# Incremental Statistics > Standard library functions for computing statistics incrementally.
## Usage ```javascript var ns = require( '@stdlib/stats/incr' ); ``` #### ns Standard library functions for computing statistics incrementally. ```javascript var incr = ns; // returns {...} ```
- [`incrapcorr( [mx, my] )`][@stdlib/stats/incr/apcorr]: compute a sample absolute Pearson product-moment correlation coefficient incrementally. - [`incrcount()`][@stdlib/stats/incr/count]: compute a count incrementally. - [`incrcovariance( [mx, my] )`][@stdlib/stats/incr/covariance]: compute an unbiased sample covariance incrementally. - [`incrcovmat( out[, means] )`][@stdlib/stats/incr/covmat]: compute an unbiased sample covariance matrix incrementally. - [`incrcv( [mean] )`][@stdlib/stats/incr/cv]: compute the coefficient of variation (CV) incrementally. - [`increwmean( alpha )`][@stdlib/stats/incr/ewmean]: compute an exponentially weighted mean incrementally. - [`increwstdev( alpha )`][@stdlib/stats/incr/ewstdev]: compute an exponentially weighted standard deviation incrementally. - [`increwvariance( alpha )`][@stdlib/stats/incr/ewvariance]: compute an exponentially weighted variance incrementally. - [`incrgmean()`][@stdlib/stats/incr/gmean]: compute a geometric mean incrementally. - [`incrgrubbs( [options] )`][@stdlib/stats/incr/grubbs]: grubbs' test for outliers. - [`incrhmean()`][@stdlib/stats/incr/hmean]: compute a harmonic mean incrementally. - [`incrkurtosis()`][@stdlib/stats/incr/kurtosis]: compute a corrected sample excess kurtosis incrementally. - [`incrmaape()`][@stdlib/stats/incr/maape]: compute the mean arctangent absolute percentage error (MAAPE) incrementally. - [`incrmae()`][@stdlib/stats/incr/mae]: compute the mean absolute error (MAE) incrementally. - [`incrmapcorr( window[, mx, my] )`][@stdlib/stats/incr/mapcorr]: compute a moving sample absolute Pearson product-moment correlation coefficient incrementally. - [`incrmape()`][@stdlib/stats/incr/mape]: compute the mean absolute percentage error (MAPE) incrementally. - [`incrmax()`][@stdlib/stats/incr/max]: compute a maximum value incrementally. - [`incrmaxabs()`][@stdlib/stats/incr/maxabs]: compute a maximum absolute value incrementally. - [`incrmcovariance( window[, mx, my] )`][@stdlib/stats/incr/mcovariance]: compute a moving unbiased sample covariance incrementally. - [`incrmcv( window[, mean] )`][@stdlib/stats/incr/mcv]: compute a moving coefficient of variation (CV) incrementally. - [`incrmda()`][@stdlib/stats/incr/mda]: compute the mean directional accuracy (MDA) incrementally. - [`incrme()`][@stdlib/stats/incr/me]: compute the mean error (ME) incrementally. - [`incrmean()`][@stdlib/stats/incr/mean]: compute an arithmetic mean incrementally. - [`incrmeanabs()`][@stdlib/stats/incr/meanabs]: compute an arithmetic mean of absolute values incrementally. - [`incrmeanabs2()`][@stdlib/stats/incr/meanabs2]: compute an arithmetic mean of squared absolute values incrementally. - [`incrmeanstdev( [out] )`][@stdlib/stats/incr/meanstdev]: compute an arithmetic mean and a corrected sample standard deviation incrementally. - [`incrmeanvar( [out] )`][@stdlib/stats/incr/meanvar]: compute an arithmetic mean and an unbiased sample variance incrementally. - [`incrmgmean( window )`][@stdlib/stats/incr/mgmean]: compute a moving geometric mean incrementally. - [`incrmgrubbs( window[, options] )`][@stdlib/stats/incr/mgrubbs]: moving Grubbs' test for outliers. - [`incrmhmean( window )`][@stdlib/stats/incr/mhmean]: compute a moving harmonic mean incrementally. - [`incrmidrange()`][@stdlib/stats/incr/midrange]: compute a mid-range incrementally. - [`incrmin()`][@stdlib/stats/incr/min]: compute a minimum value incrementally. - [`incrminabs()`][@stdlib/stats/incr/minabs]: compute a minimum absolute value incrementally. - [`incrminmax( [out] )`][@stdlib/stats/incr/minmax]: compute a minimum and maximum incrementally. - [`incrminmaxabs( [out] )`][@stdlib/stats/incr/minmaxabs]: compute minimum and maximum absolute values incrementally. - [`incrmmaape( window )`][@stdlib/stats/incr/mmaape]: compute a moving mean arctangent absolute percentage error (MAAPE) incrementally. - [`incrmmae( window )`][@stdlib/stats/incr/mmae]: compute a moving mean absolute error (MAE) incrementally. - [`incrmmape( window )`][@stdlib/stats/incr/mmape]: compute a moving mean absolute percentage error incrementally. - [`incrmmax( window )`][@stdlib/stats/incr/mmax]: compute a moving maximum value incrementally. - [`incrmmaxabs( window )`][@stdlib/stats/incr/mmaxabs]: compute a moving maximum absolute value incrementally. - [`incrmmda( window )`][@stdlib/stats/incr/mmda]: compute a moving mean directional accuracy (MDA) incrementally. - [`incrmme( window )`][@stdlib/stats/incr/mme]: compute a moving mean error (ME) incrementally. - [`incrmmean( window )`][@stdlib/stats/incr/mmean]: compute a moving arithmetic mean incrementally. - [`incrmmeanabs( window )`][@stdlib/stats/incr/mmeanabs]: compute a moving arithmetic mean of absolute values incrementally. - [`incrmmeanabs2( window )`][@stdlib/stats/incr/mmeanabs2]: compute a moving arithmetic mean of squared absolute values incrementally. - [`incrmmeanstdev( [out,] window )`][@stdlib/stats/incr/mmeanstdev]: compute a moving arithmetic mean and corrected sample standard deviation incrementally. - [`incrmmeanvar( [out,] window )`][@stdlib/stats/incr/mmeanvar]: compute a moving arithmetic mean and unbiased sample variance incrementally. - [`incrmmidrange( window )`][@stdlib/stats/incr/mmidrange]: compute a moving mid-range incrementally. - [`incrmmin( window )`][@stdlib/stats/incr/mmin]: compute a moving minimum value incrementally. - [`incrmminabs( window )`][@stdlib/stats/incr/mminabs]: compute a moving minimum absolute value incrementally. - [`incrmminmax( [out,] window )`][@stdlib/stats/incr/mminmax]: compute a moving minimum and maximum incrementally. - [`incrmminmaxabs( [out,] window )`][@stdlib/stats/incr/mminmaxabs]: compute moving minimum and maximum absolute values incrementally. - [`incrmmpe( window )`][@stdlib/stats/incr/mmpe]: compute a moving mean percentage error (MPE) incrementally. - [`incrmmse( window )`][@stdlib/stats/incr/mmse]: compute a moving mean squared error (MSE) incrementally. - [`incrmpcorr( window[, mx, my] )`][@stdlib/stats/incr/mpcorr]: compute a moving sample Pearson product-moment correlation coefficient incrementally. - [`incrmpcorr2( window[, mx, my] )`][@stdlib/stats/incr/mpcorr2]: compute a moving squared sample Pearson product-moment correlation coefficient incrementally. - [`incrmpcorrdist( window[, mx, my] )`][@stdlib/stats/incr/mpcorrdist]: compute a moving sample Pearson product-moment correlation distance incrementally. - [`incrmpe()`][@stdlib/stats/incr/mpe]: compute the mean percentage error (MPE) incrementally. - [`incrmprod( window )`][@stdlib/stats/incr/mprod]: compute a moving product incrementally. - [`incrmrange( window )`][@stdlib/stats/incr/mrange]: compute a moving range incrementally. - [`incrmrmse( window )`][@stdlib/stats/incr/mrmse]: compute a moving root mean squared error (RMSE) incrementally. - [`incrmrss( window )`][@stdlib/stats/incr/mrss]: compute a moving residual sum of squares (RSS) incrementally. - [`incrmse()`][@stdlib/stats/incr/mse]: compute the mean squared error (MSE) incrementally. - [`incrmstdev( window[, mean] )`][@stdlib/stats/incr/mstdev]: compute a moving corrected sample standard deviation incrementally. - [`incrmsum( window )`][@stdlib/stats/incr/msum]: compute a moving sum incrementally. - [`incrmsumabs( window )`][@stdlib/stats/incr/msumabs]: compute a moving sum of absolute values incrementally. - [`incrmsumabs2( window )`][@stdlib/stats/incr/msumabs2]: compute a moving sum of squared absolute values incrementally. - [`incrmsummary( window )`][@stdlib/stats/incr/msummary]: compute a moving statistical summary incrementally. - [`incrmsumprod( window )`][@stdlib/stats/incr/msumprod]: compute a moving sum of products incrementally. - [`incrmvariance( window[, mean] )`][@stdlib/stats/incr/mvariance]: compute a moving unbiased sample variance incrementally. - [`incrmvmr( window[, mean] )`][@stdlib/stats/incr/mvmr]: compute a moving variance-to-mean ratio (VMR) incrementally. - [`incrnancount()`][@stdlib/stats/incr/nancount]: compute a count incrementally, ignoring `NaN` values. - [`incrnansum()`][@stdlib/stats/incr/nansum]: compute a sum incrementally, ignoring `NaN` values. - [`incrnansumabs()`][@stdlib/stats/incr/nansumabs]: compute a sum of absolute values incrementally, ignoring `NaN` values. - [`incrnansumabs2()`][@stdlib/stats/incr/nansumabs2]: compute a sum of squared absolute values incrementally, ignoring `NaN` values. - [`incrpcorr( [mx, my] )`][@stdlib/stats/incr/pcorr]: compute a sample Pearson product-moment correlation coefficient incrementally. - [`incrpcorr2( [mx, my] )`][@stdlib/stats/incr/pcorr2]: compute a squared sample Pearson product-moment correlation coefficient incrementally. - [`incrpcorrdist( [mx, my] )`][@stdlib/stats/incr/pcorrdist]: compute a sample Pearson product-moment correlation distance incrementally. - [`incrpcorrdistmat( out[, means] )`][@stdlib/stats/incr/pcorrdistmat]: compute a sample Pearson product-moment correlation distance matrix incrementally. - [`incrpcorrmat( out[, means] )`][@stdlib/stats/incr/pcorrmat]: compute a sample Pearson product-moment correlation matrix incrementally. - [`incrprod()`][@stdlib/stats/incr/prod]: compute a product incrementally. - [`incrrange()`][@stdlib/stats/incr/range]: compute a range incrementally. - [`incrrmse()`][@stdlib/stats/incr/rmse]: compute the root mean squared error (RMSE) incrementally. - [`incrrss()`][@stdlib/stats/incr/rss]: compute the residual sum of squares (RSS) incrementally. - [`incrskewness()`][@stdlib/stats/incr/skewness]: compute a corrected sample skewness incrementally. - [`incrstdev( [mean] )`][@stdlib/stats/incr/stdev]: compute a corrected sample standard deviation incrementally. - [`incrsum()`][@stdlib/stats/incr/sum]: compute a sum incrementally. - [`incrsumabs()`][@stdlib/stats/incr/sumabs]: compute a sum of absolute values incrementally. - [`incrsumabs2()`][@stdlib/stats/incr/sumabs2]: compute a sum of squared absolute values incrementally. - [`incrsummary()`][@stdlib/stats/incr/summary]: compute a statistical summary incrementally. - [`incrsumprod()`][@stdlib/stats/incr/sumprod]: compute a sum of products incrementally. - [`incrvariance( [mean] )`][@stdlib/stats/incr/variance]: compute an unbiased sample variance incrementally. - [`incrvmr( [mean] )`][@stdlib/stats/incr/vmr]: compute a variance-to-mean ratio (VMR) incrementally. - [`incrwmean()`][@stdlib/stats/incr/wmean]: compute a weighted arithmetic mean incrementally.
## Examples ```javascript var getKeys = require( '@stdlib/utils/keys' ); var ns = require( '@stdlib/stats/incr' ); console.log( getKeys( ns ) ); ```