how does remap number work if i do not enter sourse domain

if i use sourse domain for" remap number", i can understand the relationship between input and output.

but if i do not use sourse domain, i can not understand how it works.

seems the distance between numbers has been scaled to the distance of target input(1.1 to 2.1 is 1, 3.07 to 4.77 is 1.7 )

but how does the first output number 3.07 come from?

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Replies to This Discussion

Permalink Reply by Danny Boyes on July 13, 2012 at 3:00am

There is a default of 0 to 1

Permalink Reply by Jissi Choi on July 13, 2012 at 3:16am

Let Source Domain as S1 to S2 and Target Domain as T1 to T2..

If X is a value of input, the output value, Y, is..

( Y - T1 ) / ( T2 - T1 ) = ( X - S1 ) / ( S2 - S1 )

----

In your example..

T2 - T1 = 2.9 - 1.2 = 1.7

S2 - S1 = 1.0 - 0.0 = 1.0

(T2-T1)/(S2-S1) = 1.7 / 1.0 = 1.7 (called scale factor)

Y = 1.2 + 1.1 * 1.7 = 3.07

Permalink Reply by Dedackelzucht on July 13, 2012 at 3:29am

good explanation!

Permalink Reply by Sumeet Kumar on July 14, 2014 at 3:51pm

Hi I am new to Grasshopper. I want to know why forcibly going for this linear equation " for remapping numbers. ( Y - T1 ) / ( T2 - T1 ) = ( X - S1 ) / ( S2 - S1 )". Does it means every one is using same equation. I think with certain combination of components, we can have our own equation. Do we really need such component. Might be I haven't explored its potential yet. Correct me if I am wrong.

Permalink Reply by Danny Boyes on July 14, 2014 at 5:12pm