tomopieces(1) General Commands Manual tomopieces(1) NAME tomopieces - compute pieces for combining tomograms SYNOPSIS tomopieces [options] filename DESCRIPTION Tomopieces figures out how to chop up a tomogram into pieces so that the Fourier transforms or other operations on each piece can be done in memory. It makes its decisions based on the maximum number of voxels that should be included in each piece. For typical processing, such as for taking an FFT, the memory consumed will be about four times the number of voxels, since data are typically stored in memory as real numbers. The program chooses a division of the volume that minimizes the total surface area of the extracted pieces, subject to specified constraints on the number of pieces in each dimension. Its one required input is the name of the tomogram file. Optional inputs specify the maximum number of voxels, the maximum number of pieces to extract in each dimension, the border sizes for padding (and tapering) the extracted pieces, the amount of overlap to generate between the extracted pieces, and whether output is to be written directly to a chunked HDF file. Its first line of output is the number of pieces in X, Y, and Z. For a normal output file, this is followed by the starting and ending index coordinates in X, Y, and Z required for extracting each piece with Tap- eroutvol, then three lines with the index coordinates required for putting the pieces back together with Assemblevol (first the X coordi- nates for each position in X, then the Y coordinates for each position in Y, then the Z coordinates for each position in Z). For a chunked HDF file, there are two output line for each piece: one with X, Y, and Z coordinates to extract, then one with the starting and ending X, Y, and Z indexes in the padded chunk of data to write out, and the X, Y, and Z coordinates at which to write the chunk in the output file. OPTIONS Tomopieces uses the PIP package for input (see the manual page for pip). The following options can be specified either as command line arguments (with the -) or one per line in a command file or parameter file (without the -). Options can be abbreviated to unique letters; the currently valid abbreviations for short names are shown in paren- theses. -tomogram (-t) OR -TomogramOrSizeXYZ File name Input file to be cut up, or the dimensions in X, Y and Z -megavox (-me) OR -MegaVoxels Floating point Maximum number of megavoxels to allow in each piece (default 80) -xpad (-xp) OR -XPadding Integer Number of pixels to pad on each side in X (default 8) -ypad (-yp) OR -YPadding Integer Number of pixels to pad on each side in Y (default 4) -zpad (-zp) OR -ZPadding Integer Number of pixels to pad on each side in Z (default 8) -xmaxpiece (-xm) OR -XMaximumPieces Integer Maximum number of pieces in X. Enter -1 for essentially no con- straints (a maximum of X image size divided by 2). The default is 0 for X and Y, which will make the total number of pieces in X and Y be no more than 100. If the maximum for Y is set to 1, a value of 0 for X will make the number of pieces in X be no more than 100. These constraints will allow Assemblevol to keep all files in one layer in Z open at once. -ymaxpiece (-ym) OR -YMaximumPieces Integer Maximum number of pieces in Y. Enter -1 for essentially no con- straints (a maximum of Y image size divided by 2). The default is 0; see entry for XMaximumPieces. If the maximum for X is set to 1, a value of 0 for Y will make the number of pieces in Y be no more than 100. -zmaxpiece (-zm) OR -ZMaximumPieces Integer Maximum number of pieces in Z. The default is -1 for essen- tially no constraints (a maximum of Z image size divided by 2). -minoverlap (-mi) OR -MinimumOverlap Integer Minimum number of pixels to overlap between pieces (default 4) -hdf (-hd) OR -ChunksForHDF Set up for direct output to a chunked HDF file. The program will generate equally spaced chunks on each axis with a size that minimizes the wasted space in the last chunk. -nofft (-n) OR -NoFFTSizes Do not adjust the padding to give sizes suitable for an FFT. If this option is entered, be sure that it is also sent to Taper- outvol(1). -param (-p) OR -ParameterFile Parameter file Read parameter entries as keyword-value pairs from a parameter file. -help (-he) OR -usage Print help output -StandardInput Read parameter entries from standard input. HISTORY Written by David Mastronarde; revised for pieces in X 3/1/01 Converted to PIP input and generalized to 3 dimensions, 6/14/04 BUGS Email bug reports to mast at colorado dot edu. IMOD 5.0.2 tomopieces(1)