RCSB PDB Protein Data Bank A Member of the wwPDB
An Information Portal to Biological Macromolecular Structures
PDB Home | Dictionary Resources Home  |  Dictionary  |  Category Groups  |  Categories  |  Items  |  Data

Item _array_intensities.linearity


Description 


               The intensity linearity scaling used from raw intensity
               to the stored element value:

               'linear' is obvious

               'offset'  means that the value defined by
               '_array_intensities.offset' should be added to each
                element value.

               'scaling' means that the value defined by
               '_array_intensities.scaling' should be multiplied with each
               element value.

               'scaling_offset' is the combination of the two previous cases,
               with the scale factor applied before the offset value.

               'sqrt_scaled' means that the square root of raw
               intensities multiplied by '_array_intensities.scaling' is
               calculated and stored, perhaps rounded to the nearest
               integer. Thus, linearization involves dividing the stored
               values by '_array_intensities.scaling' and squaring the
               result.

               'logarithmic_scaled' means that the logarithm based 10 of
               raw intensities multiplied by '_array_intensities.scaling'
               is calculated and stored, perhaps rounded to the nearest
               integer. Thus, linearization involves dividing the stored
               values by '_array_intensities.scaling' and calculating 10
               to the power of this number.

               'raw' means that the data is a set of raw values straight
               from the detector.

Category

array_intensities

Mandatory Code

yes

Data Type Code

code

Enumeration Values

Item Value Description
linear n.a.
offset The value defined by '_array_intensities.offset' should be added to each element value.
scaling The value defined by '_array_intensities.scaling' should be multiplied with each element value.
scaling_offset The combination of the scaling and offset with the scale factor applied before the offset value.
sqrt_scaled The square root of raw intensities multiplied by '_array_intensities.scaling' is calculated and stored, perhaps rounded to the nearest integer. Thus, linearization involves dividing the stored values by '_array_intensities.scaling' and squaring the result.
logarithmic_scaled The logarithm based 10 of raw intensities multiplied by '_array_intensities.scaling' is calculated and stored, perhaps rounded to the nearest integer. Thus, linearization involves dividing the stored values by '_array_intensities.scaling' and calculating 10 to the power of this number.
raw The array consists of raw values to which no corrections have been applied. While the handling of the data is similar to that given for 'linear' data with no offset, the meaning of the data differs in that the number of incident photons is not necessarily linearly related to the number of counts reported. This value is intended for use either in calibration experiments or to allow for handling more complex data fitting algorithms than are allowed for by this data item.

 

© RCSB PDB