VHSB_READHEADER - read a VH Lab Series Binary file header
H = vlt.file.custom_file_formats.vhsb_writeheader(FILE_OBJ_OR_FNAME, ...)
Reads the header portion of the vlt.file.fileobj or filename FILE_OBJ_OR_FNAME.
At the conclusion of reading, the FILEOBJ or file is closed.
This function returns a structure with the following fields (default in parentheses):
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version (1) | 32-bit integer describing version. Only 1 is allowed.
machine_format ('little-endian') | The machine format. The only value allowed is
| 'little_endian'.
X_data_size (64) | 32-bit integer describing the size (in bytes) of each
| data point in the X series.
X_data_type (4) | 8-bit unsigned integer describing whether X type is char (1), uint (2), int (3), or float (4)
Y_dim ([1 1]) | 64-bit unsigned integer describing the rows, columns, etc of each Y datum
Y_data_size (64) | 32-bit integer describing the size (in bytes) of each
| sample in the Y series.
Y_data_type (4) | 8-bit unsigned integer describing whether Y type is char (1), uint (2), int (3), or float (4)
X_stored (1) | Character 0 or 1 describing whether the X value of the series
| is stored in the file or just inferred from start and increment.
X_constantinterval (0) | Character 0 or 1 describing whether the X value of the series consists
| of a value that is incremented by a constant interval for each sample
X_start (0) | The value of the first X data sample (same size/type as X_data)
X_increment (0) | The value of the increment (same size/type as X_data)
|
X_units ('') | A 256 character string with the units of X (after any scaling)
Y_units ('') | A 256 character string with the units of Y (after any scaling)
X_usescale (0) | Character 0/1 should we scale what is read in X using parameters below?
Y_usescale (0) | Character 0/1 should we scale what is read in Y using parameters below?
X_scale (1) | 64-bit float scale factor
X_offset (0) | 64-bit float offset factor common to all X info
Y_scale (1) | 64-bit float scale factor
Y_offset (0) | 64-bit float offset factor common to all Y info
|
headersize (1836) | The full header size in bytes
num_samples (variable) | The calculated number of samples in the file.
X_skip_bytes (variable) | Number of bytes to skip over when reading X samples
Y_skip_bytes (variable) | Number of bytes to skip over when reading Y samples
sample_size (variable) | The size of each (x,y) pair of samples in bytes
filesize (variable) | The size of the file in bytes