Function to produce plots of the distribution of the standardized mean difference

```
plot_smd(
d,
df,
lambda = NULL,
sigma = NULL,
smd_ci = c("goulet", "nct", "t", "z"),
smd_label = "SMD",
type = c("c", "cd"),
levels = c(0.5, 0.9, 0.95, 0.999)
)
```

## Arguments

- d
Estimate of the standardized mean difference

- df
degrees of freedom for the standardized mean difference

- lambda
The non-centrality parameter for the standardized mean difference

- sigma
The standard error for the standardized mean difference

- smd_ci
Method for calculating SMD confidence intervals. Methods include Goulet, noncentral t (nct), central t (t), and normal method (z).

- smd_label
Label for the x-axis indicating the SMD measure

- type
Choose whether to plot a "consonance" function ("c"), consonance density ("cd"), or both (c("c","cd"); default option).

- levels
Numeric vector of confidence levels to display

## Value

Returns plot of the distribution of the standardized mean difference.

## Details

This function was created so that users could create plots from their own SMD calculations and were inspired by the concurve R package.
The difficulty is that specific information must be past onto this function.
The calculations for the standardized mean difference can be found in the vignettes of this package.
These types of plots are discussed by Schweder T, Hjort NL. (2016, ISBN:9781316445051) and Rafi Z, Greenland S. (2020) doi:10.1186/s12874-020-01105-9.