I tryed to use Cross multiplication and Conjugate roots to factor the transfer function of two-zero feed-forward filter but...I can‘t get the result like :
(1-Z1z^-1)(1-Z2z^-2) on p362.

The name of the book is Designing Audio Effect Plugins in C++
Same function can be found here but no explation about how to factor:https://ccrma.stanford.edu/~jos/filters/Two_Zero.html

@jameslo Thank you soooooo much jameslo!Your patch inspire me a lot!Although it takes me about 2 hours to understand it
I made another version base on your |tableIndexer| idea. And I add |file sample rate/system sample rate| to prevent pitch shift.Well......two things I still don't understand:

• I used |expr $v1<start| in my patch directly but I got message ：receive~ end: vector size mismatch,receive~ start: vector size mismatch.After I deleted |block~ 1 1 1| there was no such message,I'm not sure if they're relevant.

• I notice you use |nrSamples - 2| to valid indexes for 4 point interpolation.But when we apply sinesum function like:|;array1 sinesum 128 1 1|,then there will be 131 samples in array1. So should we add point into it like tabosc4~ help.pd says:'one at the beginning and two at the end, which should be wraparound copies of the last point and the first two points, respectively', but Im confused by tabread4~ help.pd....it did say 'Indices should range from 1 to (size-2)'
  rpole looping scrubber JZ.pd
  rpole looping scrubber JZ.mp4

Looking forward to the reply,have a nice day!

@ddw_music Hi professor!?!? good to see you here! I read your email last week but im so confused with your
patch--varispeed-segment:

|noise~|
|
|lop~ 3|
|
|*~ 30|
|
|+~ 1| |value f1scale|
\ /
|rople~|

You method "L inlet = rate * scale for sample increment",so is the rate always changing?

wow You helped me in class and now you helped me after class. I can't thank you enough，really！！！

Junzhe

@jameslo WOW~amazing！太棒了！Ilike it！this is exactly what I want to create!
I found a little problem ：if sample rate（in audio setting） changed the result sound different in your patch.
and I don't quite understand this part：
|*~ -1e+023|
|
|
|clip~ 0 1|
why times that huge number and then clip？
Would you mind explaining that part?I am really confused;-)

Junzhe hou

Playback rate Phasor~ II.pd
2021-10-22_23-42-55.mp4
Hi,sorry for my bad Enlish.I'm designing a sample player that can play faster or slower then normal speed, play forward and reverse.It is mockup of VCV's NYSTHI-MUSICALBOX plugin. I mainly use |phasor~| and |tabread4~| to calculate the frequency of |phaosr~| by setting the start and end points, and the signal given by |phasor~ is mapped into an index and given to |tabread4~|.
The problem is: when changing the start and end points there will be an obvious audio click, the starting point can be used |samphold~| to do the logic to take effect the next time you play, but the audio click that occurs when changing the end point really do not know how to do.

Translated with www.DeepL.com/Translator (free version)