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dvictori / learn_gr4j

Learning how to use the GR4J model implemented in python by amacd31
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Limit parameter values on optimization #8

Closed dvictori closed 6 years ago

dvictori commented 6 years ago

Place a limit on the values each parameter, so optimization does not go to far

dvictori commented 6 years ago

Table on Perrin et all (2003) mentions the median and a 80% confidence interval for parameters estimated over several watersheds. Maybe use those values as starting point and range

param median 80% interval
X1 (mm) 350 100 to 1200
X2 (mm) 0 -5 to 3
X3 (mm) 90 20 to 300
X4 (days) 1.7 1.1 to 2.9
dvictori commented 6 years ago

airGR package mentions that parameter interval in transformed parameter space should be from -9.99 to +9.99

param min max
X1 4.58e-05 21807.29
x2 -10903.6 8798230131
x3 4.58e-05 21807.29
x4 0.50004 21807.79

This range looks a bit too broad for me. Will try to use the previous 80% range first

https://cran.r-project.org/web/packages/airGR/vignettes/V02.1_param_optim.html