What is the vScale of a SINGFUN? about chebfun

[davidagross]

Hi everyone! Long time no see.

While I've been watching your work much less closely than I used to, the closure here did come across my inbox as a bit of a surprise. Going back into #1026 we can see that vscales are still not the same for f1, f2, and f3 as defined here:

>> f1 = chebfun(@(t) t.^0.5./exp(t), [0,inf], 'exps', [0.5 0])
>> f2 = chebfun(@(t) t.^0.5./exp(t), [0,1,inf], 'exps', [0.5 0 0 0])
>> f3 = f1; f3(1) = f3(1)
>> table([sum(f1); sum(f2); sum(f3)],[max(f1); max(f2); max(f3)],[f1.vscale;f2.vscale;f3.vscale],'VariableNames',{'sums','maxes','vscales'})

f1 =

   chebfun column (1 smooth piece)
       interval       length     endpoint values   endpoint exponents
[       0,     Inf]       44         0   -1e-15         [0.5      0]  
vertical scale = 2.7 


f2 =

   chebfun column (2 smooth pieces)
       interval       length     endpoint values   endpoint exponents
[       0,       1]       13         0     0.37         [0.5      0]  
[       1,     Inf]       61      0.37 -4.6e-16         [0      0]  
vertical scale = 0.71    Total length = 74


f3 =

   chebfun column (2 smooth pieces)
       interval       length     endpoint values   endpoint exponents
[       0,       1]       11         0     0.37         [0.5      0]  
[       1,     Inf]       60      0.37 -9.6e-16         [0      0]  
vertical scale = 0.71    Total length = 71


ans =

  3×3 table

          sums                 maxes               vscales     
    _________________    _________________    _________________

    0.886226925452756    0.428881942480354     2.73861278752584
    0.886226925452754    0.428881942480353    0.707106781186547
    0.886226925452759    0.428881942480349    0.707106781186632

While the sum (has been fixed and) is correct, the vertical scales are still quite off (by factors of almost 2 or 6 pretty much).

I'm just chiming in to make sure that this issue is still sufficiently tracked in, say, #1633 (even though a vscale discrepancy isn't actually documented there in this detail).

Thanks, and hope you all are doing well!