07/10/2016

25 days ago

125 commits

This package contains many statistical recipes for concepts and types introduced in the JuliaStats organization, intended to be used with Plots.jl:

- Types:
- DataFrames (for DataTables support, checkout the
`DataTables`

branch) - Distributions

- DataFrames (for DataTables support, checkout the
- Recipes:
- histogram/histogram2d
- boxplot
- violin
- marginalhist
- corrplot/cornerplot

Initialize:

```
#Pkg.clone("git@github.com:JuliaPlots/StatPlots.jl.git")
using StatPlots
gr(size=(400,300))
```

The `DataFrames`

support allows passing `DataFrame`

columns as symbols. Operations on DataFrame column can be specified using quoted expressions, e.g.

```
using DataFrames
df = DataFrame(a = 1:10, b = 10*rand(10), c = 10 * rand(10))
plot(df, :a, [:b :c])
scatter(df, :a, :b, markersize = :(4 * log(:c + 0.1)))
```

If you find an operation not supported by DataFrames, please open an issue. An alternative approach to the `StatPlots`

syntax is to use the DataFramesMeta macro `@with`

. Symbols not referring to DataFrame columns must be escaped by `^()`

e.g.

```
using DataFramesMeta
@with(df, plot(:a, [:b :c], colour = ^([:red :blue])))
```

```
using RDatasets
iris = dataset("datasets","iris")
marginalhist(iris, :PetalLength, :PetalWidth)
```

```
M = randn(1000,4)
M[:,2] += 0.8sqrt(abs(M[:,1])) - 0.5M[:,3] + 5
M[:,3] -= 0.7M[:,1].^2 + 2
corrplot(M, label = ["x$i" for i=1:4])
```

```
cornerplot(M)
```

```
cornerplot(M, compact=true)
```

```
import RDatasets
singers = RDatasets.dataset("lattice","singer")
violin(singers,:VoicePart,:Height,marker=(0.2,:blue,stroke(0)))
boxplot!(singers,:VoicePart,:Height,marker=(0.3,:orange,stroke(2)))
```

```
using Distributions
plot(Normal(3,5), fill=(0, .5,:orange))
```

```
dist = Gamma(2)
scatter(dist, leg=false)
bar!(dist, func=cdf, alpha=0.3)
```

```
groupedbar(rand(10,3), bar_position = :stack, bar_width=0.7)
```

This is the default:

```
groupedbar(rand(10,3), bar_position = :dodge, bar_width=0.7)
```

There is a groupapply function that splits the data across a keyword argument "group", then applies "summarize" to get average and variability of a given analysis (density, cumulative and local regression are supported so far, but one can also add their own function). To get average and variability there are 3 ways:

`compute_error = (:across, col_name)`

, where the data is split according to column`col_name`

before being summarized.`compute_error = :across`

splits across all observations. Default summary is`(mean, sem)`

but it can be changed with keyword`summarize`

to any pair of functions.`compute_error = (:bootstrap, n_samples)`

, where`n_samples`

fake datasets distributed like the real dataset are generated and then summarized (nonparametric bootstrapping).`compute_error = :bootstrap`

defaults to`compute_error = (:bootstrap, 1000)`

. Default summary is`(mean, std)`

. This method will work with any analysis but is computationally very expensive.`compute_error = :none`

, where no error is computed or displayed and the analysis is carried out normally.

The local regression uses Loess.jl and the density plot uses KernelDensity.jl. In case of categorical x variable, these function are computed by splitting the data across the x variable and then computing the density/average per bin. The choice of continuous or discrete axis can be forced via `axis_type = :continuous`

or `axis_type = :discrete`

Example use:

```
using DataFrames
import RDatasets
using StatPlots
gr()
school = RDatasets.dataset("mlmRev","Hsb82");
grp_error = groupapply(:cumulative, school, :MAch; compute_error = (:across,:School), group = :Sx)
plot(grp_error, line = :path)
```

Keywords for loess or kerneldensity can be given to groupapply:

```
df = groupapply(:density, school, :CSES; bandwidth = 1., compute_error = (:bootstrap,500), group = :Minrty)
plot(df, line = :path)
```

The bar plot

```
pool!(school, :Sx)
grp_error = groupapply(school, :Sx, :MAch; compute_error = :across, group = :Minrty)
plot(grp_error, line = :bar)
```