# Feature Request: Add Log10 (Logarithm Base 10) function to textfields

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I was recently shown: https://affinity.help/designer/English.lproj/pages/Workspace/expressions.html

However, the function I need (Log10) is missing.

Also, is it possible to use multiple functions in a single text field? I have need to specify a number between a range of positive real numbers into a formula like this:

(360.0 * log10(sin(number that can vary between 0 and 1)))

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2 minutes ago, GreenGirl said:

Also﻿, is it possible to use multiple functions in a single text field? I have need to specify a number between a range of positive real﻿ numbers﻿ into a for﻿mula like this:

﻿ (360.0 * log10(sin(number that can vary b﻿etween 0 and﻿ ﻿1)))﻿﻿

Yes, you can do that (but obviously not with log10 at the moment).

Alfred
Affinity Designer/Photo/Publisher 1.7.1.404 • Windows 10 Home (4th gen Core i3 CPU)

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To convert from natural logs to logs base 10, just multiply by 0.434294481903252 (log10(exp(1)).

You can easily include this constant in your expressions.

John

Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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5 hours ago, John Rostron said:

You can easily include this constant in your expressions.

Easily?

I don't think I've ever seen a 14 decimal-place constant called easy

-- Walt

Windows 10 Home, version 1903 (18362.239), 16GB memory, Intel Core i7-6700K @ 4.00Gz, GeForce GTX 970
Affinity Photo 1.7.2.471 and 1.7.2.464 Beta   / Affinity Designer 1.7.2.471 and 1.7.2.4464 Beta  / Affinity Publisher 1.7.2.471 and 1.7.2.458 Beta

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2 hours ago, walt.farrell said:

Easily?

I don't think I've ever seen a 14 decimal-place constant called easy

Well there is easy and then there is accurate... In my head pi used to have 6 decimal places, now it only has 2.

MacBook Pro (13-inch, Mid 2012) Mac OS 10.12.6 || Mac Pro (Late 2013) Mac OS 10.14.5

Affinity Designer 1.7.2 | Affinity Photo 1.7.2 | Affinity Publisher 1.7.2 | Affinity Designer Beta 1.7.2.2 | Affinity Photo Beta 1.7.2.151 | Affinity Publisher Beta 1.7.2.458

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14 hours ago, walt.farrell said:

Easily?

I don't think I've ever seen a 14 decimal-place constant called easy

You can copy and paste a 14 decimal place constant just as easily as a 2 decimal place one.

John

Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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12 hours ago, Old Bruce said:

Well there is easy and then there is accurate... In m﻿﻿﻿﻿﻿﻿﻿﻿y﻿﻿ head﻿ pi used to h﻿ave 6 decimal places, now it onl﻿y h﻿as 2.﻿﻿

I’m shocked to discover that you don’t remember it to twenty decimal places (3.14159265358979323846) as I do!

Alfred
Affinity Designer/Photo/Publisher 1.7.1.404 • Windows 10 Home (4th gen Core i3 CPU)

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19 hours ago, Alfred said:

I’m shocked to discover that you don’t remember it to twenty decimal places (3.14159265358979323846) as I do!

Do you guys here seen the British guy that can Pi with more than 21000 decimals?

T

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On 7/19/2019 at 12:52 PM, Alfred said:

I’m shocked to discover that you don’t remember it to twenty decimal places (3.14159265358979323846) as I do!

I do recall there was a mnemonic for the decimal digits of pi that began "How I wish I could ..." I recall that Archimedes" featured somewhere for 9.

John

Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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1 hour ago, John Rostron said:

I do recall there was a mnemonic for the decimal digits of pi that began "How I wish I could ..." I recall that Archimedes" featured somewhere for 9.

That rings a vague bell, John. The mnemonic I know is

Quote

Sir, I bear a rhyme excelling﻿﻿﻿﻿,﻿﻿﻿﻿﻿﻿
﻿In mystic force and magic spelling.
Celestial sprites elucidate﻿﻿﻿﻿,﻿﻿﻿﻿﻿﻿
All my own striving can’t relate.

One nice touch is that it even includes a comma for the decimal separator after ‘Sir’ (3). I find it almost as easy to remember a string of twenty digits, which has the advantage that you don’t need to do any counting, but it’s good to have a mnemonic to fall back on if you get lost somewhere along the way!

Alfred
Affinity Designer/Photo/Publisher 1.7.1.404 • Windows 10 Home (4th gen Core i3 CPU)

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5 hours ago, John Rostron said:

I﻿ r﻿ecall that Archimedes" featured somewhere for 9.﻿﻿

I’ve just re-read this and spotted a slight problem: “Archimedes” has 10 letters!

Edit: Found it!

Quote

How I wish I could recollect, of circle round, the exact relation Arkimedes (or Archimede) learned

Alfred
Affinity Designer/Photo/Publisher 1.7.1.404 • Windows 10 Home (4th gen Core i3 CPU)

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4 minutes ago, Alfred said:

I’ve just re-read this and spotted a slight problem: “Archimedes” has 10 letters!

I told you that it was what I recalled. I did not say my recollection was accurate. I met this mnemonic at school, probably over sixty years ago!

John

Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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13 minutes ago, Alfred said:
16 minutes ago, Alfred said:

How﻿ I wish﻿﻿﻿ I could recollect, of circle round﻿, the exact relation Arkimedes﻿ (or Archimede﻿) learned

I think that a mnemonic that relies on a variant spelling is of less than optimal utility.

John

Windows 10, Affinity Photo 1.7 and Designer 1.7, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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7 minutes ago, John Rostron said:

I think that a mnemonic that relies on a variant spelling is of less than optimal utility.

As clearly demonstrated by the fact that you couldn’t recall it accurately a mere sixty years later.

Alfred
Affinity Designer/Photo/Publisher 1.7.1.404 • Windows 10 Home (4th gen Core i3 CPU)

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If anyone is *that* bored and needs something to do, here are the first million digits of pi: https://www.piday.org/million/

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