[AstroPy] How to plot a time format with hours only?

[Eric Jensen]

Hi Ramiro, 

I think you should be able to get just the hour of the rise or set time by using 

star_rise_time.ymdhms.hour

If you want other components as well, you can use .year, .minute, etc. with that ymdhms format. 

Hope this helps - 

Eric
 

> On Apr 23, 2021, at 5:44 AM, Miro Saide <mirosaide at gmail.com> wrote:
> 
> Hello all,
> 
> I am using the following code to plot the rise and set of a particular star from a selected location on earth:
> 
> import numpy as np
> import matplotlib.pyplot as plt
> from astropy.visualization import astropy_mpl_style, quantity_support
> plt.style.use(astropy_mpl_style)
> quantity_support()
> import astropy.units as u
> from astropy.time import Time
> from astropy.coordinates import SkyCoord, EarthLocation, AltAz
> from astroplan import download_IERS_A
> download_IERS_A
> from astroplan import Observer, FixedTarget
> 
> #Latitude and LOngitude of some cities
> cities = [[-25.9553,32.5892],[-25.7069,28.2294],[-15.4166,28.2833],[-22.95764,18.49041],[-13.254308,34.301525]]
> cities = np.array(cities)
> 
> time = Time("2000-11-12 11:00:00",format='iso')
> 
> #Star target
> target = SkyCoord.from_name("Barnard's star")
> 
> 
> #Calculation of the rise and set time 
> Location = Observer(latitude=cities[:,0]*u.deg, longitude=cities[:,1]*u.deg)
> star_rise_time = Location.target_rise_time(time, target, which='next')
> star_set_time = Location.target_set_time(time, target, which='next')
> 
> #Get the time in iso format
> rise_1 = star_rise_time.iso
> set_1 = star_set_time.iso
> 
> 
> #Random values
> Random_valeus = [1600,2118,3000,2750,3500]
> 
> 
> #Plot the time against random values
> 
> plt.plot(rise_1,Random_valeus, marker ='o',label = 'rise')
> plt.plot(set_1,Random_valeus, marker ='o',label = 'set')
> plt.xlabel('Time [Hours]')
> plt.ylabel('Random_valeus')
> plt.show()
> 
> When I run this the time axis in the plot gets messy the values overlap and can't clearly see what is what.
> 
> I wonder if there's is a way to plot this with hours only, neglecting the year, month, day, minutes, and seconds?
> 
> Thanks in advance.
> 
> Ramiro Caisse Saide
> MPhil Research Student
> Department of Physics
> University of Mauritius
> Contact Number: +258 845672884
> Email: ramiro.saide at umail.uom.mu <mailto:ramiro.saide at umail.uom.mu>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.python.org/pipermail/astropy/attachments/20210423/87a5a553/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4388 bytes
Desc: not available
URL: <https://mail.python.org/pipermail/astropy/attachments/20210423/87a5a553/attachment.bin>