ui.R

# Let user put in latitude, longitude, time zone longitude,
# time of day, and day of year
# then use Angstrom equation to estimate Rs from Ra and convert to PAR

shinyUI(fluidPage(
  
  tags$head(includeHTML((
    "google_analytics.html"
  ))),
  
  # Application title
  titlePanel("PPFD and DLI by time, day, latitude, and longitude."),
  ## withMathJax(),
  HTML(paste("See more about light and photosynthetically active radiation (PAR) on the ",
          a("ATC website",
            href = "https://www.asianturfgrass.com/tag/light/"),
          ".",
          sep = "")),

  # Sidebar to input necessary data
  
  verticalLayout(
   
      dateInput("date", "Date:"),
      
      numericInput("hour", "Hour", lubridate::hour(lubridate::now()),
                   0, 23, 1),
      
      numericInput("minute", "Minute", lubridate::minute(lubridate::now()),
                   0, 59, 1),

      numericInput("latitude",
                  "Latitude in degrees N (positive values) or S (negative values) of the equator",
                  min = -66.6,
                  max = 66.6,
                  value = 13.4,
                  step = 0.01),
      
      numericInput("Lm",
                   "Longitude degrees E (positive values) or W (negative values) of Greenwich",
                   min = -179.99,
                   max = 179.99,
                   value = 100.5,
                   step = 0.01),
      
      # numericInput("Lz",
      #              "Longitude at center of time zone, degrees W of Greenwich",
      #              min = 0,
      #              max = 359.99,
      #              value = 255,
      #              step = 0.01),
      
      numericInput("ab", "Transmittance, recommended 0.75 for clear sky conditions",
                              0.75, min = 0, max = 1, step = 0.01),
      
    # Show the output
   
      h3(textOutput("text1")),
    
    # explain what this is
    hr(),
    helpText(HTML(paste("PPFD is photosynthetic photon flux density in units of µmol photons m",
                   tags$sup("-2"), " s", tags$sup("-1"), " and DLI
                   is daily light integral in units of mol m",
                    tags$sup("-2"), " d", tags$sup("-1"), ".", sep = ""))),
    
    helpText(HTML(paste("This app calculates the PPFD and DLI for any location between 66° N and 66° S using the Ångström equation."))),
    
    helpText(HTML(paste("One way to find the exact latitude and longitude for any location is to click on a point in Google Maps. The first number shown is the latitude of that point, and the second number is the longitude."))),
    
      helpText(HTML(paste("For more information about this calculator, 
                    bug reports, and feature requests, see the code on ",
                        a("GitHub.",
                          href = "https://github.com/micahwoods/ppfd_by_time"),
                        " You can find PAR, light, and shade information at the PACE Turf and ATC websites. This is version 0.1.4 of the ",
                        code("ppfd_by_time"),
                        " app, last updated by Micah Woods on 2024-06-30.",
                        sep = ""))),
    br(),
    a(href = "https://www.paceturf.org", 
      img(src = "pace.png", width = 300, height = 41)),
    br(),
    a(href = "https://www.asianturfgrass.com", 
      img(src = "atc_logo_no_white.png", height = 137, width = 300)),
    br()
      
    )
  )
)