volroc - Volume rate of change

Syntax

vroc = volroc(tvolume nTimes)
vrocts = volroc(tsobj, nTimes)
vrocts = volroc(tsobj, nTimes, ParameterName, ParameterValue)

Arguments

`tvolume`	Volume traded.
`nTimes`	(Optional) Time difference. Default = 12.
`tsobj`	Financial time series object.

Description

vroc = volroc(tvolume nTimes) calculates the volume rate of change, vroc, from the volume traded data tvolume. If nTimes is specified, the volume rate of change is calculated between the current volume and the volume nTimes ago.

vrocts = volroc(tsobj, nTimes) calculates the volume rate of change, vrocts, from the financial time series object tsobj. The vrocts output is a financial time series object with similar dates as tsobj and a data series named VolumeROC. If nTimes is specified, the volume rate of change is calculated between the current volume and the volume nTimes ago.

vrocts = volroc(tsobj, nTimes, ParameterName, ParameterValue) specifies the name for the required data series when it is different from the default name. The valid parameter name is

VolumeName: volume traded series name

The parameter value is a string that represents the valid parameter name.

Note, to compute a quantity over n periods, you must specify n+1 for nTimes. If you specify nTimes = 0, the function returns your original time series.

Examples

Compute the volume rate of change for Disney stock and plot the results:

load disney.mat
dis_VolRoc = volroc(dis)
plot(dis_VolRoc)
title('Volume Rate of Change for Disney')

References

Achelis, Steven B., Technical Analysis from A to Z, Second printing, McGraw-Hill, 1995, pp. 310 - 311.