MATLAB Answers

Add n days to juliandate

3 views (last 30 days)
Hello everyone!
I am using
planetEphemeris(juliandate(y, m, d), 'Sun', 'Mars')
to extract the position of Mars relative to Sun at a given date
y, m, d.
Now, I need to add a specific number of days to that date and extract the position of the new date. Apparently,
planetEphemeris(juliandate(y, m, d) + n, 'Sun', 'Mars')
does not work. What do I need to add instead of n to have the position of Mars in, say, 100 days after that date?
Thank you in advance.

  0 Comments

Sign in to comment.

Accepted Answer

Robert U
Robert U on 23 Jan 2020
Hi Asatur Khurshdyan,
According to documentation example juliandate() you may use caldays() to add calendar days to a datetime-date.
planetEphemeris(juliandate(datetime(y,m,d)+caldays(n)), 'Sun', 'Mars')
Kind regards,
Robert

  1 Comment

Asatur Khurshudyan
Asatur Khurshudyan on 23 Jan 2020
Dear Robert,
Thank you for your answer. Sorry about missing that part from documentation.
Best,
Asatur

Sign in to comment.

More Answers (1)

Bjorn Gustavsson
Bjorn Gustavsson on 23 Jan 2020
It seems to work just fine as far as I can see. When I compare:
jd0 = juliandate(2020, 2, 14);
jd0p100 =juliandate(2020, 2, 14) + 100;
jd0p101 =juliandate(2020, 2, 14 + 100);
isequal(jd0p100,jd0p101) % returns true
jd0p101 - jd0 % returns 100
everything seems OK.
What is your problem? What matlab-version are you using?
HTH

  0 Comments

Sign in to comment.