### Failed to determine covariance matrix in uvfit

Posted:

**Fri May 31, 2019 12:05 pm**Hi,

From my previous post I'm attempting to measure the flux of my target with uvfit.

Upon the previous suggestion to implement: uvfit vis=myvis line=chan,200,1,10,10 object=point

I receive the following errors:

uvfit: Revision 1.10, 2013/08/30 01:49:21 UTC

Reading the data ...

Applying bandpass corrections to hd100453.33000

Applying gain corrections to hd100453.33000

### Warning: Performing linetype averaging before applying bandpass!!

### Warning: ... this may be very unwise

Total number of correlations: 16472030

Performing the fitting process ...

### Warning: Failed to determine covariance matrix

------------------------------------------------

RMS residual is 6.648E-02

Source 1, Object type: point

Flux: 0.000

Offset Position (arcsec): 0.0000 0.0000

------------------------------------------------

I'm unsure why I'm receiving the bandpass error even though the uvfit task prints the bandpass solution is being applied and more importantly, I'm unsure why determining the covariance matrix fails and I receive a zero flux reading.

Any suggestions would be greatly appreciated.

Thanks,

Brodie

From my previous post I'm attempting to measure the flux of my target with uvfit.

Upon the previous suggestion to implement: uvfit vis=myvis line=chan,200,1,10,10 object=point

I receive the following errors:

uvfit: Revision 1.10, 2013/08/30 01:49:21 UTC

Reading the data ...

Applying bandpass corrections to hd100453.33000

Applying gain corrections to hd100453.33000

### Warning: Performing linetype averaging before applying bandpass!!

### Warning: ... this may be very unwise

Total number of correlations: 16472030

Performing the fitting process ...

### Warning: Failed to determine covariance matrix

------------------------------------------------

RMS residual is 6.648E-02

Source 1, Object type: point

Flux: 0.000

Offset Position (arcsec): 0.0000 0.0000

------------------------------------------------

I'm unsure why I'm receiving the bandpass error even though the uvfit task prints the bandpass solution is being applied and more importantly, I'm unsure why determining the covariance matrix fails and I receive a zero flux reading.

Any suggestions would be greatly appreciated.

Thanks,

Brodie