Thank you for providing the excellent package and documents for analytical continuation. I am new to DQMC and analytical continuation, and I have noticed that there is a mix-up in the terminology used in the codes regarding ”standard deviation“ and ”error“. This has caused confusion for me, particularly when it comes to the input "standard deviation" for ACFlow. I would like to clarify whether it should be the actual standard deviation $\sigma=\sqrt{\frac{\sum_{i=1}^n \left(x_i-\bar{x}\right)^2}{n}}$, or the standard error $\sigma_n=\frac{\sigma}{\sqrt{n}}$ (where $n$ represents the number of samples). For my data, the standard deviations maybe large while standard errors are smaller. And I am afraid that standard deviations are too noisy.

First off, ACFlow is looking great so far. Great work!

I am looking to incorporate ACFlow into an in-house Julia DQMC project which is in development. Because everything will be in Julia we have no need for the default ACFlow file output. Could you add a variable to disable file output? I think adding it in the [BASE] section of the toml (or in our case B dictionary) would probably be the easiest way to handle it without making the code any more complicated for the non-Julia users.

Thanks,
James Neuhaus
Steve Johnston Group

When running ACFlow (current master branch) the stochastic optimization method for symmetric time kernels I am getting NaN for the delta. Below is the output.

I've attached an example script with input data. I also run MaxEnt which converges well.

Thanks.

[ StochOM ]
Create infrastructure for Monte Carlo sampling
Postprocess input data: 201 points
Build grid for input data: 201 points
Build mesh for spectrum: 1000 points
try ->      1 (    25) Δ ->      NaN 
try ->      2 (    25) Δ ->      NaN 
try ->      3 (    25) Δ ->      NaN 
try ->      4 (    25) Δ ->      NaN 
try ->      5 (    25) Δ ->      NaN 
try ->      6 (    25) Δ ->      NaN 
try ->      7 (    25) Δ ->      NaN 
try ->      8 (    25) Δ ->      NaN 
try ->      9 (    25) Δ ->      NaN 
try ->     10 (    25) Δ ->      NaN 
try ->     11 (    25) Δ ->      NaN 
try ->     12 (    25) Δ ->      NaN 
try ->     13 (    25) Δ ->      NaN 
try ->     14 (    25) Δ ->      NaN 
try ->     15 (    25) Δ ->      NaN 
try ->     16 (    25) Δ ->      NaN 
try ->     17 (    25) Δ ->      NaN 
try ->     18 (    25) Δ ->      NaN 
try ->     19 (    25) Δ ->      NaN 
try ->     20 (    25) Δ ->      NaN 
try ->     21 (    25) Δ ->      NaN 
try ->     22 (    25) Δ ->      NaN 
try ->     23 (    25) Δ ->      NaN 
try ->     24 (    25) Δ ->      NaN 
try ->     25 (    25) Δ ->      NaN 
Median χ² :              NaN Accepted configurations :     0

som_check.zip