The Kyma Language for Sound Design, Version 4.5

Scale and Offset
90% of all arithmetic that you will need in parameter fields will fit the same basic pattern. Most of the
time, we want to change the range of a fader to be something other than 0 to 1. So most of our expressions
will look something like this:
!Fader * range + minimum
To change the range of a fader that goes from 0 to 1, multiply it by the range you really want. For example,
if you want your frequencies to have a range of one octave, you could multiply (or scale) the
!Frequency fader by 12 half steps:
!Frequency * 12 nn
That would give you a range of note numbers from 0 to 12. Note number 0 is pretty low, so you probably
would want to give it a different minimum note number. To set the minimum, you could add to (or
offset) your value:
!Frequency * 12 nn + 60 nn
Now your !Frequency fader covers the range from middle C (note number 60) to one octave higher
(note number 72).
Sometimes multiplying is called scaling, because it retains the shape of the function, and just scales its
size:
⇒
And sometimes adding a constant number is called adding an “offset”, because it doesn’t change the
shape or the size of the function, it just shifts the whole thing up or down — setting it off from the original
axis. You may have encountered this terminology before in the form of “DC offset”, when some
constant voltage is added to your audio signal, shifting it up or down with respect to zero.
⇒
In some of the Kyma documentation and nomenclature, you will see the words, scale, offset or
ScaleAndOffset to mean multiply and add.
Minus 1
One version of the scale and offset that comes up fairly often in Kyma is the one that takes you from the
range of (0,1) to the range (-1,1). Since the range of a Sound’s output is typically (-1,1) and the
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