Zero-variate data
Zero-variate data is a scalar (so a single number) that quantifies a feature of the organism at a given moment.
Auxiliary data might be associated to any data, so also to zero-variate data.
Although a single data-point has little information for parameter estimation in itself, a set of different data-points can be very useful,
certainly in combination with uni- and bi-variate data sets.
A prediction for a zero-variate data set is typically a function of parameter values, which should be seen as removing one degree of freedom in the parameter estimation.
So with 10 parameters, 10 (independent) zero-variate data sets theoretically determine all 10 parameters.
Codification of types zero-variate data
In the mydata file the author needs to specify which types of data are used in the entry. Labels for zero-variate data are packed as metaData.data_0 in the mydata-file. The codification generally follows DEB's notation rules. The leading character indicates the type of variable, followed by a marker for the life history event.Indices symbolising different life history events
| 0 | start of development | j | end of acceleration | R | first breeding |
| h | hatching (leaving egg) | p | puberty (start of allocation to reproduction) | e | emergence (imago) |
| b | birth (start of feeding) | i | ultimate state | s | start of acceleration |
| x | weaning (or fledging) | m | death (life span) |
| f | functional response | T | temperature | t | time |
| L | length | W | weight |
The labels are stylized, meaning e.g. that label ap stands for age-at-puberty, while actually time since birth at puberty, tp, might be used as a data-point. The rationale is that delays in the start of development can occur, which would affect ap, but not tp. Data might relate to males and females; this is not indicated in the data labels, but comments in such entries specify the parameters in which they differ.
| Data labels | Description |
|---|---|
| ah | age at h |
| ah_T | age at h (several T)) |
| ab | age at birth |
| ab_T | age at birth (several T) |
| ab_f | age at birth (several f) |
| tg | gestation time |
| ax | age at x |
| as | age at s |
| aj | age at j |
| aj_T | age at j (several T) |
| ap | age (or time since birth) at p |
| ap_T | age at p (several T) |
| ap_f | age at p (several f) |
| aR | age at R |
| ae | age at e |
| astar | instar duration |
| am | age at death (life span) |
| am_f | age at death (several f) |
| am_T | age at death (several T) |
| L0 | length at 0 |
| Lh | length at h |
| Lb | length at b |
| Lb_f | length at b (several f) |
| Lx | length at x |
| Ls | length at s |
| Lj | length at j |
| Lp | length at p |
| Lp_f | length at p (several f) |
| LR | length at R |
| Lstar | length at instar |
| Li | length at i |
| Li_f | length at i (several f) |
| L_t | length at time t |
| L_W | length at time weight |
| dLb | change in length at b |
| dLp | change in length at p |
| dLj | change in length at j |
| Ab | surface area at b |
| Ap | surface area at p |
| Ai | surface area at i |
| V0 | volume at 0 |
| Vb | volume at b |
| Vb_f | volume at b (several f) |
| Vp | volume at p |
| Vp_f | volume at p (several f) |
| Vi | volume at i |
| Vi_f | volume at i (several f) |
| Ww0 | wet weight at 0 |
| Wwh | wet weight at h |
| Wwb | wet weight at b |
| Wwb_f | wet weight at b (several f) |
| Wwx | wet weight at x |
| Wws | wet weight at s |
| Wwj | wet weight at j |
| WwR | wet weight at R |
| Wwp | wet weight at p |
| Wwe | wet weight at e |
| Wwi | wet weight at i |
| Ww_L | wet weight at lenght |
| Ww_t | wet weight at time |
| dWw_W | change in wet weight at W |
| Wd0 | dry weight at 0 |
| Wdh | dry weight at h |
| Wdb | dry weight at b |
| Wdb_f | dry weight at b (several f) |
| Wdx | dry weight at x |
| Wds | dry weight at s |
| Wdj | dry weight at j |
| Wdp | dry weight at p |
| Wde | dry weight at e |
| Wdi | dry weight at i |
| Wd_t | dry weight at t |
| Wd_L | dry weight at length |
| WdR_L | gonad dry weight at L |
| WdR_Wd | gonad dry weight at Wd |
| WC0 | carbon weight at 0 |
| WN0 | nitrogen weight at 0 |
| dWdb | change in dry weight at b |
| dWd | decrease in dry weight during starvation |
| E_L | total energy at L |
| E0 | reserve energy at 0 |
| Eh | reserve energy at h |
| Eb | reserve energy at b |
| Ej | reserve energy at j |
| EbE0 | ratio of reserve energy at b and 0 |
| EXx | cumulated food energy at x |
| r | specific growth rate |
| rB | von Bertalanffy growth rate |
| rB_T | von Bertalanffy growth rate (several T) |
| Ri | reproduction rate at i |
| Ri_f | reproduction rate at i (several f) |
| R_L | reproduction rate at length |
| R_W | reproduction rate at weight |
| GSI | gonado-somatic index |
| Ni | (total) number of offspring at i |
| Ni_f | (total) number of offspring at i (several f) |
| Fm | maximum clearance (filtering) rate |
| K | half saturation coefficient |
| pXi | maximum ingestion rate (energy) |
| pXi_Wd | maximum ingestion rate at Wd (energy) |
| pX_t | food energy ingestion rate at t |
| pAi | maximum assimilation rate (energy) |
| pL | lactation flux (energy) |
| kapX | digestion efficiency |
| RQ | respiration quotient: JC/JO |
| JXi | food consumption at i |
| JX_L | food consumption at L |
| JX_W | food consumption at W |
| JLi | milk production at i |
| JOb | O2 consumption at b |
| JOi | O2 consumption at i |
| JO_W | O2 consumption at W |
| JCi | CO2 production at i |
| ss | supply stress |
| xi_WE | energy density of dry mass excluding the reproduction buffer |