[chuck-users] CurveTable strange behaviour

[dan trueman]

i agree this is mysterious. the "size" message is a mistake just in  
the fprintf line, so it can be ignored. we're looking at the rest of  
the problem...

dt

On Aug 22, 2007, at 1:24 PM, eduard wrote:

> The following patch shows either a misbehaviour or a misuse of
> CurveTable, dunno. Two different functions
> (rand_coefs1 and rand_coefs2) are used to assign coefficients to
> CurveTable.coefs(). While the first seems to do the job alright, the
> latter
> doesn't and throws the following error message:
> [chuck](via CurveTable): usage:
>    size, time1, value1, curvature1, [ timeN-1, valueN-1,
> curvatureN-1, ] timeN, valueN)
>
> Maybe I'm doing something wrong that | don't see, but can't
> understand why this happens. Could anyone explain?
> Also, don't understand why the error message tells me the size needs
> to be supplied. The examples say that coefs are arrays of the type
> [time1, value1, curvature1, ..., timeN-1, valueN-1, curvatureN-1,
> timeN, valueN] and Gen's size, if I'm not mistaken, is hard coded as
> 4096.
>
> Thanks in advance,
>
> eduard
>
>
> The patch:
>
>
> fun void rand_coefs1( CurveTable table )
> {
>      [-1, 0, 1 ] @=> int curvature[];
>      [0., 0., curvature[ Std.rand2(0, 2)],
>      1, Std.rand2f(.5,1.), curvature[ Std.rand2(0, 2)],
>      2, Std.rand2f(.5,1.), curvature[ Std.rand2(0, 2)],
>      3, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      4, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      5, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      6, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      7, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      8, Std.rand2f(0.,1.), curvature[ Std.rand2(0, 2)],
>      9, 0] @=> float coefs[];
>      coefs => table.coefs;
>
>      <<<"\n", "CURVE 1:\n" >>>;
>      <<<"\t  index", "   value", "   curvature">>>;
>      <<<"\t----------------------------------","\t">>>;
>      for( 0 => int i; i < 8; i++ )
>          <<<"\t",coefs[i++], coefs[i++], coefs[i]>>>;
>      <<<"\t", coefs[8], coefs[9] >>>;
>      <<<"\t----------------------------------","\t">>>;
> }
>
> fun void rand_coefs2( CurveTable table, int n_breakpoints )
> {
>      // this function does not assign values stored in coefs
> correctly to
>      // CurveTable.coefs(). Why? It also throws an error message.
>
>      [-1, 0, 1 ] @=> int curvature[];
>      n_breakpoints*3 - 1 => n_breakpoints;
>      float coefs[ n_breakpoints];
>      0. => coefs[0];
>      0. => coefs[1];
>      for( 2 => int i; i < n_breakpoints; i++ )
>      {
>          curvature[ Std.rand2(0, 2)] => coefs[i++];
>          i/3 => coefs[i++];
>          Std.rand2f(0.,1.) => coefs[i];
>      }
>      0 => coefs[n_breakpoints-1];
>      coefs => table.coefs;
>
>      <<<"\n", "CURVE 2:\n" >>>;
>      <<<"\t  index", "   value", "   curvature">>>;
>      <<<"\t----------------------------------","\t">>>;
>      for( 0 => int i; i < n_breakpoints-2; i++ )
>          <<<"\t", coefs[i++], coefs[i++], coefs[i]>>>;
>      <<< "\t", coefs[n_breakpoints-2], coefs[n_breakpoints-1] >>>;
>      <<<"\t----------------------------------","\t">>>;
> }
>
> CurveTable curve1;
> CurveTable curve2;
> 1024 => int size;
>
> <<< "\n*Assigning coefs via rand_coefs1()","\t">>>;
> rand_coefs1( curve1 );
> 0 => float sum;
> for( 0 => int i; i < size; i++ )
> {
>      curve1.lookup(i) +=> sum;
> }
> if( sum > 0 ) <<<"Ok", "sum[i=0,N=1023] =", sum>>>;
> else <<< "Error:", "sum[i=0,N=1023] =", sum, ". Coefs were not
> assigned. All values are 0." >>>;
>
> <<< "\n*Assigning coefs via rand_coefs2()","\t">>>;
> rand_coefs2( curve2, 10 );
> 0 => sum;
> for( 0 => int i; i < size; i++ )
> {
>      curve2.lookup(i) +=> sum;
> }
> if( sum > 0 ) <<<"Ok", "sum[i=0,N=1023] =", sum>>>;
> else <<< "Error:", "sum[i=0,N=1023] =", sum, ". Coefs were not
> assigned. All values are 0.\n">>>;
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