On 12/8/20 9:43 AM, Marina Pastor wrote:
Dear all,
I have to obtain the equation of a GLMM. I hoped to do it using the
equatiomatic package, but it does not generate the equations for
GLMM. Any other package to generate it?
I have two different GLMMs:
- For the first one (glmer.nb(Zooplankton ~ offset(filtered volume)
+ Temp + Sal + (1|stationNumber), data)) I think I managed to
generate the equation manually (the coefficients are below), but
what I should add as offset?
The equation: Y = 20.57 + 1.17 Temp -2.12 Sal +ai
ai ~ N(0, 1.32^2)
The coefficients:
Random effects:
?Groups??????? Name??????? Variance Std.Dev.
?stationNumber (Intercept) 1.702??? 1.324
Number of obs: 72, groups:? stationNumber, 72
Fixed effects:
??????????? Estimate Std. Error z value Pr(>|z|)
(Intercept)? 20.5694??? 12.6924?? 2.182? 0.00146 **
Temp????????? 1.1716???? 0.2222?? 3.823 2.41e-05 ***
Sal????????? -2.1222???? 0.3710? -6.450 4.04e-05 ***
---
Signif. codes:? 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
(1) You could always run the same model with lmer() and run the
results through equatiomatic: that would tell you the equation of
the *linear predictor*. You could combine that with the results of
running equatiomatic on the model _without_ the random effect in
MASS::glm.nb and running that through equatiomatic as well.
(2) the offset is simply added to the RHS of the equation
(3) You almost certainly want to be using log(filtered volume)
rather than filtered volume itself as your offset.
Suggestion 1 should work for your other equation as well ...
- For the other GLMM (glmer.nb(Zooplankton ~ offset(filtered
volume) + Light * Depth + (1|stationNumber), data)), how can I
generate the equation? What to put as offset?
The coefficients are:
Random effects:
?Groups? Name??????? Variance Std.Dev.
?Station (Intercept) 1.865??? 1.365
Number of obs: 102, groups:? Station, 51
Fixed effects:
??????????????????????????? Estimate Std. Error? z value Pr(>|z|)
(Intercept)???????????????? -2.31986??? 0.53036 -32.290? < 2e-7 ***
Light_2N??????????????????? -0.24249??? 0.03018?? -2.852 0.000117 ***
FIni_Depth_Net_m25?????????? 1.46617??? 0.35821??? 0.301 0.193128
Light_2N:FIni_Depth_Net_m25? 1.07005??? 0.66873??? 1.095 0.001965 **
---
Signif. codes:? 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
Many thanks in advance for your time and help,
All the best!
Marina Pastor