Is there a bug in MATLAB siderealTime function?

Hey!

I want to use siderealTime function in MATLAB but the value is different in the code below.

I think thGMST(1) and thGMSTfirst are the same also thGMST(end) and thGMSTend are the same too.

But values are different.

How does this occur?

In my computer the values are like this.

thGMSTfirst = 284.3031

thGMSTend = 313.8725

thGMST(1) = 26.2954

thGAST(end) = 55.8647

dates = datetime([2019 1 4 12 0 0]);
dates = dates + days(0:30)';
jdJan = juliandate(dates);
[thGMST, thGAST] = siderealTime(jdJan);

thGMSTfirst = siderealTime(jdJan(1));
thGMSTend = siderealTime(jdJan(end));

Answer 1

[Collin Russo]

Hi Jae-Hee,

Thank you for flagging this issue.

The output of the calls to siderealTime with scalar inputs is correct:

thGMSTfirst = siderealTime(jdJan(1));
thGMSTend = siderealTime(jdJan(end));

There is a bug in the vectorization code for the function - I have created an internal bug report to resolve this issue.

In the meantime, please continue to call siderealTime with scalar inputs. To calculate multiple values, use a for-loop or arrayfun.

In the future, please contact Tech Support if you feel you have found a bug in the software to ensure we are notified as quickly as possible and can address the issue in a timely fashion.

Thanks,

Collin