Merge pull request #9 from SimonEnsemble/animate

Animate

docs/src/viz.md

@@ -66,4 +66,5 @@ PyPlot.matplotlib.style.use(normpath(joinpath(pathof(Controlz), "..", "hipster.m
  nyquist_diagram
  bode_plot
  root_locus
+ mk_gif
 ```

src/Controlz.jl

@@ -28,7 +28,7 @@ export
  # sim.jl
  simulate, interpolate,
  # viz.jl
- viz_response, viz_poles_and_zeros, nyquist_diagram, root_locus, bode_plot,
+ viz_response, viz_poles_and_zeros, nyquist_diagram, root_locus, bode_plot, mk_gif,
  # controlz.jl
  PController, PIController, PIDController
 end

src/viz.jl

@@ -8,13 +8,21 @@ end
 """
  viz_response(t, y, 
  plot_title="", plot_xlabel="time, t", 
- plot_ylabel="output, y(t)")
+ plot_ylabel="output, y(t)",
+ savename=nothing)
 
 plot `y` vs. `t` to visualize the response of a system to an input. typically `t` and `y` are outputs of [`simulate`](@ref).
 
+note that PyPlot.jl (matplotlib) commands can be invoked after `viz_response` to make further changes to the figure panel.
+e.g. `xlim([0, 1])` can be applied after `viz_response`.
+
 # Arguments
 * `t::Array{Float64}`: array of times
 * `y::Array{Float64}`: array of values of response variables at the corresponding times in `t`
+* `plot_title::Union{String, LaTeXString}`: title of plot
+* `plot_xlabel::Union{String, LaTeXString}`: x-label
+* `plot_ylabel::Union{String, LaTeXString}`: y-label
+* `savename::Union{Nothing, String}`: filename to save as a figure in .png format (dpi 250).
 
 # Example
 ```
@@ -28,6 +36,7 @@ function viz_response(t::Array{Float64}, y::Array{Float64};
  plot_title::Union{String, LaTeXString}="", 
  plot_xlabel::Union{String, LaTeXString}=L"time, $t$",
  plot_ylabel::Union{String, LaTeXString}=L"output, $y(t)$",
+ savename::Union{Nothing, String}=nothing
  )
 
  figure()
@@ -36,7 +45,13 @@ function viz_response(t::Array{Float64}, y::Array{Float64};
  ylabel(plot_ylabel)
  title(plot_title)
  draw_axes()
- tight_layout()
+ if ! isnothing(savename)
+ tight_layout()
+ if ! occursin(".png", savename)
+ savename *= ".png"
+ end
+ savefig(savename, dpi=250, format="png")
+ end
  return nothing
 end
 
@@ -137,3 +152,67 @@ function bode_plot(g::TransferFunction; log10_ω_min::Float64=-4.0, log10_ω_max
  tight_layout()
  return nothing
 end
+
+@doc raw"""
+ mk_gif(t, y, plot_title="", plot_xlabel="time, t", 
+ plot_ylabel="output, y(t)",
+ savename="response")
+
+make a .gif of the process response.
+`t` and `y` are outputs of [`simulate`](@ref).
+accepts same arguments as [`viz_response`](@ref).
+ImageMagick must be installed to create the .gif.
+the .gif is saved as a file `savename`.
+
+# Arguments
+* `t::Array{Float64}`: array of times
+* `y::Array{Float64}`: array of values of response variables at the corresponding times in `t`
+* `plot_title::Union{String, LaTeXString}`: title of plot
+* `plot_xlabel::Union{String, LaTeXString}`: x-label
+* `plot_ylabel::Union{String, LaTeXString}`: y-label
+* `savename::String`: filename to save as a .gif. .gif extension automatically appended if not provided.
+"""
+function mk_gif(t::Array{Float64}, y::Array{Float64};
+ plot_title::Union{String, LaTeXString}="",
+ plot_xlabel::Union{String, LaTeXString}=L"time, $t$",
+ plot_ylabel::Union{String, LaTeXString}=L"output, $y(t)$",
+ savename::String="response.gif"
+ )
+ if length(t) > 999
+ error("too many points and thus images; reduce the number of points")
+ end
+
+ # let matplotlib determine x, y lims:
+ plot(t, y)
+ xmin, xmax, ymin, ymax = axis()
+ close()
+
+ # name to save image i as.
+ step_to_image(i::Int) = @sprintf("__y_of_t_snapshot_%03d.png", i)
+
+ # save series of images
+ for i = 2:length(t)
+ viz_response(t[1:i], y[1:i], plot_title=plot_title, plot_xlabel=plot_xlabel,
+ plot_ylabel=plot_ylabel)
+ xlim([xmin, xmax])
+ ylim([ymin, ymax])
+ tight_layout()
+ savefig(step_to_image(i), format="png", dpi=100)
+ close()
+ end
+
+ if ! occursin(".gif", savename)
+ savename *= ".gif"
+ end
+ try
+ run(`convert -delay 20 -loop 0 __y_of_t_snapshot_\*.png $savename`)
+ @info "see " * savename
+ catch
+ @warn "You must install ImageMagick for `convert` to run. Exiting..."
+ end
+
+ # clean up
+ for i = 2:length(t)
+ rm(step_to_image(i))
+ end
+end