Series Characteristics
Series characteristics can be added or edited in the <Series Characteristics> function of the <Entry and Edit> function group. You can either double click the <Series Characteristics> function or select the function and press <Go to Function>.
The time series characteristics that can be edited include:
- missing value,
- likely minimum and maximum value,
- lower boundary and upper boundary value (sort of secondary levels),
- likely maximum rate of rise and of fall (when relevant), and
- long time average value of the series.
- Basic time interval can be set or changed.
Remarks, giving information on the series, for example series history. Press <Add New> to add a new series, <Save> to save the entered or edited information in the database, <Delete> to delete a series from the database or <Close> to leave the window without saving.
Time labels
Special attention is given to the <Time Labels> button. This button is enabled when the basic time unit is set to cyclic . A cyclic series is a special case of an equidistant series; it is an equidistant series with "Time Labels" defining the exact measurement date/time. An example will be given.
Suppose you have two measurements a day, measured at 8:00 and 15:00. This is not exactly an equidistant series, in HYMOS it is called cyclic. You must define such a series as "time unit day, divided by 2 and basic time unit cyclic". Then press the <Time Labels> button and enter the precise times, "08:00" and "15:00" on which the measurements were taken.
Add series
When you press button <Add series> the following window will appear:
The information on your screen is built up from definition in the tabs "Station", "Time" and "Parameter". If you want different information, change your selection in those tabs or press the button <Change Selected Series ID> to change the location and parameter ID. The only option to be filled in (for equidistant time series) is the 'Basic Time Interval'. Press button <....> below the selection box of the 'Basic Time Interval'. The window "Select Basic Time Interval" appears on your screen.
Consider e.g. decade intervals, defined as Δt = (month,3). To specify that a decade consists of 10 days the basic time interval should read: basic Δt = (day,10). Then as much as possible intervals of 10 days will be defined in a month. So the first 2 decades will contain 10 days, while the last decade comprises 8, 9, 10 or 11 days depending on month and year. This leads to the following generalisation. The time interval Δt is built up out of a number of basic Δt's equal to the divider. The last time interval within a time interval unit may contain an amount of basic time interval units, that differs from the replicator. Let the time interval unit, containing n basic time interval units, be divided into k parts and let the replicator in the basic Δt be m. Then the first (k-1 ) time intervals comprise m basic Δt units. The last or k th time interval contains (n(k-1).m ) basic Δt units. If the basic Δt does not apply, then basic Δt = (0,0).
Examples
Pentad intervals: |
∆t |
|
The first 5 pentads of the month contain 5 days, while the last pentad includes 3, 4, 5 or 6 days depending on the month. |
Weekly intervals: |
Δt = (year,52) and basic Δt = (day,7). |
|
The first 51 weeks of the year contain 7 days, while the 52nd week includes 8 or 9 days. |
Note
Weekly series defined as above, Δt = (year, 52) and basic Δt = (day, 7) may differ considerably from weekly series defined with Δt = (month, 4) and basic Δt = (day, 7).
