Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.

## geekIT

633 posts

Ultimate Geek

Topic # 191123 24-Jan-2016 17:23

Hi folks. The following formula has two frequently changing variables, the '84' and '75' values.

Does anyone know of a way I could automate a solution to this equation, so that I don't have to do the whole 9-yard calculation every time?

For example, '84' will probably soon become '81' and '75' will go to '76'.

Perhaps there's a small app that'll work it?

Equation:
[66.47 + (13.75 x 84) + (5 x 175 ) - (6.76 x 75] x 1.375 =

 1 | 2 Next

## gregmcc

1511 posts

Uber Geek

5 people support this post

put it in an excel spreadsheet, with the values that change referencing cells that you edit

## StarBlazer

943 posts

Ultimate Geek

Trusted
Subscriber

One person supports this post

Can you not just use a spreadsheet? Put the variable values in cells and the calculation in the 3rd cell.

Procrastination eventually pays off.

## doug3

79 posts

Master Geek

Subscriber

A good iOS app to do this is Calcility - Redefine Calculator (Lite) by JIAN FEI XU
https://appsto.re/nz/REKMM.i
It has a history section with folders and you can annotate the individual expression so you can quickly find and reuse the expression.
There is no need for all the brackets
(66.47 + 13.74 x 84 + 5 x 175 - 16.76 x 75) x 1.375 will give the same result.

## toyonut

1507 posts

Uber Geek

#Set our variables
\$var1 = Read-Host "What is variable 1?"
\$var2 = Read-Host "What is variable 2?"
#write the formula out to show the variables are correct
Write-Output "Formula = (66.47 + (13.75 * \$var2) + (5 * 175 ) - (6.76 * \$var1) * 1.375)"
\$ans = (66.47 + (13.75 * \$var2) + (5 * 175 ) - (6.76 * \$var1) * 1.375)
#Write the output of the \$ans variable into the console.

Save that a PowerShell script then when you need it, call it up with .Directory\scriptname.ps1.

You would need to have run set-executionpolicy remotesigned at some point, else it won't run the script.

Not really serious, just a fun exercise.

*Edit* Used tab complete to set case correctly in script

Try Vultr using this link and get us both some credit:

http://www.vultr.com/?ref=7033587-3B

## gzt

9481 posts

Uber Geek

And that marks the first time I have seen a powershell script posted on geekzone. : ).

## bazzer

3277 posts

Uber Geek

Trusted

One person supports this post

Unless I misunderstand, your equation can be simplified to 18.90625 x [84] - 9.295 x [75] + 1294.52125 = 2185.52125

Just change the numbers in square brackets and you're all good. Relies on the distributive property of multiplication.

## geekIT

633 posts

Ultimate Geek

Guys, thanks for your responses, but I'm still stuck here at the bakehouse, duh. (1953 School Cert Maths = 51%)

gregmcc and StarBlazer: I'm sure your suggestions were very sensible but I've never been able to get to grips with Excel. I do have it, so if some one could post an .xls (2003) file I'd give it a try.

doug3: As far as I could see, I couldn't get the calculator without signing up for either Apple or Facebook, neither of which I'm interested in. But I think the app might be a little abstruse for me, anyway. Sorry :-(

toyonut: Like the calculator, scripting is kinda above my paygrade. Sorry :-(

bazzer: Thanks for the simplification (also doug3 for that). I wasn't aware an expression like that could be re-stated like that. If nothing else comes along (like a Cortana-ish robot for Windows 7 that asks me in a polite but seductive voice to state my variables), I'll use that method.

## ObidiahSlope

165 posts

Master Geek

gzt: And that marks the first time I have seen a powershell script posted on geekzone. : ).

Yay for PowerShell, powerful and versatile. Capable in its own right and with hooks into the dotnet libraries.

## gregmcc

1511 posts

Uber Geek

1st Variable number

84

2nd Variable number

75

1399.345

=SUM(66.47+(13.75*A2)+(5*175)-(6.76*A4)*1.375)

This is the formula that goes in the box below "Answer"

## Jase2985

7267 posts

Uber Geek

Subscriber

throw the formula into cell A1, substitute 84 for B1 and 75 for C1. throw 84 into cell B1 and throw 75 into cell C1. if you need to change it change the numbers in cells B1 and C1

Edit: pretty much what greg said except I went across

## ObidiahSlope

165 posts

Master Geek

Write-Output "Formula = (66.47 + (13.75 * \$var2) + (5 * 175 ) - (6.76 * \$var1) * 1.375)"

I have reworked the line above using Write-Host and its -NoNewline and -ForegroundColor arguments together with the semicolon command seperator to highlight the variable values.

Write-Host -NoNewline "Formula = (66.47 + (13.75 * "; Write-Host -NoNewline -ForegroundColor yellow "\$var2"; Write-Host -NoNewline ") + (5 * 175 ) - (6.76 * "; Write-Host -NoNewline -ForegroundColor yellow "\$var1"; Write-Host ") * 1.375)"

## Ouranos

117 posts

Master Geek

gregmcc: 1st Variable number 84 2nd Variable number 75 Answer

1399.345

=SUM(66.47+(13.75*A2)+(5*175)-(6.76*A4)*1.375)

This is the formula that goes in the box below "Answer"

That spreadsheet formula has two, or possibly three, errors:

1. The SUM function is unnecessary. Effectively it says =SUM(x) which is just x. I see many people do this and I don't understood why.

2. A formula should never contain hard-coded "magic numbers". For example, what does 66.47 mean? Put each of the numbers in a cell and refer to them. Then document what each of the numbers means, where it comes from, etc.

3. The OP stated the equation as "[66.47 + (13.75 x 84) + (5 x 175 ) - (6.76 x 75] x 1.375" which has mismatched parentheses. Looking at the square brackets, I assume it is intended that the whole thing is multiplied by 1.375. If so, then =SUM(66.47+(13.75*A2)+(5*175)-(6.76*A4)*1.375) is wrong (as is the PowerShell script posted earlier). That is, does the original equation equal 2185.52125 or 1399.345?

## geekIT

633 posts

Ultimate Geek

Uh..does anyone know of a forum called DorkZone? 'Cos I think I should've posted my question there.

Think I'll just have a lie-down until my eyeballs stop spinning...

Oh, but thanks for all those erudite responses :-)

## Dolts

156 posts

Master Geek

Subscriber

Ouranos:

gregmcc: 1st Variable number 84 2nd Variable number 75 Answer

1399.345

=SUM(66.47+(13.75*A2)+(5*175)-(6.76*A4)*1.375)

This is the formula that goes in the box below "Answer"

That spreadsheet formula has two, or possibly three, errors:

1. The SUM function is unnecessary. Effectively it says =SUM(x) which is just x. I see many people do this and I don't understood why.

2. A formula should never contain hard-coded "magic numbers". For example, what does 66.47 mean? Put each of the numbers in a cell and refer to them. Then document what each of the numbers means, where it comes from, etc.

3. The OP stated the equation as "[66.47 + (13.75 x 84) + (5 x 175 ) - (6.76 x 75] x 1.375" which has mismatched parentheses. Looking at the square brackets, I assume it is intended that the whole thing is multiplied by 1.375. If so, then =SUM(66.47+(13.75*A2)+(5*175)-(6.76*A4)*1.375) is wrong (as is the PowerShell script posted earlier). That is, does the original equation equal 2185.52125 or 1399.345?

If you can state if 2185.52125 or 1399.345 is the correct answer that you need, I have written a small app that gives the answer 1399.345

## gzt

9481 posts

Uber Geek

geekIT: Does anyone know of a way I could automate a solution to this equation, so that I don't have to do the whole 9-yard calculation every time?

Do you have a gmail account? This could be set easily by someone here as a form to input data from a web page.

 1 | 2 Next

News »

Stuff Pix enters streaming video market
Posted 21-Mar-2018 09:18

Windows no longer Microsoftâ€™s main focus
Posted 13-Mar-2018 07:47

Why phone makers are obsessed with cameras
Posted 11-Mar-2018 12:25

New Zealand Adopts International Open Data Charter
Posted 3-Mar-2018 12:48

Shipments tumble as NZ phone upgrades slow
Posted 2-Mar-2018 11:48

Oppo R11s: high-end Android, budget price
Posted 27-Feb-2018 16:27

Samsung New Zealand introducing the Galaxy S9 and S9+
Posted 26-Feb-2018 07:00

Fujifilm X beats its best with new top of the range, high-performance camera
Posted 24-Feb-2018 14:05

One million kiwis affected by cybercrime
Posted 24-Feb-2018 13:58

New Zealanders want to engage with government online and via mobile apps
Posted 24-Feb-2018 13:56

Samsung launches Samsung Max
Posted 24-Feb-2018 13:52

CPTPP text and National Interest Analysis released for public scrutiny
Posted 21-Feb-2018 19:43

Foodstuffs to trial digitised shopping trolleys
Posted 21-Feb-2018 18:27

2018: The year of zero-login, smart cars & the biometrics of things
Posted 21-Feb-2018 18:25

Intel reimagines data centre storage with new 3D NAND SSDs
Posted 16-Feb-2018 15:21

Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.