# Julia PyPlot control parameters in multiple plot

**URL:** <https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323>\
**Category:** New to Julia\
**Created:** [July 13, 2019, 2:42pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323 "2019-07-13T14:42:47Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Luigi\_Marongiu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/luigi_marongiu/32/7909_2.png) [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Post date:** [July 13, 2019, 2:42pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/1 "2019-07-13T14:42:47Z")

</div>

Hello,  
I am creating some plot in Julia using PyPlot. How can I how can I combine plots with PyPlot?  
For instance, I would like one line in solid red the other in dotted green:

```julia
julia> x = range(0; stop=2*pi, length=1000)
0.0:0.006289474781961547:6.283185307179586

julia> y1 = sin.(3 * x + 4 * cos.(2 * x))
1000-element Array{Float64,1}:
 -0.7568024953079282
 -0.7687979429150046
 -0.7801330261327849
 -0.790830536475742
 -0.800913192079596
 -0.8104035427077365
  ⋮
 -0.6861303352619349
 -0.7017645466519309
 -0.7166271329853839
 -0.7307395907784272
 -0.7441239200875579
 -0.7568024953079278

julia> y2 = sin.(2 * x + 5 * cos.(3 * x))
1000-element Array{Float64,1}:
 -0.9589242746631385
 -0.9555431333512879
 -0.9525745225417045
 -0.9500689261982551
 -0.9480672919504057
 -0.9466011427015437
  ⋮
 -0.9795705265038878
 -0.975224815064202
 -0.9708927507542918
 -0.9666738797537784
 -0.9626578163088578
 -0.9589242746631386
julia> myPlot = plot(x, y1, x, y2, linewidth=2.0, color="green", "red", linestyle = "-", ".")
3-element Array{PyCall.PyObject,1}:
 PyObject <matplotlib.lines.Line2D object at 0x7f9b5feadbe0>
 PyObject <matplotlib.lines.Line2D object at 0x7f9b5fe7af98>
 PyObject <matplotlib.lines.Line2D object at 0x7f9b5fdc5240>
julia> xlabel("X-values")
PyObject Text(0.5, 23.52222222222222, 'X-values')
julia> ylabel("sin(x)")
PyObject Text(44.222222222222214, 0.5, 'sin(x)')
julia> title("simulation")
PyObject Text(0.5, 1.0, 'simulation')
julia> savefig("./plot.png", dpi = 100, format = "png", transparent = false)

```

But the graph is not really as I wanted:  
 ![plot](https://global.discourse-cdn.com/julialang/original/3X/4/3/43c8bb514a105b2f48ef33b58c60d843cb221910.png)  
This compared to:

```julia
julia> myPlot = plot(x, y1, x, y2, linewidth=2.0)
2-element Array{PyCall.PyObject,1}:
 PyObject <matplotlib.lines.Line2D object at 0x7f9b5ffffb70>
 PyObject <matplotlib.lines.Line2D object at 0x7f9b5fde9d68>
julia> xlabel("X-values")
PyObject Text(0.5, 23.52222222222222, 'X-values')
julia> ylabel("sin(x)")
PyObject Text(60.347222222222214, 0.5, 'sin(x)')
julia> title("simulation")
PyObject Text(0.5, 1.0, 'simulation')
julia> savefig("./plot2.png", dpi = 100, format = "png", transparent = false)

```

![plot2](https://global.discourse-cdn.com/julialang/original/3X/0/8/0887b575a66c9c4c0172ec204df652b476d1f83d.png)  
I also tried to provide arrays but it was not good:

```julia
julia> myPlot = plot(x, y1, x, y2, linewidth=2.0, color=["green", "red"], linestyle = ["-", "."])
ERROR: PyError ($(Expr(:escape, :(ccall(#= /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:44 =# @pysym(:PyObject_Call), PyPtr, (PyPtr, PyPtr, PyPtr), o, pyargsptr, kw))))) <class 'ValueError'>
ValueError("Unrecognized linestyle: ['-', '.']",)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/pyplot.py", line 2813, in plot
    is not None else {}), **kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/ __init__.py", line 1810, in inner
    return func(ax, *args, **kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_axes.py", line 1611, in plot
    for line in self._get_lines(*args, **kwargs):
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 393, in _grab_next_args
    yield from self._plot_args(this, kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 383, in _plot_args
    seg = func(x[:, j % ncx], y[:, j % ncy], kw, kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 288, in _makeline
    seg = mlines.Line2D(x, y, **kw)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/lines.py", line 381, in __init__
    self.set_linestyle(linestyle)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/lines.py", line 1101, in set_linestyle
    self._us_dashOffset, self._us_dashSeq = _get_dash_pattern(ls)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/lines.py", line 47, in _get_dash_pattern
    raise ValueError('Unrecognized linestyle: %s' % str(style))

Stacktrace:
 [1] pyerr_check at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:60 [inlined]
 [2] pyerr_check at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:64 [inlined]
 [3] macro expansion at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:84 [inlined]
 [4] __pycall!(::PyCall.PyObject, ::Ptr{PyCall.PyObject_struct}, ::PyCall.PyObject, ::PyCall.PyObject) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:44
 [5] _pycall!(::PyCall.PyObject, ::PyCall.PyObject, ::Tuple{StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1},StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1}}, ::Int64, ::PyCall.PyObject) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:29
 [6] _pycall!(::PyCall.PyObject, ::PyCall.PyObject, ::Tuple{StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1},StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1}}, ::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,Array{String,1},Array{String,1}}}}) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:11
 [7] #pycall#110(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,Array{String,1},Array{String,1}}}}, ::Function, ::PyCall.PyObject, ::Type{PyCall.PyAny}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:86
 [8] (::getfield(PyCall, Symbol("#kw##pycall")))(::NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,Array{String,1},Array{String,1}}}, ::typeof(PyCall.pycall), ::PyCall.PyObject, ::Type{PyCall.PyAny}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at ./none:0
 [9] #plot#85(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,Array{String,1},Array{String,1}}}}, ::Function, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at /home/gigiux/.julia/packages/PyPlot/cdCMF/src/PyPlot.jl:177
 [10] (::getfield(PyPlot, Symbol("#kw##plot")))(::NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,Array{String,1},Array{String,1}}}, ::typeof(plot), ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at ./none:0
 [11] top-level scope at none:0

```

How to a fine control the parameters in PyPlot?

---

<div class="post-metadata">

**Author:** ![Paul\_Soderlind](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/paul_soderlind/32/1753_2.png) [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)\
**Post date:** [July 13, 2019, 3:33pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/2 "2019-07-13T15:33:57Z")

</div>

Have a look at the examples at either  
[Plot Examples](https://gist.github.com/gizmaa/7214002)  
or  
[the Julia Plots Gallery](https://goropikari.github.io/PlotsGallery.jl/).

---

<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [July 13, 2019, 3:56pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/3 "2019-07-13T15:56:41Z")

</div>

> [@Luigi\_Marongiu](#):
>
> I am creating some plot in Julia using PyPlot. How can I how can I combine plots with PyPlot?

The easiest thing is just to call `plot` multiple times. The lines will be added to the same plot, but then you can control their properties individually.

```julia
plot(x, y1, linewidth=2.0, color="green", linestyle = "-")
plot(x, y2, linewidth=2.0, color="red", linestyle = ":")

```

---

<div class="post-metadata">

**Author:** ![Luigi\_Marongiu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/luigi_marongiu/32/7909_2.png) [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Post date:** [July 13, 2019, 4:41pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/4 "2019-07-13T16:41:42Z")

</div>

But I got:

```julia
julia> myPlot = plot(x, y1, linewidth=2.0, color="green", linestyle = "-")
1-element Array{PyCall.PyObject,1}:
 PyObject <matplotlib.lines.Line2D object at 0x7f910db93cf8>

julia> myPlot = plot(x, y2, linewidth=2.0, color="red", linestyle = ".")
ERROR: PyError ($(Expr(:escape, :(ccall(#= /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:44 =# @pysym(:PyObject_Call), PyPtr, (PyPtr, PyPtr, PyPtr), o, pyargsptr, kw))))) <class 'ValueError'>
ValueError("Invalid linestyle '.'; see docs of Line2D.set_linestyle for valid values",)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/pyplot.py", line 2813, in plot
    is not None else {}), **kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/ __init__.py", line 1810, in inner
    return func(ax, *args, **kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_axes.py", line 1611, in plot
    for line in self._get_lines(*args, **kwargs):
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 393, in _grab_next_args
    yield from self._plot_args(this, kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 383, in _plot_args
    seg = func(x[:, j % ncx], y[:, j % ncy], kw, kwargs)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/axes/_base.py", line 288, in _makeline
    seg = mlines.Line2D(x, y, **kw)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/lines.py", line 381, in __init__
    self.set_linestyle(linestyle)
  File "/home/gigiux/.local/lib/python3.6/site-packages/matplotlib/lines.py", line 1095, in set_linestyle
    .format(ls))

Stacktrace:
 [1] pyerr_check at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:60 [inlined]
 [2] pyerr_check at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:64 [inlined]
 [3] macro expansion at /home/gigiux/.julia/packages/PyCall/ttONZ/src/exception.jl:84 [inlined]
 [4] __pycall!(::PyCall.PyObject, ::Ptr{PyCall.PyObject_struct}, ::PyCall.PyObject, ::PyCall.PyObject) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:44
 [5] _pycall!(::PyCall.PyObject, ::PyCall.PyObject, ::Tuple{StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1}}, ::Int64, ::PyCall.PyObject) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:29
 [6] _pycall!(::PyCall.PyObject, ::PyCall.PyObject, ::Tuple{StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}},Array{Float64,1}}, ::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,String,String}}}) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:11
 [7] #pycall#110(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,String,String}}}, ::Function, ::PyCall.PyObject, ::Type{PyCall.PyAny}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at /home/gigiux/.julia/packages/PyCall/ttONZ/src/pyfncall.jl:86
 [8] (::getfield(PyCall, Symbol("#kw##pycall")))(::NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,String,String}}, ::typeof(PyCall.pycall), ::PyCall.PyObject, ::Type{PyCall.PyAny}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at ./none:0
 [9] #plot#85(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,String,String}}}, ::Function, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at /home/gigiux/.julia/packages/PyPlot/cdCMF/src/PyPlot.jl:177
 [10] (::getfield(PyPlot, Symbol("#kw##plot")))(::NamedTuple{(:linewidth, :color, :linestyle),Tuple{Float64,String,String}}, ::typeof(plot), ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Vararg{Any,N} where N) at ./none:0
 [11] top-level scope at none:0

julia> myPlot = plot!(x, y2, linewidth=2.0, color="red", linestyle = ".")
ERROR: UndefVarError: plot! not defined
Stacktrace:
 [1] top-level scope at none:0

julia>

```

---

<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [July 13, 2019, 5:59pm UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/5 "2019-07-13T17:59:08Z")

</div>

> [@Luigi\_Marongiu](#):
>
> `ValueError("Invalid linestyle '.' ...`)

Did you read the error message? It says exactly what your problem is: `'.'` is an invalid linestyle. If you want a dotted line, you can use `linestyle=":"`. As the message says, the valid linestyles are listed [in the `Line2D.set_linestyle` documentation, which you can easily google](https://matplotlib.org/3.1.1/api/_as_gen/matplotlib.lines.Line2D.html#matplotlib.lines.Line2D.set_linestyle).

---

<div class="post-metadata">

**Author:** ![Luigi\_Marongiu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/luigi_marongiu/32/7909_2.png) [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Post date:** [July 14, 2019, 6:34am UTC](https://discourse.julialang.org/t/julia-pyplot-control-parameters-in-multiple-plot/26323/6 "2019-07-14T06:34:09Z")

</div>

You were right, sorry. I got the linestyle = “.” probably from another plot function’s help. It worked.  
 ![plot](https://global.discourse-cdn.com/julialang/original/3X/c/c/cc1499047edccbf2167b5a122401cb1d9c679a34.png)