Accuracy indices

{lvmisc} contains a group of useful functions to compute basic indices of accuracy. These functions can be divided in those which compute element-wise values and those which compute average values:

You may notice that the majority of these functions have common prefixes (error_ and mean_error_), intended to facilitate the use, as most text editors have an auto-complete feature. Also all of the accuracy indices functions take actual and predicted as arguments, and the functions that return average values have na.rm = TRUE in addition.

Element-wise

Error: `error()`

It simply subtracts the predicted from the actual values.

Formula: $a_i - p_i$

Absolute error: `error_abs()`

It returns the absolute values of the error() function.

Formula: $|a_i - p_i|$

Percent error: `error_pct()`

Divides the error by the actual values.

Formula: $\frac{a_i - p_i}{a_i}\cdot100$

Absolute percent error: `error_abs_pct()`

Returns the absolute values of the error_pct() function.

Formula: $\frac{|a_i - p_i|}{|a_i|}\cdot100$

Squared error: `error_sqr()`

It squares the values of the error() function.

Formula: $(a_i - p_i)^2$

Average

Mean error: `mean_error()`

It is the average of the error.

Formula: $\frac{1}{N}\sum_{i = 1}^{N}(a_i - p_i)$

Mean absolute error: `mean_error_abs()`

Computes the average of the absolute error.

Formula: $\frac{1}{N}\sum_{i = 1}^{N}|a_i - p_i|$

Mean percent error: `mean_error_pct()`

The average of the percent error.

Formula: $\frac{1}{N}\sum_{i = 1}^{N}\frac{a_i - p_i}{a_i}\cdot100$

Mean absolute percent error: `mean_error_abs_pct()`

It is the average of the absolute percent error.

Formula: $\frac{1}{N}\sum_{i = 1}^{N}\frac{|a_i - p_i|}{|a_i|}\cdot100$

Mean squared error: `mean_error_sqr()`

Averages the mean squared error.

Formula: $\frac{1}{N}\sum_{i = 1}^{N}(a_i - p_i)^2$

Root mean squared error: `mean_error_sqr_root()`

It takes the square root of the mean squared error.

Formula: $\sqrt{\frac{1}{N}\sum_{i = 1}^{N}(a_i - p_i)^2}$

Bias: `bias()`

Alias to mean_error().

Limits of agreement: `loa()`

Formula: $bias \pm 1.96\sigma$

Where $\sigma$ is the standard deviation.

Accuracy indices

Element-wise

Error: error()

Absolute error: error_abs()

Percent error: error_pct()

Absolute percent error: error_abs_pct()

Squared error: error_sqr()

Average

Mean error: mean_error()

Mean absolute error: mean_error_abs()

Mean percent error: mean_error_pct()

Mean absolute percent error: mean_error_abs_pct()

Mean squared error: mean_error_sqr()

Root mean squared error: mean_error_sqr_root()

Bias: bias()

Limits of agreement: loa()