Skip To Content

Anomaly

Disponible con licencia de Image Analyst.

Resumen

Creates a raster object that contains the anomaly pixel values of the input multidimensional raster based on a time dimension interval and the anomaly calculation method.

Debate

Use the Anomaly function to calculate pixel value anomalies for temporal variables in a multidimensional raster object. For example, if you have daily precipitation data, you can find the pixels that are highly different from the monthly average precipitation values throughout your dataset. This function does not support calculating anomalies over a dimension other than time, such as height or depth.

The three mathematical methods for calculating anomaly values with this function are as follows:

  • Difference from mean = x - µ
    • x = pixel value in a slice
    • µ = mean of that pixel's values over a given time interval
  • Percent difference from mean = 100 × |x - µ| /[(x - µ)/2]
    • x = pixel value in a slice
    • µ = mean of that pixel's values over a given time interval
    • |x - µ| = absolute value of the difference between the value and the mean
  • Percent of average = x / µ
    • x = pixel value in a slice
    • µ = mean of that pixel's values over a given time interval

The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.

Sintaxis

Anomaly (in
_raster, {anomaly_type}, {temporal_interval})
ParámetroExplicaciónTipo de datos
in _raster

The input multidimensional raster.

Raster
anomaly_type

Specifies the method used to calculate the anomaly.

  • DIFFERENCE_FROM_MEANCalculates the difference between a pixel value and the mean of that pixel's values across slices defined by the interval. This is the default.
  • PERCENT_DIFFERENCE_FROM_MEANCalculates the percent difference between a pixel value and the mean of that pixel's values across slices defined by the interval.
  • PERCENT_OF_MEANCalculates the percent of the mean.

(El valor predeterminado es DIFFERENCE_FROM_MEAN)

String
temporal_interval

Specifies the temporal interval to use to calculate the average.

  • NONECalculates the average across all slices for each pixel. This is the default.
  • HOURLYCalculates the hourly average for each pixel.
  • DAILYCalculates the daily average for each pixel.
  • WEEKLYCalculates the weekly average for each pixel.
  • MONTHLYCalculates the monthly average for each pixel.
  • YEARLYCalculates the yearly average for each pixel.

(El valor predeterminado es ALL)

String
Valor de retorno
Tipo de datosExplicación
Raster

The output anomaly multidimensional raster.

Muestra de código

Anomaly example

Calculate precipitation anomalies across all slices and for monthly values.

Missing source code file

Temas relacionados