hydroGOF (version 0.2-2)

mae: Mean Absolute Error

Description

Mean absolute error between sim and obs, in the same units of them, with treatment of missing values.

Usage

mae(sim, obs, ...)
## S3 method for class 'default':
mae(sim, obs, na.rm=TRUE, ...)
## S3 method for class 'data.frame':
mae(sim, obs, na.rm=TRUE, ...)
## S3 method for class 'matrix':
mae(sim, obs, na.rm=TRUE, ...)

Arguments

sim

numeric, zoo, matrix or data.frame with simulated values

obs

numeric, zoo, matrix or data.frame with observed values

na.rm

a logical value indicating whether 'NA' should be stripped before the computation proceeds. When an 'NA' value is found at the i-th position in obs OR sim, the i-th value of obs AND sim ar

...

further arguments passed to or from other methods.

Value

• Mean absolute error between sim and obs. If sim and obs are matrixes, the returned value is a vector, with the mean absolute error between each column of sim and obs.

Details

$$mae = \frac{1}{N} \sum_{i=1}^N { \left|S_i - O_i) \right| }$$

References

http://en.wikipedia.org/wiki/Mean_absolute_error

See Also

me

Examples

obs <- 1:10
sim <- 1:10
mae(sim, obs)

obs <- 1:10
sim <- 2:11
mae(sim, obs)

##################
# Loading daily streamflows of the Ega River (Spain), from 1961 to 1970
require(zoo)
data(EgaEnEstellaQts)
obs <- EgaEnEstellaQts

# Generating a simulated daily time series, initially equal to the observed series
sim <- obs 

# Computing the mean absolute error for the "best" case
mae(sim=sim, obs=obs)

# Randomly changing the first 2000 elements of 'sim', by using a normal distribution 
# with mean 10 and standard deviation equal to 1 (default of 'rnorm').
sim[1:2000] <- obs[1:2000] + rnorm(2000, mean=10)

# Computing the new mean absolute error
mae(sim=sim, obs=obs)