Two Y axes not lining up (semilogx for one, line for the other)

Hi there,

I have two sets of axes set up. On the first (left Y and bottom X) I am plotting a "semilogx" function to plot. On the second set of axes (right Y and top X) I am simply using a "line" function to plot. The tick marks are set up the same on both (except that I manually changed the labels for the right Y axis) - they should be at 800, 600, 400, 200. The two Y axis tick marks line up fine when I am using a simple "line" function for the first set of axes. BUT when I use a "semilogx" function, for some reason the right Y axis gets these odd misalignments. Here is a sample:

http://www.aaronburdick.com/Other/Randomfor-personal-use/18570968_kxb4jj#1504207519_P4s68jn-A-LB

Any help would be appreciated!

Thank you!

Aaron

[Aaron Burdick]

Here's the code I'm using:

hl1 = semilogx(basinput,bas_hpa,'Color',[0 0 0],'linewidth',2);

ax1 = gca;

set(ax1,'XColor',[0 0 0],'YColor',[0 0 0],'Parent',figure1,'YTickLabel',{'200','400','600','800','1000'},...

'YTick',[200 400 600 800 1000],...

'YMinorTick','on',...

'YDir','reverse',...

'XMinorTick','on',...

'Position',[0.13 0.112403846153846 0.710158478605388 0.793461538461539],...

'FontSize',16,...

'FontName','Times');

axis tight;

THEN LATER FOR THE LINE GRAPH:

ax2 = axes('Position',get(ax1,'Position'),...

'XAxisLocation','top',...

'YAxisLocation','right',...

'YTick',[200 400 600 800 1000],...

'YTickLabel',{'11.8','7.18','4.20','1.95',''},...

'YMinorTick','off',...

'XMinorTick','on',...

'YDir','reverse',...

'FontSize',16,...

'FontName','Times',...

'Position',[0.13 0.112403846153846 0.710158478605388 0.793461538461539],...

'Color','none',...

'XColor','k','YColor','k');

hl2 = line(difpercent,dif_hpa,'Parent',ax2,'Color',[0 0 0],...

'linewidth',2,'linestyle',':');

Answer 1

[Walter Roberson]

For this kind of plotting, one would normally use plotyy(), specifying the plotting functions to use:

plotyy(x1,y1,x2,y2,@semilogy,@plot)

[Aaron Burdick]

Would that also allow for two X axes as well as two Y axes?

[Walter Roberson]

Yes: you can set the XAxisLocation property for one of the axes to 'top', and you can set its XTick and XTickLabel at will.

[Aaron Burdick]

Hi Walter. Thanks for your help on this. I switched to plotyy function and reprogrammed based on this. But I am still getting the same misalignment in Y axes as I was getting before. Here is the code:

% Create figure

figure1 = figure('XVisual','','Color',[1 1 1]);

% Create difpercent vector

difpercent = (difinput./basinput).*100;

% plotyy graph

[AX,H1,H2] = plotyy(basinput,bas_hpa,difpercent,dif_hpa,@semilogx,@plot)

set(AX(1),'XColor',[0 0 0],'YColor',[0 0 0],'Parent',figure1,...

'YTickLabel',{'200','400','600','800','1000'},...

'YTick',[200 400 600 800 1000],...

'YMinorTick','on',...

'YDir','reverse',...

'XMinorTick','on',...

'Position',[0.13 0.112403846153846 0.710158478605388 0.793461538461539],...

'FontSize',16,...

'FontName','Times');

set(H1,'Color',[0 0 0],'linewidth',2)

axis tight;

legend([,units,],'%','Location','Best')

% Create ylabel

ylabel('Pressure (hPa)','FontWeight','bold','FontSize',18,...

'FontName','Times');

% Create xlabel

xlabel([,xaxistitle,],'FontWeight','bold','FontSize',18,...

'FontName','Times');

set(AX(2),'XAxisLocation','top',...

'YAxisLocation','right',...

'YTick',[200 400 600 800 1000],...

'YTickLabel',{'11.8','7.18','4.20','1.95',''},...

'YMinorTick','off',...

'XMinorTick','on',...

'YDir','reverse',...

'FontSize',16,...

'FontName','Times',...

'Position',[0.13 0.112403846153846 0.710158478605388 0.793461538461539],...

'Color','none',...

'XColor','k','YColor','k');

set(get(AX(2),'Ylabel'),'String','Altitude (km)','FontWeight','bold',...

'FontSize',18,...

'FontName','Times');

set(get(AX(2),'Xlabel'),'String',[,x2axistitle,],'FontWeight','bold',...

'FontSize',18,...

'FontName','Times');

set(H2,'Color',[0 0 0],'linewidth',2,'linestyle',':')

% Set output size

set(gcf, 'units', 'pixels');

set(gcf, 'position', [200 150 650 550]);

Any idea why the Y axes would not be lining up? They are the same values, just labeled differently for the right Y axes (matching up km to pressure).

Thank you!

Aaron