This is somewhat related to timestretching a interpolation, I read previous posts on similar topics and looked into the patches, but found no working solution.
I have a table with a few coefficients, say 12, from a FIR impulse response. I want to slightly stretch them to make them 14 or 20 or so, and keep the shape of the impulse response.

I tried [trabread] with a [line] as input, linear interpolate between two table numbers and then writing them to a new table with [tabwrite] with the same [line] object output multiplied by the rate for stretching, say 1.2, but I get ugly results.

Any suggestions, or patches in the PD browser?
Thanks

Leopard

basically that is the way i'd do it too. you have to make sure that you feed tabwrite with integer index numbers together with the corresponding values. tabread isn't doing any interpolation between values though. maybe you might want to try using tabread4.
if you don't get it to work just post the patch so it becomes a bit clearer what you mean by "ugly results".

the other option would be to send the number of the samples in the stretched table into [until], connect that to a counter (kind of like in the [until] helpfile) and use that as tabwrite index. to read the interpolated values for these indexnumbers from the old array you have to scale those indexnumbers by the stretchfactor before you go into tabread4.

Thanks ralf. This attached is a patch to make my trouble clearer.
Cheers

http://www.pdpatchrepo.info/hurleur/stretch_forum.pd

One problem is that you're not properly scaling the read/write indices. Your original array is only 14 points, so counting up to 24 is going beyond the bounds of the array. If you were to do it with [line] (which I don't recommend), you should just have [line] count from 0 to 1 and multiply that by the array sizes for the read and write indices. However, you'll still end up with ugly results, because [line] is just sending a stream of numbers. So you'll get multiple interpolated reads, and they won't line up right.

ralf's suggestion of using [until] is a lot better. If you're writing to a 12-point array, then you only want to calculate those 12 points ([line] doesn't output a set number of values). So you have [until] count up to the maximum index of your write table, and rescale those values to the size of your read table. Those values will be set to the exact point of interpolation that you're looking for. I've attached an example that will hopefully make it clearer.

http://www.pdpatchrepo.info/hurleur/FIR-resize.mmb.pd

Thanks for the patch and the clear explanation.
Here's attached what I wanted to do. I'll implement it in a digital wavelet patch, which I hopefully share soon.
Cheers

http://www.pdpatchrepo.info/hurleur/FIR-resize.mmb.leo.pd