How to access second axes in the PLOTYY syntax?

Dear all,

This thread is a continuation from the following thread_1. Thanks to Walter for suggesting the code in the thread.

The idea was to add different XTickLabel at the second axes (i.e., ax(2)), specifically to change the label at the bottom X-axis into a set of number. I tried to access the second axis by plugging ax(2), but nothing is changing!.

Similarly, I want to add more instead of default one thicklabel at the second Y-axis. I assume, this too can be done by accessing the second axis.

Here is the code and some illustrative figure to show the intended objective.

Figure

ax = plotyy(st_X_hour, st_Vec_Y1_mean, st_X_hour, st_Y2, @(x,y) errorbar(x, y, st_Vec_Y1_Sd, '--x', 'MarkerSize', 15), @(x,y) plot(x, y, 'k') );
set(ax(1), 'Xtick', st_Xaxis_intrmit, 'XTickLabel',st_XLabel,'XAxisLocation','top');
xtickangle(ax(1), 90);
ylim(ax(1),[0.5 5.5])
nox=273:20:400;
set(ax(2), 'Xtick', nox, 'XTickLabel',1:numel(nox),'XAxisLocation','bottom');

Thanks in advance!

Answer 1

[per isakson]

plotyy returns a vector of two axis-handles. (The diagram (before HG2 and I guess in HG2) was two plots on top of each other.)

• Look up Tick Values and Labels AND Grid Lines in the documentation.
• Assign appropriate values to the appropriate properties.

>> ax = plotyy( (1:3), ones(1,3), (1:3),2*ones(1,3))
ax = 
  1x2 Axes array:

      Axes    Axes
  >> ax(1)
  ans = 
    Axes with properties:

               XLim: [1 3]
               YLim: [0 2]
             XScale: 'linear'
             YScale: 'linear'
      GridLineStyle: '-'
           Position: [0.1300 0.1100 0.7750 0.8150]
              Units: 'normalized'

Show all properties

>> struct(ax(1))
Warning: .... 
ans = 
                            CameraPosition: [2 1 17.3205]
                        CameraPositionMode: 'auto'
                          CameraPosition_I: [2 1 17.3205]
                              CameraTarget: [2 1 0]
                          CameraTargetMode: 'auto'
                            CameraTarget_I: [2 1 0]
                            CameraUpVector: [0 1 0]
                             .............

And with a tool under development

>> dbnv( ax(1), 'YTick' )
                     YTick: [0 0.5000 1 1.5000 2]
                   YTick_I: [0 0.5000 1 1.5000 2]
                YTickLabel: {5x1 cell}
              YTickLabel_I: {5x1 cell}
            YTickLabelMode: 'auto'
        YTickLabelRotation: 0
      YTickLabelRotation_I: 0
    YTickLabelRotationMode: 'auto'
               YTickLabels: {5x1 cell}
           YTickLabels_I: {5x1 cell}
         YTickLabelsMode: 'auto'
               YTickMode: 'manual'

I'll first fix a problem, then I attach the function, dbnv

[per isakson]

Here is the function, dbnv. It spits out a warning despite I have set the warning off.

The EraseMode property is no longer supported and will error in a future release.
id =
MATLAB:hg:EraseModeIgnored
>> dbnv( ax(1), 'YTick' )
85      opc = warning_off({
Warning: The DrawMode property will be removed in a future release. Use the SortMethod property instead. 
> In dbnv>struct_array_ (line 134)
  In dbnv (line 91) 
Warning: The DrawMode property will be removed in a future release. Use the SortMethod property instead. 
> In dbnv>struct_array_ (line 137)
  In dbnv (line 91) 
>> warning('query', 'MATLAB:hg:EraseModeIgnored' )
The state of warning 'MATLAB:hg:EraseModeIgnored' is 'off'.

[balandong]

Hi Per, Thanks for the reply. I tried to change the bottom X-axis with the following code, but I cant see any changes. I am using 2017a. In addition, I am still vague on how to use the DBNV function. Really appreciate if you can shed some light.

Thank you

ax = plotyy(st_X_hour, st_Vec_Y1_mean, st_X_hour, st_Y2, @(x,y) errorbar(x, y, st_Vec_Y1_Sd, '--x', 'MarkerSize', 15), @(x,y) plot(x, y, 'k') );
set(ax(1), 'Xtick', st_Xaxis_intrmit, 'XTickLabel',st_XLabel,'XAxisLocation','top');
xtickangle(ax(1), 90);
ylim(ax(1),[0.5 5.5])
set(ax(2),'XAxisLocation','bottom');
ax(2).XTick = [200 300];
ax(2).XTickLabel = [200 300];