tween_states
(Package: tweenr) :
Tween a list of data.frames representing states
This function is intended to create smooth transitions between states of data. States are defined as full data.frames or data.frames containing only the columns with change. Each state can have a defined period of pause, the transition length between each states can be defined as well as the easing function.
tweenr is a small collection of functions to help you in creating intermediary representations of your data, i.e. interpolating states of data. As such it's a great match for packages such as animate and gganimate, since it can work directly with data.frames of data, but it also provide fast and efficient interpolaters for numeric, date, datetime and colour that are vectorized and thus more efficient to use than the build in interpolation functions (mainly approx and colorRamp).
This set of functions can be used to interpolate between single data types, i.e. data not part of data.frames but stored in vectors. All functions come in two flavours: the standard and a *_t version. The standard reads the data as a list of states, each tween matched element-wise from state to state. The *_t version uses the transposed representation where each element is a vector of states. The standard approach can be used when each tween has the same number of states and you want to control the number of point in each state transition. The latter is useful when each tween consists of different numbers of states and/or you want to specify the total number of points for each tween.
This function is intended for use when you have a data.frame of events at different time points. This could be the appearance of an observation for example. This function replicates your data nframes times and calculates the duration of each frame. At each frame each row is assigned an age based on the progression of frames and the entry point of in time for that row. A negative age means that the row has not appeared yet.
tween_elements
(Package: tweenr) :
Create frames based on individual element states
This function creates tweens for each observation individually, in cases where the data doesn't pass through collective states but consists of fully independent transitions. Each observation is identified by an id and each state must have a time associated with it.
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