VamasHeader

VamasHeader

class vamas.vamas_header.VamasHeader(format_identifier: str, institution_identifier: str, instrument_model_identifier: str, operator_identifier: str, experiment_identifier: str, num_lines_comment: int, comment: Optional[str], experiment_mode: str, scan_mode: str, num_experiment_variables: int, num_entries_inclusion_exclusion: int, block_params_includes: List[bool], num_manually_entered_items_in_block: int, num_future_upgrade_experiment_entries: int, num_future_upgrade_block_entries: int, num_blocks: int, num_spectral_regions: Optional[int] = None, num_analysis_positions: Optional[int] = None, num_discrete_x_coords_in_full_map: Optional[int] = None, num_discrete_y_coords_in_full_map: Optional[int] = None, experiment_variables: Optional[List[ExperimentVariable]] = None, future_upgrade_experiment_entries: Optional[List[FutureUpgradeExperimentEntry]] = None)

Header information about a Vamas experiment

format_identifier

Format identifier. Must be ‘VAMAS Surface Chemical Analysis Standard Data Transfer Format 1988 May 4’.

Type:

str

institution_identifier

Institution identifier.

Type:

str

instrument_model_identifier

Instrumental Model Identifier.

Type:

str

operator_identifier

Operator Identifier.

Type:

str

experiment_identifier

Experiment Identifier.

Type:

str

num_lines_comment

Number of comment lines.

Type:

int

comment

Concatenated comment lines. The comment may include details of the last calibration of the instrument.

Type:

str

experiment_mode

Experiment mode. Has one of the values ‘MAP’ | ‘MAPDP’ | ‘MAPSV’ | ‘MAPSVDP’ | ‘NORM’ | ‘SDP’ | ‘SDPSV’ | ‘SEM’. The contents of each block in the experiment are indicated by the values of experiment mode as follows:

• MAP

  A spectrum which refers to a specified point in a regular two-dimensional spatial array.

• MAPDP

  A spectrum which refers to a specified point in a regular two-dimensional spatial array and to a specified layer in a depth profile.

• MAPSV

  A complete set of single values of a fixed number of variables for every point in a regular two-dimensional spatial array. Note that an x linescan consists of a map with the value of number of analysis positions equal to the value of number of discrete x coordinates available in full map, that is, the number of discrete y coordinates is unity; in a y linescan the roles of x and y are reversed.

• MAPSVDP

  A complete set of single values of a fixed number of variables for every point in a regular two-dimensional array for one layer in a depth profile. Successive blocks refer to successive layers in the depth profile.

• NORM

  Either independent data or data which refers to a specified set of single values of one or more experimental variables; the data may be spectral or non-spectral.

• SDP

  A spectrum which refers to a specified layer in a depth profile.

• SDPSV

  A complete set of single values of a fixed number of variables for every layer in a depth profile.

• SEM

  An electron emission intensity for every point in a regular two-dimensional spatial array.

Type:

str

scan_mode

Scan Mode. Has one of the values ‘REGULAR’ | ‘IRREGULAR’ | ‘MAPPING’. If the value of experiment_mode is MAPSV, MAPSVDP or SEM then the value of scan_mode must be MAPPING, otherwise if the data is in the form of an abscissa start, an abscissa increment and a number of complete sets of values of one or more experimental variables then the value of scan_mode is REGULAR, otherwise the value of scan_mode is IRREGULAR.

Type:

str

num_spectral_regions

Number of spectral regions. Normally only one technique is used in an experiment but there may be more. The value of num_spectral_regions is the sum for all techniques of the numbers of spectral regions in each technique. num_spectral_regions is inserted if and only if the value of experiment_mode is MAP, MAPDP, NORM or SDP. (optional-sequence)

Type:

int

num_analysis_positions

Number of analysis positions. Inserted if and only if the value of experiment_mode is either MAP or MAPDP. (optional-sequence)

Type:

int

num_discrete_x_coords_in_full_map

Number of discrete x coordinates available in full map. Inserted if and only if the value of experiment_mode is either MAP or MAPDP. (optional-sequence)

Type:

int

num_discrete_y_coords_in_full_map

Number of discrete y coordinates available in full map. Inserted if and only if the value of experiment_mode is either MAP or MAPDP. (optional-sequence)

Type:

int

num_experiment_variables

Number of experimental variables An experimental variable is a parameter which may be varied from block to block through the experiment but which remains constant within each block.

Type:

int

experiment_variables

Experiment variables. (optional-sequence)

Type:

Optional[List[ExperimentVariable]]

num_entries_inclusion_exclusion

Parameter inclusion or exclusion. (prefix number)

Type:

int

block_params_includes

Deteminated which parameters are included in all blocks.

Type:

List[bool]

num_manually_entered_items_in_block

Prefix number of manually entered item. The number of occurrences of prefix number of manually entered item is specified by the value of num_manually_entered_items_in_block above. If this is greater than zero then the values of successive occurrences of prefix number of manually entered item should be in ascending order. Any of the items preceded by prefix numbers in comment brackets in the syntax-rule defining block which need to be evaluated by the operator and manually entered from the keyboard should be included in this list. If an item is to be expressed as a real number and the operator is unable to supply a value then the computer should enter the value 1E37. (repeated-sequence)

Type:

int

num_future_upgrade_experiment_entries

Number of future upgrade experiment entries.

Type:

int

future_upgrade_experiment_entries

(Optional[List[FutureUpgradeExperimentEntry]]): List of future upgrade experiment entries. The number of occurrences of FutureUpgradeExperimentEntry is given by the value of num_future_upgrade_experiment_entries. It is defined as a text line so that any integer, real number or text line inserted here by a future upgrade of the format can be read as a text line then discarded. (repeated-sequence)

Type:

Optional[List[vamas.vamas_header.FutureUpgradeExperimentEntry]]

num_future_upgrade_block_entries

num_future_upgrade_experiment_entries and num_future_upgrade_block_entries are included in case the format is upgraded in the future to include more non-optional, non-repeating parameters. The numbers of these new parameters will be entered here so that old programs can skip the new parameters in new data, and new programs will not try to read the new parameters in old data. For the present both of them would be set to zero.

Type:

int

num_blocks

Number of blocks.

Type:

int

FutureUpgradeExperimentEntry

class vamas.vamas_header.FutureUpgradeExperimentEntry(label: str, unit: str)

Information about future uprade experiment entries

The number of occurrences of FutureUpgradeExperimentEntry is given by the value of num_future_upgrade_experiment_entries in VamasHeader. It is defined as a text line so that any integer, real number or text line inserted here by a future upgrade of the format can be read as a text line then discarded.

label

Type:

str

unit

Type:

str

ExperimentVariable

class vamas.vamas_header.ExperimentVariable(label: str, unit: str)

Information about a experimental variable

The number of occurrences of ExperimentVariable is specified by the value of num_experiment_variables in VamasHeader.

label

Type:

str

unit

( c/s | d | degree | eV | K | micro C | micro m | m/s | n | nA | ps | s | u | V ) These values are abbreviations for the units listed below:

c/s	counts per second
d	dimensionless - just a number, eg. counts per channel
degree	angle in degrees
eV	electron volts
K	Kelvin
micro C	microcoulombs
micro m	micrometres
m/s	metres per second
n	not defined here - may be given in a label
nA	nanoamps
ps	picoseconds
s	seconds
u	unified atomic mass units
V	volts

Type:

str