Merge pull request #760 from JuliaControl/rlocfix

Include zeros when calculating lims for rlocus

Author: baggepinnen

docs/src/examples/example.md

@@ -4,8 +4,8 @@ DocTestSetup = quote
     plotsDir = joinpath(dirname(pathof(ControlSystems)), "..", "docs", "build", "plots")
     mkpath(plotsDir)
     nyquistplot(ssrand(1,1,1)) # to get the warning for hover already here
-    save_docs_plot(name) = Plots.savefig(joinpath(plotsDir,name))
-    save_docs_plot(p, name) = Plots.savefig(p, joinpath(plotsDir,name))
+    save_docs_plot(name) = (Plots.savefig(joinpath(plotsDir,name)); nothing)
+    save_docs_plot(p, name) = (Plots.savefig(p, joinpath(plotsDir,name)); nothing)
 end
 ```
 

src/root_locus.jl

@@ -62,9 +62,11 @@ rlocusplot
     roots, K = getpoles(P,K)
     redata = real.(roots)
     imdata = imag.(roots)
+    all_redata = [vec(redata); real.(Z)]
+    all_imdata = [vec(imdata); imag.(Z)]
 
-    ylims --> (max(-50,minimum(imdata) - 1), min(50,maximum(imdata) + 1))
-    xlims --> (max(-50,minimum(redata) - 1), clamp(maximum(redata) + 1, 1, 50))
+    ylims --> (max(-50,minimum(all_imdata) - 1), min(50,maximum(all_imdata) + 1))
+    xlims --> (max(-50,minimum(all_redata) - 1), clamp(maximum(all_redata) + 1, 1, 50))
     framestyle --> :zerolines
     title --> "Root locus"
     xguide --> "Re(roots)"