field type that would let me have super-long numbers?

At any rate... it works. Especially for factorials 17! and lower.

Cheers! NJ

challenge_74_NicoleJohnson.yxmd

FactorialMacro_NicoleJohnson.yxmc

alex

Here it is.

challenge_74_AC.yxzp

philipmannering

My solution below

Spoiler

And used in the workflow below
factorial use.png

I find it particularly difficult to keep all the input fields, keep the same input names and keep the same field order without a shed load of action tools. Any advice on this?

Factorial.yxmc

patrick_digan

Attached!

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I went with the generate rows tool to generate all the numbers from 1 to n, followed by a multi-row tool to calculate the product. If I can get on my soap box, wouldn't it be great if the summarize tool could take a product? That would have eliminated the multi-row tool/sample combo. Feel free to star this great idea if you agree: https://community.alteryx.com/t5/Alteryx-Product-Ideas/Add-Product-to-Summarize-tool/idi-p/26682

EDIT: @NicoleJohnson I now see that our solutions are nearly identical

challenge_74_start_file.yxzp

LordNeilLord

A nice simple solution, pretty much the same as everyone else

Spoiler

challenge_74_LNL.yxzp

patrick_digan

@PhilipMannering In regards to your action tools, I would make a couple tweaks to avoid this:

1) I would check the box on your macro input about show field map. This is a powerful option where whatever the field name that comes in from the workflow, it converts it to whatever field name is in the macro input. For this case, it would convert the fieldname "Number" to "vals".

2) I would add a select tool at the end, and then connect an action tool from the macro input to your select tool using the "update select with reverse field map" option. This is the way to change vals back to Number so that the user never knows that the fieldname was changed.

3) I would change your join tool so that your field is named vals instead of right_vals. For #2 to work, it has to find the field vals exactly to convert it back.

Now you can delete all the action tools and your interface as well:

Hope that helps!

Factorial.yxmc

Philip

My solution

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Factorial calculator.yxmc

MinaGO

Hi all I've returned after my lack of internet hiatus (plus moving to TheInformationLab)
I think I like the elegance of other people's solutions more but here was how I solved it

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Simona

Nice one! I rarely use the Generate rows tool but it was very helpful in this case.

Spoiler

Below my workflow. I guess something to make it better could be to create an interface, but I made this litterally in 10 minutes.
Factorial macro.PNG

challenge_74_MACRO.yxmc

JSaumya

I have used a generate rows tool followed by the multi row tool and summarize tool. I was working on how several row values can be multiplied and came across this discussion thread: https://community.alteryx.com/t5/Data-Preparation-Blending/Multiplying-lists-of-numbers-together/td-p/56714

Though I did keep using the multi row tool, I didn't get the right configuration to generate the factorial until I found the above link.

@ patrick_digan, thanks for the knowledge! I did star your idea already!

I am just uploading my solution although better versions are available in this discussion already.

FactorialCalculation.yxmc

philipmannering

@patrick_digan Thanks for the reply Patrick. And I think if you use the sample tool you can avoid having to reroute your other fields and then use a join tool.

My only minor criticism of the map field value and reverse field map the names method is a) it's harder to get the output dynamically named as 'input name ' + 'factorial'. So that when you input your field 'field_m' (for example) the output will be 'field_m factorial'. Thereby helping to differentiate from other factorial fields if you plan on using the tool more than once in the same workflow. The second downside is that you can't change the configuration text for your macro. It will always read something like: "Choose input_vals (Byte) Field" and you can't manually change this to something much nicer like "Choose field to get factorial", as far as I'm aware. This is very minor but something that irks me ... often enough to add all those action tools.

MarqueeCrew

Good morning all

I've updated my avatar as well as completed my challenge 74. I am not in the running for the #75 milestone and will cheer the team of @SeanAdams, @NicoleJohnson, @LordNeilLord & @estherb47 on.

In my solution I have addressed the factorial challenge as well as addressed a common macro issue that occurs when you map to incoming data. I will point to @NicoleJohnson who provided a solution that allows a user to map their source data field to a macro variable named NUMBER. In the output to her macro she has renamed the incoming field to NUMBER. If the incoming field name was number, then all is well. But what if the incoming variable wasn't named number? Will the user be happy?

Another solution by @patrick_digan (a 2017 ACE) adds an interface action tool that is set to re-map the macro variable (Number) back to the original field name (when commenting on @Philip's post.

Spoiler

I am glad to solve the challenge so closely to the way that Nicole has solved it. I don't know if there is a string theory that I missed, but I used doubles and didn't seem to have an issue. We handled null values differently but in the end we approximate the same answer.

Cheers,

Mark

Challenge_74_MarqueeCrew.yxmc

amarrero45

Hello Everyone,

I am quite excited for this weekly challenge because of it a list of first for me. It is my first weekly challenge, the firest time I use the generate rows and multi-row formula.

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Factorial Calculator.yxmc

Vignesh-Sunderrajan

Hi All,

My first challenge! Please find my solution below.

Challenge#74-Factorial.yxmc

vishalgupta

Solution

Flactorial.yxmc

SeanAdams

:-) We should declare this "National weekend before Challenge 75"!

My solution is attached below - chose to use an iterative macro (like @MinaGO) - not as pretty or elegant as the row generator solutions that folk have provided, but I've been doing a lot of iterative work at the moment, so I figured why not?

Spoiler

Here's the iterative macro. Very simple - just take each row, check if the multiplier is now <=1; if yes then output; if no, then perform the multiplication; and decrement the multiplier

Because the iterative macro needs to have the same input for each iteration - it would have had to have 2 input channels and 2 output channels. I put a wrapper around this to make it cleaner from the main flow.

Finally - here's the main flow with results

challenge_74_SeanSolution.yxmd

nFactorialIterativeMacro.yxmc

nFactorialPrep.yxmc

estherb47

On the same path as most here. Added a Record ID tool to protect the integrity of the order of numbers entered into the input (so that the numbers don't wind up in ascending order in the output.
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challenge_74_EHB_solution.yxzp

Colgan

only difference in what I made is that I took the "last" rather than the "max" in the summarize tool since the running total calc is sorted.

lminors

Working my way back. Fancied a test on making macros but I feel I will be tested much more in future. Nice simple problem though. Cheers!

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challenge_74_LM.yxzp

MsBindy

Phew! This turned out to be easier than I thought it would.

challenge_74_MsBindy.yxmc

jamielaird

Here's my solution:

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challenge_74_JL.yxzp

Edwin_dup_98

I used R-tool to solve this.

challenge_74_Edwin.yxmd

data_rachel

My solution - looks fairly standard, but I added a few bells and whistles after seeing what others had done (it's my first time)!

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challenge_74_RP.yxmd

nick_ceneviva

Solution is attached. Was looking forward to seeing how everyone tackled this one but it looks like I took the same approach as most people.

challenge_74_Ceneviva.yxzp

samjohnson

I took a very similar approach using the Generate Rows tool as a number of others, though my use of the tool was slightly different.

Factorial.yxmc

challenge_74_samjohnson.yxmd

dominiklz

Spoiler

first attempt at using macros, seem to have chosen a similar path to most here

challenge_74_Dominik.yxmd

marcreid

Solution

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Macro

challenge_74_MR.yxmd

Factorial_Macro_MR.yxmc

Natasha

Solution

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challenge_74_Natasha.yxmd

challenge_74_Factorial_Macro.yxmc

ggruccio

I knew what I wanted to do but kept losing something in the iteration. Finally decided on a nested macro - which works nicely!

challenge_74_gg_finish.yxzp

LandonG

Solution attached.

challenge_74_start_file.yxzp

samN

Pretty fun

Spoiler

Used a generate rows tool and then did a rolling sum with some filters at the end

Solution attached.

Challenge Completed

Challenge_74_Joe_Serpis.yxzp

SGolnik

I love macros :-)

challenge_74_mysolution.yxmc

CHarrison

As a mathematician, this one pleased me

Challenge 74.yxmd

Ozzy_Campos

Solution Attached. Started trying to make iterative macros embedded in one another, then realized that I had dramatically over-complicated it. Good learning experience.