# Examples for backend: qwt

- Supported arguments: `annotation`, `args`, `axis`, `background_color`, `color`, `fillto`, `foreground_color`, `group`, `heatmap_c`, `kwargs`, `label`, `layout`, `legend`, `linestyle`, `linetype`, `marker`, `markercolor`, `markersize`, `n`, `nbins`, `nc`, `nr`, `pos`, `reg`, `show`, `size`, `title`, `width`, `windowtitle`, `x`, `xlabel`, `y`, `ylabel`, `yrightlabel`
- Supported values for axis: `:auto`, `:left`, `:right`
- Supported values for linetype: `:none`, `:line`, `:path`, `:steppre`, `:steppost`, `:sticks`, `:scatter`, `:heatmap`, `:hexbin`, `:hist`, `:bar`
- Supported values for linestyle: `:auto`, `:solid`, `:dash`, `:dot`, `:dashdot`, `:dashdotdot`
- Supported values for marker: `:none`, `:auto`, `:rect`, `:ellipse`, `:diamond`, `:utriangle`, `:dtriangle`, `:cross`, `:xcross`, `:star1`, `:star2`, `:hexagon`
- Is `subplot`/`subplot!` supported? Yes

### Initialize

```julia
using Plots
qwt()
```

### Lines

A simple line plot of the columns.

```julia
plot(rand(50,5),w=3)
```

![](../img/qwt/qwt_example_1.png)

### Functions

Plot multiple functions.  You can also put the function first.

```julia
plot(0:0.01:4π,[sin,cos])
```

![](../img/qwt/qwt_example_2.png)

### 

You can also call it with plot(f, xmin, xmax).

```julia
plot([sin,cos],0,4π)
```

![](../img/qwt/qwt_example_3.png)

### 

Or make a parametric plot (i.e. plot: (fx(u), fy(u))) with plot(fx, fy, umin, umax).

```julia
plot(sin,(x->begin  # /home/tom/.julia/v0.4/Plots/docs/example_generation.jl, line 33:
            sin(2x)
        end),0,2π,legend=false,fillto=0)
```

![](../img/qwt/qwt_example_4.png)

### Global

Change the guides/background/limits/ticks.  You can also use shorthand functions: `title!`, `xlabel!`, `ylabel!`, `xlims!`, `ylims!`, `xticks!`, `yticks!`

```julia
plot(rand(10),title="TITLE",xlabel="XLABEL",ylabel="YLABEL",background_color=RGB(0.2,0.2,0.2),xlim=(-3,13),yticks=0:0.1:1)
```

![](../img/qwt/qwt_example_5.png)

### Two-axis

Use the `axis` arguments.

Note: Currently only supported with Qwt and PyPlot

```julia
plot(Vector[randn(100),randn(100) * 100]; axis=[:l,:r],ylabel="LEFT",yrightlabel="RIGHT")
```

![](../img/qwt/qwt_example_6.png)

### Vectors w/ pluralized args

Plot multiple series with different numbers of points.  Mix arguments that apply to all series (singular... see `marker`) with arguments unique to each series (pluralized... see `colors`).

```julia
plot(Vector[rand(10),rand(20)]; marker=:ellipse,markersize=8,c=[:red,:blue])
```

![](../img/qwt/qwt_example_7.png)

### Build plot in pieces

Start with a base plot...

```julia
plot(rand(100) / 3,reg=true,fillto=0)
```

![](../img/qwt/qwt_example_8.png)

### 

and add to it later.

```julia
scatter!(rand(100),markersize=6,c=:blue)
```

![](../img/qwt/qwt_example_9.png)

### Heatmaps



```julia
heatmap(randn(10000),randn(10000),nbins=100)
```

![](../img/qwt/qwt_example_10.png)

### Line types



```julia
types = intersect(supportedTypes(),[:line,:path,:steppre,:steppost,:sticks,:scatter])
n = length(types)
x = Vector[sort(rand(20)) for i = 1:n]
y = rand(20,n)
plot(x,y,t=types,lab=map(string,types))
```

![](../img/qwt/qwt_example_11.png)

### Line styles



```julia
styles = setdiff(supportedStyles(),[:auto])
plot(cumsum(randn(20,length(styles)),1); style=:auto,label=map(string,styles),w=5)
```

![](../img/qwt/qwt_example_12.png)

### Marker types



```julia
markers = setdiff(supportedMarkers(),[:none,:auto])
scatter(0.5:9.5,[fill(i - 0.5,10) for i = length(markers):-1:1]; marker=:auto,label=map(string,markers),ms=10)
```

![](../img/qwt/qwt_example_13.png)

### Bar

x is the midpoint of the bar. (todo: allow passing of edges instead of midpoints)

```julia
bar(randn(1000))
```

![](../img/qwt/qwt_example_14.png)

### Histogram



```julia
histogram(randn(1000),nbins=50)
```

![](../img/qwt/qwt_example_15.png)

### Subplots

  subplot and subplot! are distinct commands which create many plots and add series to them in a circular fashion.
  You can define the layout with keyword params... either set the number of plots `n` (and optionally number of rows `nr` or 
  number of columns `nc`), or you can set the layout directly with `layout`.


```julia
subplot(randn(100,5),layout=[1,1,3],t=[:line,:hist,:scatter,:step,:bar],nbins=10,leg=false)
```

![](../img/qwt/qwt_example_16.png)

### Adding to subplots

Note here the automatic grid layout, as well as the order in which new series are added to the plots.

```julia
subplot(randn(100,5),n=4)
```

![](../img/qwt/qwt_example_17.png)

### 



```julia
subplot!(randn(100,3))
```

![](../img/qwt/qwt_example_18.png)