Interpolate a smooth function stored on a grid onto a grid with a smaller grid spacing.
This action takes a function evaluated on a grid as input and can be used to interpolate the values of that function on to a finer grained grid. The interpolation within this algorithm is done using splines.
The input below can be used to post process a trajectory. It calculates a HISTOGRAM as a function the distance between atoms 1 and 2 using kernel density estimation. During the calculation the values of the kernels are evaluated at 100 points on a uniform grid between 0.0 and 3.0. Prior to outputting this function at the end of the simulation this function is interpolated onto a finer grid of 200 points between 0.0 and 3.0.
x: DISTANCEATOMS=1,2 hA1: HISTOGRAMthe pair of atom that we are calculating the distance between.ARG=xthe input for this action is the scalar output from one or more other actions.GRID_MIN=0.0compulsory keyword the lower bounds for the gridGRID_MAX=3.0compulsory keyword the upper bounds for the gridGRID_BIN=100the number of bins for the gridBANDWIDTH=0.1 ii: INTERPOLATE_GRIDcompulsory keyword the bandwidths for kernel density estimationGRID=hA1compulsory keyword the action that creates the input grid you would like to useGRID_BIN=200 DUMPGRIDthe number of bins for the gridGRID=iicompulsory keyword the action that creates the grid you would like to outputFILE=histo.datcompulsory keyword ( default=density ) the file on which to write the grid.
STRIDE | ( default=1 ) the frequency with which the data should be collected and added to the quantity being averaged |
CLEAR | ( default=0 ) the frequency with which to clear all the accumulated data. The default value of 0 implies that all the data will be used and that the grid will never be cleared |
NORMALIZATION | ( default=true ) This controls how the data is normalized it can be set equal to true, false or ndata. The differences between these options are explained in the manual page for HISTOGRAM |
GRID | the action that creates the input grid you would like to use |
SERIAL | ( default=off ) do the calculation in serial. Do not use MPI |
LOWMEM | ( default=off ) lower the memory requirements |
TIMINGS | ( default=off ) output information on the timings of the various parts of the calculation |
LOGWEIGHTS | list of actions that calculates log weights that should be used to weight configurations when calculating averages |
CONCENTRATION | the concentration parameter for Von Mises-Fisher distributions |
COMPONENT | if your input is a vector field use this to specify the component of the input vector field for which you wish to use |
GRID_BIN | the number of bins for the grid |
GRID_SPACING | the approximate grid spacing (to be used as an alternative or together with GRID_BIN) |