# \[ANN\] Metida.jl: mixed-effects models fitting package

**URL:** https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723
**Category:** Package Announcements
**Tags:** package, announcement, statistics
**Created:** [February 6, 2021, 8:58am UTC](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723 "2021-02-06T08:58:04Z")
**Posts on this page:** 4
**Page:** 2

<div class="post-metadata">

### Author: ![Jefferson\_Paril](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jefferson_paril/32/10314_2.png) [@Jefferson\_Paril](https://discourse.julialang.org/u/Jefferson_Paril)
#### Post date: [December 16, 2024, 11:31pm UTC](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723/22 "2024-12-16T23:31:10Z")

</div>

Is the unstructure covariance structure the same as in [MixedModels.jl](https://juliastats.org/MixedModels.jl/stable/) without `zerocorr()`?

---

<div class="post-metadata">

### Author: ![PharmCat](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pharmcat/32/6953_2.png) [@PharmCat](https://discourse.julialang.org/u/PharmCat)
#### Post date: [December 17, 2024, 12:04am UTC](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723/23 "2024-12-17T00:04:07Z")

</div>

Yes:

```julia
using Metida, CSV, DataFrames, CategoricalArrays, MixedModels;
rds2 = CSV.File(joinpath(dirname(pathof(Metida)), "..", "test", "csv", "ftdf3.csv"); types = [String, Float64, Float64, String, String, String, String, String, Float64]) |> DataFrame

```

**MixedModels** :

```julia
mm = fit(MixedModel, @formula(response ~ factor+ (0+r1|subject)), rds2, REML = true)

```

```julia
Linear mixed model fit by REML
 response ~ 1 + factor + (0 + r1 | subject)
 REML criterion at convergence: 705.3822336725552

Variance components:
         ColumnVariance Std.Dev. Corr.
subject r1: A 8.51765 2.91850
         r1: B 12.72191 3.56678 +0.46
         r1: C 21.13547 4.59733 +0.46 +0.58
Residual 1.01648 1.00820
 Number of obs: 168; levels of grouping factors: 24

  Fixed-effects parameters:
──────────────────────────────────────────────────
                Coef. Std. Error z Pr(>|z|)
──────────────────────────────────────────────────
(Intercept) 40.1983 0.79166 50.78 <1e-99
factor -11.0272 1.11958 -9.85 <1e-22
──────────────────────────────────────────────────

```

**Metida** :

```julia
lmm = Metida.LMM(@formula(response~factor), rds2;
    random = Metida.VarEffect(Metida.@covstr(r1|subject), UN),
    )
Metida.fit!(lmm)

```

```julia
Linear Mixed Model: response ~ factor
Random 1:
    Model: r1|subject
    Type: UN (6), Subjects: 24
Repeated: 
    Residual only
Blocks: 24, Maximum block size: 7
Status: converged (No Errors)
    -2 logREML: 705.382 BIC: 741.166

    Fixed-effects parameters:
──────────────────────────────────────────────────
                Coef. Std. Error z Pr(>|z|)
──────────────────────────────────────────────────
(Intercept) 40.1983 0.791652 50.78 <1e-99
factor -11.0271 1.11956 -9.85 <1e-22
──────────────────────────────────────────────────
    Variance components:
    θ vector: [2.91848, 3.56669, 4.59709, 0.458287, 0.463127, 0.575315, 1.00823]
  Random 1 σ² r1: A var 8.51753
  Random 1 σ² r1: B var 12.7213
  Random 1 σ² r1: C var 21.1332
  Random 1 ρ: r1: A × r1: B rho 0.458287
  Random 1 ρ: r1: A × r1: C rho 0.463127
  Random 1 ρ: r1: B × r1: C rho 0.575315
  Residual σ² var 1.01653

```

---

<div class="post-metadata">

### Author: ![PharmCat](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pharmcat/32/6953_2.png) [@PharmCat](https://discourse.julialang.org/u/PharmCat)
#### Post date: [December 18, 2024, 11:43pm UTC](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723/24 "2024-12-18T23:43:11Z")

</div>

Metida 0.16.3 released.

Add covariance modificator.

With `ACOV` covariance structure it is possible to change existed covariance structure and add covariance with `AR` or `CH` pattern.

So…

```julia
LMM(@formula(response ~ 1), ftdf3;
    repeated = [VarEffect(@covstr(r1|subject), DIAG), 
                VarEffect(@covstr(1|subject), ACOV(AR))])

```

is the same as:

```julia
LMM(@formula(response ~ 1), ftdf3;
repeated = VarEffect(Metida.@covstr(r1|subject), ARH))

```

But other blocking factors can be used for covariation pattern:

```julia
LMM(@formula(response ~ 1), ftdf3;
    repeated = [VarEffect(@covstr(r1|subject), DIAG), 
                VarEffect(@covstr(1|r2), ACOV(CS))])

```

Or some complicated structures can be build by this way:

```julia
LMM(@formula(resp ~ 0 + device), devday;
    repeated = [VarEffect(Metida.@covstr(device|subj&day), UN), 
                VarEffect(Metida.@covstr(1|subj&device), ACOV(AR))])

```

see example [here](https://pharmcat.github.io/Metida.jl/dev/examples/#Aumented-covariance-(Experimental))

---

<div class="post-metadata">

### Author: ![PharmCat](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pharmcat/32/6953_2.png) [@PharmCat](https://discourse.julialang.org/u/PharmCat)
#### Post date: [May 15, 2025, 12:27am UTC](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723/25 "2025-05-15T00:27:11Z")

</div>

Metida 0.17.0 released.

- Rank deficient fixed effect models can be fitted.
- Minimal changes in LMM structure.
- No changes in public API.

[Previous page](https://discourse.julialang.org/t/ann-metida-jl-mixed-effects-models-fitting-package/54723.md?page=1)