Kotlin connector to the Meteomatics API
===================================================================================
Meteomatics provides a REST-style API to retrieve historic, current, and forecast data globally. This includes model data and observational data in time series and areal formats. Areal formats are also offered through a WMS/WFS-compatible interface. Geographic and time series data can be combined in certain file formats, such as NetCDF.
You can install the development version of Meteomatics Kotlin Connector from GitHub by cloning the git repository to a local directory of your choice; then the downloaded functions can be used.
The following external Kotlin packages are required and need to be imported inside the project:
com.example.newkotlinconnector, android.os.Bundle, android.util.Log, androidx.appcompat.app.AppCompatActivity, androidx.lifecycle.lifecycleScope, com.example.newkotlinconnector.databinding.ActivityMainBinding, com.facebook.stetho.Stetho, java.time.LocalDateTime, java.time.format.DateTimeFormatter.
The following external Kotlin packages are required and need to be added to the build.gradle file in the field called dependencies:
// stetho
implementation 'com.facebook.stetho:stetho:1.5.1'
implementation 'com.facebook.stetho:stetho-okhttp3:1.6.0'
// retrofit: library for api call
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
// http client
implementation "io.ktor:ktor-client-apache:2.1.3"
// GSON
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.google.code.gson:gson:2.8.6'
// coroutine
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4'
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4'
// read JSON file
implementation 'com.fasterxml.jackson.module:jackson-module-kotlin:2.13.2'
implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.1")
// KOTLIN DATAFRAME
implementation 'org.jetbrains.kotlinx:dataframe:0.8.1'
//DATE AND TIME
implementation("org.jetbrains.kotlinx:kotlinx-datetime:0.4.0")
This is a basic example on how to use the queryTimeSeries() function:
class Examples : AppCompatActivity(){
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
Stetho.initializeWithDefaults(this);
// create coroutine to use the functions: needed anywhere
// where you use the functions
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
lifecycleScope.launchWhenCreated {
val communityUsername = "kotlin-community"
val communityPassword = "s9qz-nJ7uEg+"
// /////////////////// EXAMPLE TIME SERIES /////////////////////////////////////////
// choose coordinates
val coordinates = listOf("51.5073219,-0.1276474", "35.3954127,-97.5959882")
// choose time interval: 3 hours
val timeInterval = "PT3H"
// choose parameters
val parameters = listOf("t_2m:C", "t_2m:K", "t_2m:F")
// choose model
val model = "mix"
// formatter for date and time
val formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss'.000Z'")
// choose start date
val now: LocalDateTime = LocalDateTime.now()
// choose end date
val tomorrow: LocalDateTime = now.plusDays(1)
// make a query to the API
val dfTimeseries1 = QueryTimeSeries()
.queryTimeSeries(coordinates, now.format(formatter), tomorrow.format(formatter),
timeInterval, parameters, communityUsername, communityPassword,
model = model, on_invalid = "fill_with_invalid")
println("first time series:")
println(dfTimeseries1)
val dfTimeseries2 = QueryTimeSeries()
.queryTimeSeries(
listOf("postal_CH9000", "postal_CH9050"),
now.format(formatter),
tomorrow.format(formatter),
"PT1H",
listOf("t_2m:C", "t_2m:K", "t_2m:F"), communityUsername, communityPassword,
on_invalid = "fill_with_invalid"
)
println("second time series:")
println(dfTimeseries2)
// select only one location
println("TS1: value at this lat and lon")
val smallerDF1 = dfTimeseries1.getTSatThisLatAndLon(51.507321,-0.127647)
println(smallerDF1)
println("TS2: value at this postcode")
val smallerDF2 = dfTimeseries2.getTSatThisPostCode("postal_CH9050")
println(smallerDF2)
}
}
}I/System.out: first time series:
I/System.out: lat lon validdate t_2m:C t_2m:K t_2m:F
I/System.out: 0 51.507322 -0.127647 2023-03-29T09:27:06 11.8 285.0 53.3
I/System.out: 1 51.507322 -0.127647 2023-03-29T12:27:06 13.8 286.9 56.8
I/System.out: 2 51.507322 -0.127647 2023-03-29T15:27:06 14.8 287.9 58.6
I/System.out: 3 51.507322 -0.127647 2023-03-29T18:27:06 13.0 286.1 55.3
I/System.out: 4 51.507322 -0.127647 2023-03-29T21:27:06 12.1 285.2 53.7
I/System.out: 5 51.507322 -0.127647 2023-03-30T00:27:06 11.7 284.8 53.0
I/System.out: 6 51.507322 -0.127647 2023-03-30T03:27:06 10.9 284.1 51.6
I/System.out: 7 51.507322 -0.127647 2023-03-30T06:27:06 10.9 284.1 51.7
I/System.out: 8 51.507322 -0.127647 2023-03-30T09:27:06 12.8 285.9 55.0
I/System.out: 9 35.395413 -97.595988 2023-03-29T09:27:06 2.1 275.3 35.9
I/System.out: 10 35.395413 -97.595988 2023-03-29T12:27:06 2.8 275.9 37.0
I/System.out: 11 35.395413 -97.595988 2023-03-29T15:27:06 10.7 283.8 51.2
I/System.out: 12 35.395413 -97.595988 2023-03-29T18:27:06 16.1 289.3 61.0
I/System.out: 13 35.395413 -97.595988 2023-03-29T21:27:06 17.9 291.0 64.2
I/System.out: 14 35.395413 -97.595988 2023-03-30T00:27:06 14.9 288.1 58.8
I/System.out: 15 35.395413 -97.595988 2023-03-30T03:27:06 11.4 284.6 52.6
I/System.out: 16 35.395413 -97.595988 2023-03-30T06:27:06 9.9 283.0 49.7
I/System.out: 17 35.395413 -97.595988 2023-03-30T09:27:06 9.6 282.7 49.2
I/System.out: second time series:
I/System.out: postal_code validdate t_2m:C t_2m:K t_2m:F
I/System.out: 0 postal_CH9000 2023-03-29T09:27:06 11.0 284.1 51.7
I/System.out: 1 postal_CH9000 2023-03-29T10:27:06 11.2 284.4 52.2
I/System.out: 2 postal_CH9000 2023-03-29T11:27:06 12.0 285.1 53.5
I/System.out: 3 postal_CH9000 2023-03-29T12:27:06 11.8 284.9 53.2
I/System.out: 4 postal_CH9000 2023-03-29T13:27:06 11.7 284.9 53.1
I/System.out: 5 postal_CH9000 2023-03-29T14:27:06 12.9 286.1 55.3
I/System.out: 6 postal_CH9000 2023-03-29T15:27:06 13.8 286.9 56.8
I/System.out: 7 postal_CH9000 2023-03-29T16:27:06 14.0 287.1 57.2
I/System.out: 8 postal_CH9000 2023-03-29T17:27:06 13.3 286.5 56.0
I/System.out: 9 postal_CH9000 2023-03-29T18:27:06 13.2 286.4 55.8
I/System.out: 10 postal_CH9000 2023-03-29T19:27:06 13.0 286.1 55.4
I/System.out: 11 postal_CH9000 2023-03-29T20:27:06 13.1 286.3 55.6
I/System.out: 12 postal_CH9000 2023-03-29T21:27:06 13.1 286.2 55.5
I/System.out: 13 postal_CH9000 2023-03-29T22:27:06 13.1 286.3 55.6
I/System.out: 14 postal_CH9000 2023-03-29T23:27:06 14.1 287.2 57.4
I/System.out: 15 postal_CH9000 2023-03-30T00:27:06 13.9 287.1 57.0
I/System.out: 16 postal_CH9000 2023-03-30T01:27:06 12.9 286.1 55.3
I/System.out: 17 postal_CH9000 2023-03-30T02:27:06 11.8 285.0 53.2
I/System.out: 18 postal_CH9000 2023-03-30T03:27:06 11.5 284.6 52.6
I/System.out: 19 postal_CH9000 2023-03-30T04:27:06 10.8 283.9 51.4
I/System.out: TS1: value at this lat and lon
I/System.out: lat lon validdate t_2m:C t_2m:K t_2m:F
I/System.out: 0 51.507322 -0.127647 2023-03-29T09:33:46 11.9 285.0 53.4
I/System.out: 1 51.507322 -0.127647 2023-03-29T12:33:46 14.0 287.2 57.2
I/System.out: 2 51.507322 -0.127647 2023-03-29T15:33:46 14.7 287.8 58.4
I/System.out: 3 51.507322 -0.127647 2023-03-29T18:33:46 12.9 286.1 55.3
I/System.out: TS2: value at this postcode
I/System.out: postal_code validdate t_2m:C t_2m:K t_2m:F
I/System.out: 0 postal_CH9050 2023-03-29T09:33:46 10.3 283.5 50.6
I/System.out: 1 postal_CH9050 2023-03-29T10:33:46 11.0 284.2 51.8
I/System.out: 2 postal_CH9050 2023-03-29T11:33:46 11.1 284.2 51.9
I/System.out: 3 postal_CH9050 2023-03-29T12:33:46 11.3 284.5 52.4
I/System.out: 4 postal_CH9050 2023-03-29T13:33:46 10.7 283.9 51.3
For a start, we recommend to read the Examples.kt file, where additional examples on how to use each function in the Kotlin connector are provided.