org.das2.datum.DatumUtil
asOrderOneUnits
asOrderOneUnits( Datum d ) → Datum
This method takes the input datum and gets it as close to order one as
possible by trying all possible conversions.
Parameters
d - A datum that needs to have its units changed to order one units.
Returns:
The order-one-ified Datum.
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bestFormatter
bestFormatter( org.das2.datum.DatumVector datums ) → DatumFormatter
return the most efficient formatter for the datums, supporting
nominal data, TimeLocationUnits, and LocationUnits, and
other data.
Parameters
datums - a DatumVector
Returns:
a formatter for the set.
See Also:
https://github.com/autoplot/dev/blob/master/demos/2021/20211203/testBestFormatter.jy
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bestFormatter( org.das2.datum.DatumVector datums, DatumRange context ) → DatumFormatter
bestFormatter( Datum minimum, Datum maximum, int nsteps ) → DatumFormatter
bestTimeFormatter
bestTimeFormatter( Datum minimum, Datum maximum, int nsteps ) → DatumFormatter
Parameters
minimum - a Datum
maximum - a Datum
nsteps - an int
Returns:
org.das2.datum.format.DatumFormatter
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createValid
createValid( String s ) → Datum
create a dimensionless datum by parsing the string.
See TimeUtil.createValid( String stime ).
Parameters
s - a String
Returns:
a Datum
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datumStringSplit
datumStringSplit( String s ) → String[]
splits the datum into a magnitude part and a unit part. When times
are detected, "UTC" will be the units part.
Here is a list to test against, and the motivation:
- 2014-05-29T00:00 ISO8601 times, cannot contain spaces.
- 5.e4 Hz registered known units
- 5.6 foos units from the wild
- 5.7 bytes/sec mix of MKS and units from the wild.
- 5.7Hz no space
- 5.7T no space, contains T.
- +5.7E+2Hz more challenging double.
- $57 unit before number
Note: units cannot start with E or e then a number or plus or minus.
Datums cannot contain commas, semicolons, or quotes.
NaN is Double.NaN.
TODO: only $ is supported as a prefix. Others should be considered for
completeness.
Parameters
s - the string-formatted datum
Returns:
the magnitude and the units, or [null,s] when it is not parseable.
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divp
divp( Datum amount, Datum delta ) → Datum
this is the divide that rounds down to the next integer, so divp("-25hr","24hr") is -2.
Note that the result must be dimensionless, other forms are not supported.
TODO: study inconsistencies with QDataset Ops divp
Parameters
amount - a Datum
delta - a Datum
Returns:
the dimensionless amount.
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doubleValues
doubleValues( org.das2.datum.Datum[][] datums, Units units ) → double[]
Parameters
datums - an org.das2.datum.Datum[]
units - an Units
Returns:
double[][]
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doubleValues( org.das2.datum.Datum[][] datums, org.das2.datum.Units[][] unitsArray ) → double[]
fractionalDigits
fractionalDigits( Datum resolution ) → int
Parameters
resolution - a Datum
Returns:
int
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limitLogResolutionFormatter
limitLogResolutionFormatter( Datum minimum, Datum maximum, int nsteps ) → DatumFormatter
Parameters
minimum - a Datum
maximum - a Datum
nsteps - an int
Returns:
org.das2.datum.format.DatumFormatter
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limitResolutionFormatter
limitResolutionFormatter( Datum minimum, Datum maximum, int nsteps ) → DatumFormatter
Parameters
minimum - a Datum
maximum - a Datum
nsteps - an int
Returns:
org.das2.datum.format.DatumFormatter
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lookupDatum
lookupDatum( String s ) → Datum
Attempts to resolve strings commonly encountered. This was introduced to create a standard
method for resolving Strings in ASCII files to a Datum.
This follows the rules that:
- Things that appear to be times are parsed to a TimeLocationUnit.
- a double followed by whitespace then a unit is parsed as lookupUnit then parse(double)
Here is a list to test against, and the motivation:
- 2014-05-29T00:00 ISO8601 times, cannot contain spaces.
- 5.e4 Hz registered known units
- 5.6 foos units from the wild
- 5.7 bytes/sec mix of MKS and units from the wild.
- 5.7Hz no space
- 5.7T no space, (contains T which is also in ISO8601 times)
- 5.7eggs e could be mistaken for exponent.
- +5.7E+2Hz more challenging double.
- $57 unit before number
Parameters
s - a String
Returns:
a Datum containing the value.
See Also:
Units#parse(java.lang.String)
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modp
modp( Datum amount, Datum delta ) → Datum
return the modulo within the delta. The result will always
be a positive number. For example:
modp('-3days','7days') | 4days |
modp('10days','7days') | 3days |
A typical use might be:
%{code
t= t + modp(t-phaseStart,span)
}
TODO: study inconsistencies with QDataset Ops modp.
Parameters
amount - a Datum
delta - a Datum
Returns:
the amount.
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numericalResolutionLimit
numericalResolutionLimit( Datum datum ) → Datum
return the numeric resolution of the Datum. Note some Datum implementations
have additional information which allows the measurement resolution
to be reflected as well, and this should be much smaller.
Parameters
datum - a datum
Returns:
a datum in the offset units.
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parse
parse( String s ) → Datum
attempt to parse the string as a datum. Note that if the
units aren't specified, then of course the Datum will be
assumed to be dimensionless. This also requires the the
unit be registered already, and lookup should be used if
the unit should be registered automatically.
Strings containing the unit UTC are parsed as times.
Strings containing an ISO8601 string like $Y-$m-$dT$H:$M are parsed as strings.
Parameters
s - the string representing the Datum, e.g. "5 Hz" (but not 5Hz).
Returns:
the Datum
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parseValid
parseValid( String s ) → Datum
parse the string which contains a valid representation of a
a Datum. A runtime exception is thrown when the string
cannot be parsed.
Parameters
s - the string representing the Datum, e.g. "5 Hz"
Returns:
the Datum
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splitDatumString
splitDatumString( String s ) → String[]
Split the string to separate magnitude component from units component.
"5" → [ "5", "" ]
"5 m" → [ "5", "m" ]
"5m" → [ "5", "m" ]
"4.5m^2" → [ "4.5", "m^2" ]
"4.5e6m^2" → [ "4.5e6", "m^2" ]
"-1" → [ "-1", "" ]
"-1s" → [ "-1", "s" ]
"-1.0e-6s" → [ "-1e-6", "s" ]
"5 Deg N" → [ "5", "Deg N" ]
" 10 days" → [ "10", "days" ]
See http://jfaden.net:8080/hudson/job/autoplot-test037/ws/splitDatumString.jy
Parameters
s - the string to break up
Returns:
two element array
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zeros
zeros( int count ) → String
return "0" for 0, "0.0" for 1, "0.00" for 2, and so on. This can be used
in factory.newFormatter(formatString).
Parameters
count - number of decimal places following the decimal.
Returns:
string for newFormatter.
See Also:
DatumFormatterFactory#newFormatter(java.lang.String)
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