analemma

analemma(; lon=0, lat=0, hour=12, year=2024, lonlat=false, data=false, cmap=:turbo, kwargs...)

Plot the analemma.

The analemma is the figure-8 pattern traced by the Sun’s position in the sky when observed from the same location at the same mean solar time throughout the year.

Arguments

  • lon : Observer longitude in degrees.

  • lat : Observer latitude in degrees. If both lon and lat are equal to zero (the default) we compute your approximate location using web service based your IP address (this adds a delay to the calculations).

  • year : Year for calculation (default: 2026). This is of minor importance but things slowly change with time.

  • hour : Local mean solar time hour (0-24, default: 12 = noon)

  • cmap : Colormap for day-of-year coloring (default: :turbo)

  • lonlat=false: If true, plot longitude vs latitude; if false (default), plot azimuth vs elevation.

  • data=false: If true, return the CO2 data in a GMTdataset.

  • Additional kwargs are passed to plot

Examples

analemma(lon=-9, lat=38.7)     # Noon analemma in Lisbon
analemma(lat=-23.5, hour=9)    # 9 AM analemma in tropics

D = analemma(lon=-9, lat=38.7, lonlat=true, data=true)   # Get analemma in lon,lat as a GMTdataset

Returns

A Vector of GMTdataset containing the projected meridians and parallels. grat[i] attributes store information about that element lon,lat.

Source Code

View the source code for this function.

See Also

solar