drms_segment.h

drms_create_segment_prototypes drms_segment_autoscale drms_segment_createinfocon drms_segment_destroyinfocon drms_segment_fclose drms_segment_filename drms_segment_fopen drms_segment_fprint drms_segment_getblocksize drms_segment_getdims drms_segment_lookup drms_segment_lookupnum drms_segment_print drms_segment_read drms_segment_readslice drms_segment_segsmatch drms_segment_setblocksize drms_segment_setdims drms_segment_size drms_segment_write drms_segment_write_from_file drms_segment_writeslice name2seg num2seg

int drms_segment_write ( DRMS_Segment_t *  seg, DRMS_Array_t *  arr, int  autoscale   ) Writes the data from the DRMS array arr into the file associated with the segment seg, provided that the segment uses one of the supported non-ready-only protocols (DRMS_BINARY, DRMS_BINZIP, DRMS_FITS, DRMS_FITZ, and DRMS_TAS). The array dimensions must match those of the segment. If autoscale is non-zero, the function drms_segment_autoscale is invoked before output. seg and arr both contain bzero and bscale fields. If seg->bzero is not 0 or seg->bscale is not 1, then the data file contains values in "scaled units" (the original values, which were in "physical units", have been scaled and an offset has been applied). The meaning of arr->bzero and arr->bscale depends on whether arr->type is a floating-point type or not, and whether arr->israw is 1 or not. When arr->type is a floating-point data type, then the data values in arr->data are assumed to be in physical units and arr->israw is ignored. But when arr->type is an integer data type, then arr->data may be in either physical or scaled units. If arr->israw is 1, then the values in arr->data are in scaled units, and if arr->israw is 0, then arr->data values are in physical units. Depending on arr->type, arr->israw, and seg->type drms_segment_write will scale (apply arr->bzero and arr->bscale), inverse scale (apply -arr->bzero / arr->bscale and 1.0 / arr->bscale), or data-type convert the data values in arr->data before writing the values to disk. Scaling is the process of converting from values in scaled units to values in physical units. Inverse scaling is the opposite process: converting from physical units to scaled units. Inverse scaling simply scales floating-point values into integers such that applying arr->bzero and arr->bscale to these integers reconstructs the original floating-point data values. Data-type conversion converts from one data type to another. For example, if the conversion is from an integer to a float, then an original value of 23.7 would round to 24. Data-type conversion always happens when arr->type does not equal seg->type. If the data values are in physical units (either floating-point data, or arr->israw is 0) and seg->type is a floating-point type, then no scaling occurs. If the data values are in physical units and seg->type is an integer type, then the caller can specify whether or not inverse scaling should occur. If arr->bzero is 0 and arr->bscale is 1, then no inverse scaling will occur and the data file will contain values in physical units. If arr->bzero is not 0 or arr->bscale is not 1, then inverse scaling will occur. If the data values are in scaled units (arr->israw is 1 and arr->type is an integer type) and seg->type is a floating-point type, then scaling occurs and data values are stored in physical units. If the data values are in scaled units and seg->type is an integer type, then no scaling occurs. Parameters: seg  The segment whose file is to be written to the filesystem. arr  The array containing the data that is to be written to the output file. autoscale  If 0, do not invoke drms_segment_autoscale. Otherwise, invoke drms_segment_autoscale. Returns: DRMS status (see drms_statuscodes.h). 0 if successful, non-0 otherwise. Definition at line 2055 of file drms_segment.c.