So I'm writing a little program to generate a pitch sweepable sine wave. It's easy enough to make it linear. I have a seekbar with values from 20hz to 20khz, but I want to make it a log scale and I'm completely lost. What's the equation to find the next interval (up or down) from a given frequency. Or maybe, a better question, is how do convert and arbitrary linear scale to a log scale relevant to frequency? My brain is now boogaloo

The logarithm represents the exponent that 10 is raised to. That is, 100 = 10 to the power of 2, therefore log 100 = 2. Similarly, 1000 = 10^3 so log 1000 = 3. You would have an exponential function f(x) := 2*10^x If you take values of x from 1 to 4 you'd get the familiar 20-20kHz sweep. f(1) = 2*10^1 = 20 Hz f(2) = 2*10^2 = 200 Hz f(3) = 2*10^3 = 2 kHz f(4) = 2*10^4 = 20 kHz Rather than sweeping from 20 to 20 000 by a step of 1, you would sweep from 1 to 4 with a step of 0.01 (or whatever values are appropriate for the rate of change). I hope that's of some use!

thats what i needed. that really helps it was very hard to find this information distilled like that. you are an absolute gent.