Deflate TOKI compression

Data compressed by TOKI method can be read.

TOKI compression

In some simulation data, a handful of particles interact rapidly, while other particles just move near linearly. In such case, saving all simulation data in short time step (required by interacting particles) is very inefficient.
In TOKI compression, only data of a part of particles is saved every step, while other particles are saved with longer time step.

Note that TOKI deflation works only with HDF5 file.
sequentialfile00.h5
snap00All particle data: position, velocity, acceleration, jerk, and so on.
snap01Partial data for particles that need updating.
snap02Partial data for particles that need updating.
........
sequentialfile01.h5
snap00All particle data: position, velocity, acceleration, jerk, and so on.
snap01Partial data for particles that need updating.
snap02Partial data for particles that need updating.
........

In first frame (first group), data of all particles is required. In other frames (groups), set only partial data that require updating. Using index data set to identify updated particles. See description in Loading HDF5, In normal (Not TOKI) mode, Zindaiji 3 calculate acceleration and jerk from position and velocity of 2 frames. Then, interpolate particles using the equation position(dt) = position at 0 + velocity x dt + (1/2) acceleration x dt x dt + (1/6) jerk x dt x dt x dt.
In this case, continuity of particle in two steps is guaranteed.

In TOKI mode, Zindaiji3 assume that continuous data is given, and not calculate parameters such as acceleration and jerks.
Thus, continuity is not guaranteed.
(If particles move discontinuosly, compressed data has some error...) In the case that a particle vanishes in some time step in a file, you must set set parameter of non-existing particle to be invisible one. (For example set their positions beyond the cutting distance, or set radius to be 0). This is because there is no distinguish between vanished particles and particles that is not needed to be updated. When the scene comes to a next file, particles without data actually vanishes.

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inserted by FC2 system