alterheader(1) General Commands Manual alterheader(1) NAME alterheader - to alter header information in an MRC file SYNOPSIS alterheader [filename] DESCRIPTION Alterheader allows one to alter header information in an MRC file with- out rewriting the file. The program can be run interactively or with command-line arguments. When run interactively, for each standard header entry selected by the user, the program prints the current val- ues and asks for new values, checking for legality in some cases. Other operations can be performed as described below. Multiple changes can be made. When run interactively, the header is not written to the file until you enter DONE to exit the program, so you can interrupt with Ctrl-C to discard changes. The interactive mode is thus much safer to use, although inconvenient from scripts. The interactive entries for the different options are not case sensitive but are shown below in their upper-case form. Even when running interactively, the file name can be entered on the command line; if not, the program will ask for it. However, the addi- tion of any option argument on the command line makes the program require a filename as well and run without any interaction. The MRC header stores three pieces of information about size: the num- ber of pixels in X, Y, and Z, which is output as "columns, rows, sec- tions", the sample grid size, output as "grid x,y,z", and the cell size, which is not directly output in the standard printing of the header. The pixel spacing in Angstroms is defined to be the ratio of the cell size to the sample size in each dimension. Programs in IMOD generally try to keep the sample size the same as the image size, and to set the cell size to achieve an appropriate pixel spacing. OPTIONS When run with command-line arguments, Alterheader uses the PIP package for input (see the manual page for pip). The order in which options are entered is not preserved with PIP input. Options are processed in the same order as they are listed in the brief summary of options when running interactively, namely: -org, -cel, -dat, -del, -map, -sam, -tlt, -firsttlt, -rottlt, -mmm, -rms, -fixpixel, -feipixel, -extrafix, -modefix, -invertorg, -setmmm, -real, -fft, -ispg, -4bit, -toggleorg, -gridfix, -title. The following options can be specified either as command line arguments (with the -) or one per line in a command file or parameter file (with- out the -). Options can be abbreviated to unique letters; the cur- rently valid abbreviations for short names are shown in parentheses. -org (-o) OR -Origin Three floats (Interactive ORG) Change the origin in X, Y, Z. In IMOD, the origin is defined as the coordinates of the origin relative to the lower-left corner of the first section in the file, in units scaled by the pixel size. The origin is defined in the opposite way in UCSF Chimera; use INVERTORG/-invertorg to switch the sign of the origin values. -cel (-c) OR -CellSize Three floats (Interactive CEL) Change the cell size in X, Y, Z. This will show up as a change in pixel spacing, as described above. -del (-d) OR -PixelSize Three floats (Interactive DEL) Change the pixel size in X, Y, Z to given values. The program will change the cell size so that the ratio of cell to sample size will give the entered pixel size. -map (-ma) OR -MapIndexes Three integers (Interactive MAP) Set mapping from X, Y, Z to rows, columns, sections. The only effect of this in IMOD is to reorder the sample grid and pixel spacing values by the given mapping. Do not use it. -sam (-sa) OR -SampleSize Three integers (Interactive SAM) Set sampling in X, Y, Z. See note above on IMOD conventions. -tlt (-tl) OR -TiltCurrent Three floats (Interactive TLT) Change current tilt angles to given alpha, beta, gamma. These values will be used to apply a rotation to a model loaded into 3dmod along with the image. -firsttlt (-fir) OR -TiltOriginal Three floats (Interactive TLT_ORIG) Change original tilt angles. These angles have no effect in IMOD. -rottlt (-ro) OR -RotateTilt Three floats (Interactive TLT_ROT) Rotate current tilt angles by the given alpha, beta, and gamma values, where the rotations are applied the order gamma (around Z), beta (around Y), alpha (around X). -mmm (-mm) OR -MinMaxMean (Interactive MMM) Read the file to recompute the minimum, maxi- mum, and mean densities and the RMS density. -rms (-rm) OR -RootMeanSquare (Interactive RMS) Print the current RMS value (root-mean-square deviation from the mean density) then do the same operation as MMM/-mmm. -fixpixel (-fix) OR -FixPixel (Interactive FIXPIXEL) Set the cell and sample sizes the same as the image size, resulting in a pixel spacing of 1, 1, 1. -gridfix (-g) OR -FixGrid (Interactive FIXGRID) Set the sample size the same as the image size and modify the cell size so as to preserve the pixel size. -feipixel (-fe) OR -FeiPixel Integer (Interactive FEIPIXEL) Set the pixel spacing in X, Y, Z from the value for the pixel size of the first section in an Agard/FEI-style extended header. If the existing pixel spacing is not 1 but is equal to 2, 3, or 4, this will be assumed to represent a binning of the data, and the pixel size will be mul- tiplied by this value. However, if the pixel size has already been transferred or the pixel spacing does not correspond to a small integer, the program will transfer the pixel size only if a positive number is entered for this option. It will exit if 0 or a negative nunber is entered for this option when running with command-line arguments, or if -1 is entered when running interactively. -extrafix (-e) OR -FixExtra (Interactive FIXEXTRA) Change the flags in the header so that 3dmod no longer interprets the extended header as having piece coordinates for a montage. -modefix (-mo) OR -FixMode (Interactive FIXMODE) Change mode from 1 (signed 16-bit inte- ger) to 6 (unsigned) or from 6 to 1. The program will warn if the current minimum and maximum densities indicate that there are values that will not be interpreted correctly after the change. -invertorg (-in) OR -InvertOrigin (Interactive INVERTORG) Invert the signs of the X, Y, and Z origin values to switch the header between different definitions of the origin. This operation will not change the flag about the origin inversion and will invert the origin values seen inside IMOD programs as well as those stored in the header. -toggleorg (-to) OR -ToggleOrigin (Interactive INVERTORG) Invert the signs of the X, Y, and Z origin values stored in the file header without changing the values seen inside IMOD programs. This will be done by setting the flag that determines whether values are inverted on output to the file or not. -setmmm (-se) OR -SetMinMaxMean Three floats (Interactive SETMMM) Set the minimum, maximum, and mean densi- ties directly with the given values. -real (-rea) OR -RealMode (Interactive REAL) Change a mode 4 FFT file to mode 2 and dou- ble the X size. -fft (-ff) OR -ComplexMode (Interactive FFT) Change a mode 2 file to mode 4 and divide the X size by 2; this can be done only if the X size is two times an odd number. -4bit (-4) OR -Change4BitMode Integer (Interactive 4BIT) For a positive entry, change a mode 0 file to the 4-bit mode 101 and double the size in X that is stored in the header. The header listing will look the same if the file was already recognized as containing 4-bit data packed into bytes. For a negative entry, change a mode 101 file back to mode 0 and divide the X size by 2 (X size must be even). -ispg (-is) OR -SpaceGroup Integer (Interactive ISPG) Change the space group entry, which should be 0 for an image stack, 1 for an image volume, and 401 for a stack with multiple volumes. -title (-ti) OR -TitleToAdd Text string Add the given string as a new label (title) after all other labels in the file, unless the -position option is entered with a specific position. This option is not equivalent to the interactive LAB option. If there are already 10 labels, the last one will be replaced. Be sure to quote the whole string when running from the command line. -position (-p) OR -PositionForTitle Integer Position that new title should be placed in, numbered from 1. Note that a positive number is entered here, unlike the 0 or negative number entered with the interactive LAB option. -remove (-rem) OR -RemoveTitles List of integer ranges List of existing titles to remove, numbered from 1; comma-sepa- rate ranges may be entered. This option can be used together with -title and -position titles will be removed before one is added with -title. -help (-h) OR -usage Print help output -StandardInput Read parameter entries from standard input. ADDITIONAL INTERACTIVE OPTIONS LAB - Delete a list of labels, or add a label. You will see a numbered list of existing labels. To delete some labels, enter a range (comma- separated list) of the numbers to delete. To add a label, enter the negative of the label number after which you want the new label to appear. Enter 0 to have the new label become the first one, or -9 to have it added after the last one. Then enter the complete label (the date/time stamp will not be added). If you need to program this opera- tion in a script, first delete the tenth label, if any, with entries "lab - 10 - 1 - lab -9 your_new_label". DAT - Change data type, which is defined as 0 for normal data, 1 for tilt series, 2 for stereo pairs, 3 for averaged data, 4 for averaged stereo pairs. The only non-zero value that could be useful in IMOD is 1; with this value you can set a starting angle and increment that will be accepted by the Tilt program instead of entering angles from a file. HELP - print a summary of these options. DONE - Write the modified header to the file and exit. HISTORY Written by David Mastronarde 10/24/88; ported to SGI 12/7/94. Converted to PIP input, 10/15/14. BUGS Email bug reports to mast at colorado dot edu. IMOD 4.11.0 alterheader(1)