Yes, sure! The model is based on the simulation models DSSAT (Jones et al., 2003) and APSIM (Keating et al., 2003), which are widely used in agriculture, albeit fully deterministic (Fig. 1 from Salmerón and Purcell, 2016, is also useful). With the current model I wanted to recreate the sub-rutine that simulates phenology but make it hierarchical-- that is, instead of a separate deterministic dynamic model per soybean genotype, a unique hierarchical dynamic model modeling many genotypes at the same time. This prologue is just to let you know that most of the parameters are known from the previous simulation models. Although I may have exaggerated the uncertainty of the priors expecting the model to rely more on the data. Perhaps this is not right and stronger priors are needed?
For the parameters I know their lower and upper limits, and if we were to put uniform priors on them these would be:
target += uniform_lpdf(b_dOptFiFl | 8, 16); target += uniform_lpdf(b_dOptFlSd | 11, 17); target += uniform_lpdf(b_dOptSdPm | 29, 38); target += uniform_lpdf(b_Pcrit | 11.5, 14.5); target += uniform_lpdf(b_Psen | 0.13, 0.35);
In summary, perhaps the original priors that I proposed are too vague?
Jones, J.W., Hoogenboom, G., Porter, C.H., Boote, K.J., Batchelor, W.D., Hunt, L.A., Wilkens, P.W., Singh, U., Gijsman, A.J., Ritchie, J.T., 2003. The DSSAT cropping system model. European Journal of Agronomy, Modelling Cropping Systems: Science, Software and Applications 18, 235–265. https://doi.org/10.1016/S1161-0301(02)00107-7
Keating, B.A., Carberry, P.S., Hammer, G.L., Probert, M.E., Robertson, M.J., Holzworth, D., Huth, N.I., Hargreaves, J.N., Meinke, H., Hochman, Z., 2003. An overview of APSIM, a model designed for farming systems simulation. European Journal of Agronomy 18, 267–288.
Salmerón, M., Purcell, L.C., 2016. Simplifying the prediction of phenology with the DSSAT-CROPGRO-soybean model based on relative maturity group and determinacy. Agricultural Systems 148, 178–187. https://doi.org/10.1016/j.agsy.2016.07.016