# Quick hit demos

These are all miscellaneous features that may be difficult to find in other documentation.

`$`

operator for model object gets the parameter value

If our model parameters are

```
Model parameters (N=14):
name value . name value
CL 1 | SEX 0
D1 2 | SEXCL 0.7
F1 1 | SEXVC 0.85
IC50 10 | VC 20
KA 1.2 | WT 70
KIN 100 | WTCL 0.75
KOUT 2 | WTVC 1
```

we can pick a parameter value with

Or slice off multiple parameters

# Model names

For programming with a model object, we can extract the names

```
$param
[1] "CL" "VC" "KA" "F1" "D1" "WT" "SEX" "WTCL" "WTVC"
[10] "SEXCL" "SEXVC" "KIN" "KOUT" "IC50"
$init
[1] "GUT" "CENT" "RESP"
$capture
[1] "DV" "CP"
$omega
[1] "..."
$sigma
[1] "..."
$omega_labels
$omega_labels[[1]]
[1] "ECL" "EVC" "EKA" "EKOUT"
$sigma_labels
$sigma_labels[[1]]
[1] "EXPO"
```

or get all of the model elements in a list (output not shown)

# Zero all random effect variances on the fly

If your model has random effects, you can easily and temporarily zero them out.

`Building popex ... done.`

```
$...
[,1] [,2] [,3]
ECL: 0.3 0.0 0.0
EV: 0.0 0.1 0.0
EKA: 0.0 0.0 0.5
```

It is easy to simulate either with or without the random effects in the simulation: this change can be made on the fly.

Use `zero_re`

to make all random effect variances zero

By default, both `OMEGA`

and `SIGMA`

are zeroed. Check the arguments for `zero_re`

to see how to selectively zero `OMEGA`

or `SIGMA`

.

Compare the population output

with

# Plot formulae

We commonly plot simulated output with a special plot method. By default, you get all compartments and output variables in the plot.

The plot can be customized with a formula selecting variables to plot. Other arguments

to `lattice::xyplot`

can be passed as well.

# Get a data frame of simulated data

By default mrgsolve returns an object of simulated data (and other stuff)

But you can get a data frame with

or