aRTquerier {aRT} | R Documentation

## Class aRTquerier

### Description

Class that manipulates the result of a query in a database. It returns the objects one by one, and can slide a temporal aRTtheme. This class is different from the others because it does not store anything in the database.

### Objects from the Class

`obj = new("aRTquerier", parent,... )` Objects can be created by calls of the form `openQuerier(parent, loadgeom=T, loadatt=T)`, or `openQuerier(theme, chronon="hourofday")`.

### Arguments

parent:
  Object of class {`aRTlayer`,`aRTtheme`}
loadgeom:
  Will geometry be retrieved?
loadatt:
  Will attributes be retrieved?
chronon:
  A temporal slicing.
table:
  (not implemented)
att:
  (not implemented)
stat:
  (not implemented)

### Chronon

- nochronon
- second
- minute
- hour
- day
- month
- year
- dayofweek
- dayofmonth
- dayofyear
- monthofyear
- season
- weekofyear
- hourofday
- minuteofhour
- secondofminute

### Stat

- nostat
- sum
- max
- min
- count
- validcount
- stddev
- kernek
- mean
- variance
- skewness
- kurtosis
- median
- varcoeff
- mode

### Extends

Class `aRTcomponent`, directly.

### Methods

getData:
  Returns the next element of the query result in the actual slide.
nextSlide:
  Loads the next slide, if there is a temporal sliding. A temporal query needs to load one slide before using `getData` for getting its elements. Non-temporal queries can't use this function. Note that you can do a non-temporal query in a temporal layer.

### Author(s)

Pedro Ribeiro de Andrade Neto

[Package aRT version 0.4-0 Index]