So I am encountering a couple errors and am not sure where they're coming from. I won't post the whole code, but I will do my best to explain (fear I will be accused of plagiarism).
The assignment is to create a window with two plots: a surface plot and a contour plot. The surface plot represents elevation of a portion of the map represented by the contour plot. The portion is indicated by a blue box on the contour plot. I've successfully plotted the surface and contour plots and have identified the first area with a blue box. However, now I need to implement a menu system wherein the user enters 1, 2, 3, or 4 to move the box north, south, east or west.
Here is how I instantiated the plots:
fig = figure(1);
[xGrid, yGrid] = meshgrid(xMeters(xStart:xEnd), yMeters(yStart:yEnd));
%surface plot
elevationBox = ELEV(xStart:xEnd, yStart:yEnd);
surface = subplot(2, 1, 1);
surf(xGrid, yGrid, elevationBox);
axis([0 max(xGrid(:)) 0 max(yGrid(:)) min(elevationBox(:)) max(elevationBox(:))]);
axis tight;
%contour plot
elevation = ELEV;
[xMap, yMap] = meshgrid(xMeters(1:335), yMeters(1:230));
map = subplot(2, 1, 2); contour(xMap, yMap, elevation);
axis([0 max(xMeters(:)) 0 max(yMeters(:))]);
axis fill;
set(fig, 'Position', [500 100 600 700]);
right = line(xRight, xLeft);
left = line(xLeft, yLeft);
top = line(xTop, yTop);
bottom = line(xBottom, yBottom);
So all that works fine. Obviously I didn't include the parts where I defined the data and everything. After this comes a switch statement that changes the values of xLeft, yLeft, etc as well as xStart, xEnd etc.
Here is my attempt to update the plots:
[xGrid, yGrid] = meshgrid(xMeters(xStart:xEnd), yMeters(yStart:yEnd));
elevationBox = ELEV(xStart:xEnd, yStart:yEnd);
subplot(2, 1, 1)
set(surface, 'XData', xGrid, 'YData', yGrid, 'ZData', elevationBox);
drawnow;
I can choose an option and there is no error, but the plot doesn't update and when I quit the program I get this error:
Error using matlab.graphics.axis.Axes/set
There is no XData property on the Axes class.
Error in A9 (line 129)
set(surface, 'XData', xGrid);
The setting is inside the while loop but outside the switch statement. I also had a few lines using set on the line objects but those weren't working either so I thought I'd focus here first. I'm figuring whatever I'm doing wrong applies to both object types but if not let me know.
Thanks!
Rather than grab a handle to the axis (which you call surface), you want the data object. So grab a handle at surf_h = surf(...);.
A little example:
% Generate a random surface grid
n = 10;
[x, y] = meshgrid(1:n, 1:n);
z = rand(n);
% Plot
fig_h = figure(1);
axis_h = subplot(2, 1, 1);
surf_h = surf(x,y,z);
% Modify XData
set(surf_h, 'XData', -x);
drawnow;
I'm trying to position MATLAB's ticks to line up with my grid, but I can't find a good way to offset the labels.
Also, if I run set(gca,'XTickLabel',1:10), my x tick labels end up ranging from 1 to 5. What gives?
You need to move the ticks, but get the labels before and write them back after moving:
f = figure(1)
X = randi(10,10,10);
surf(X)
view(0,90)
ax = gca;
XTick = get(ax, 'XTick')
XTickLabel = get(ax, 'XTickLabel')
set(ax,'XTick',XTick+0.5)
set(ax,'XTickLabel',XTickLabel)
YTick = get(ax, 'YTick')
YTickLabel = get(ax, 'YTickLabel')
set(ax,'YTick',YTick+0.5)
set(ax,'YTickLabel',YTickLabel)
Or if you know everything before, do it manually from the beginning:
[N,M] = size(X)
set(ax,'XTick',0.5+1:N)
set(ax,'XTickLabel',1:N)
set(ax,'YTick',0.5+1:M)
set(ax,'YTickLabel',1:M)
The marked answer works with a surf or mesh plot, however, I needed a solution which worked for a 2d plot.
This can be done by creating two axes, one to display the grid and the other to display the labels as follows
xlabels=1:1:10; %define where we want to see the labels
xgrid=0.5:1:10.5; %define where we want to see the grid
plot(xlabels,xlabels.^2); %plot a parabola as an example
set(gca,'xlim',[min(xgrid) max(xgrid)]); %set axis limits so we can see all the grid lines
set(gca,'XTickLabel',xlabels); %print the labels on this axis
axis2=copyobj(gca,gcf); %make an identical copy of the current axis and add it to the current figure
set(axis2,'Color','none'); %make the new axis transparent so we can see the plot
set(axis2,'xtick',xgrid,'XTickLabel',''); %set the tick marks to the grid, turning off labels
grid(axis2,'on'); %turn on the grid
This script displays the following figure :
I am trying to plot the wake velocity deficient behind an object at different streamwise positions (pos.1, 2 and 3) behind the object.
A rough sketch of how the graph should look like is shown below. The x-axis represents velocity and the y-axis is the coordinate normal to the flow.
How can I restart the x-axis such that the data of each position is plotted in it's own space, resembling it's actual position in the flow.
Easiest solution I think is to create all plots you need in horizontally arranged subplots, and then "beautify" according to your level of perfectionism ^_^
The "beautifications" I did in this case are:
For the axes in each subplot, switch the 'box' option off
Set the ytick to [] and color the y-axes white, of every y-axis except the leftmost one
create another axes object in the background without any axes labels, so that it appears that the subplots are really one plot
Here's the code:
%// Some bogus data
y = 0:0.1:4*pi;
x1 = sin(y);
x2 = sin(3*y);
x3 = sin(2*y).*sin(5*y);
%// Initialize figure window
figure(1), clf, hold on
%// Plot each plot on its own axes
subplot(1,3,3), hold on
plot(x3,y)
set(gca,...
'ytick' , [],...
'ycolor', 'w',...
'box' , 'off');
subplot(1,3,2)
plot(x2,y)
set(gca,...
'ytick' , [],...
'ycolor', 'w',...
'box' , 'off')
subplot(1,3,1)
plot(x1,y)
set(gca,...
'box', 'off') %// NOTE: don't kill these axes
%// Background axes
P = axes('parent', 1, 'xtick', [], 'ytick', []);
uistack(P, 'down', 10)
You could consider plotting your data on a single x-axis with an offset and changing the label of the x-axis ticks.
Consider your x-vector to be x_pos1 for the first position, your second and third would be similar but with an addition of an offset. E.g. offset = 15; x_pos2 = x_pos1+offset;
You can obtain and change your x-axis tick label by:
get(gca, 'xticklabel')
set(gca, 'xticklabel', yourLabelHere)
Is it possible to prodce a pcolor plot with 2 yaxis?
Consider the following example:
clear all
temp = 1 + (20-1).*rand(365,12);
depth = 1:12;
time =1:365;
data2 = 1 + (60-1).*rand(12,1);
time2 = [28,56,84,124,150,184,210,234,265,288,312,342];
figure;
pcolor(time,depth,temp');axis ij; shading interp
hold on
plot(time2,data2,'w','linewidth',3);
Instead of plotting the second dataset on the same y axis I would like it to placed on its own y-axis. Is this possible?
You need to add additional axes on the top of pcolor axes, match their position and then plot. You can set axes location on the top (X) and on the right (Y). Don't forget to link X axes if they suppose to match with LINKAXES.
pcolor(time,depth,temp');axis ij; shading interp
ax1 = gca;
%# new axes with plot
ax2 = axes('position',get(ax1,'position'),'color','none');
set(ax2,'YAxisLocation','right', 'XAxisLocation','top')
hold on
plot(ax2,time2,data2,'w','linewidth',3);
hold off
linkaxes([ax1 ax2], 'x');
I am not sure what you mean.
If you want same axes but different y values, try plotyy. If you want two different axes, try using the command subplot.
I'm using the following to display the minor grid in my plot:
grid(gca,'minor')
set(gca,'MinorGridLineStyle','-')
but I'd like to change the color of the grid lines to a nice greyscale. I can't find any option 'grid color' in matlab... Do you know any or any workaround?
I found this: http://www.mathworks.com/matlabcentral/fileexchange/9815-gridcolor but as I read of the comments, it doesn't work very well and further it only changes gridcolor, not the color of the minor grid...
Thanks!
EDIT:
Problem with semilogx as posting here now:
x = [1e-9 1e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2]';
y1 = linspace(20, 90, 8);
y2 = y1.^2;
y3 = y1./y2+5;
% plotte: http://www.mathworks.com/help/techdoc/ref/linespec.html
myfig = figure('Position', [500 500 445 356]); %[left, bottom, width, height]:
p1 = semilogx(x,y1,'x--r',x,y2,'*-b');
ax1 = gca;
set(ax1, 'Position',[0.13 0.18 0.75 0.75]);
xlim([0 max(x)]);
ylim([0 max([max(y1) max(y2)])]);
col=.85*[1 1 1];
%# create a second transparent axis, same position/extents, same ticks and labels
ax2 = axes('Position',get(ax1,'Position'), ...
'Color','none', 'Box','on', ...
'XTickLabel',get(ax1,'XTickLabel'), 'YTickLabel',get(ax1,'YTickLabel'), ...
'XTick',get(ax1,'XTick'), 'YTick',get(ax1,'YTick'), ...
'XLim',get(ax1,'XLim'), 'YLim',get(ax1,'YLim'),...
'XScale', 'log');
%# show grid-lines of first axis, give them desired color, but hide text labels
set(ax1, 'XColor',col, 'YColor',col, ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'MinorGridLineStyle','-', ...
'XTickLabel',[], 'YTickLabel',[],'XScale', 'log');
%# link the two axes to share the same limits on pan/zoom
linkaxes([ax1 ax2],'xy');
Displaying like this:
EDIT2: A problem occurs when adding a second y-axes as in the following picture, look at the ticks of the right y-axes:
this will be discussed here to have a better overview!
Matlab: Problem with ticks when setting minor grid style and two y-axis
Set the 'XColor','YColor' axes properties. Note that these properties determine the color of the axis lines, tick marks, tick mark labels, and the axis grid lines, so AFAIK you can't assign those different colors than that of the entire axis..
Example:
plot(rand(10,1))
set(gca, 'XMinorGrid','on', 'YMinorGrid','on', 'XColor','r', 'YColor','g')
EDIT1:
You can always create a second transparent axis with the desired grid colors, but with no ticks or labels, stacked on top of the current axis. Here is an example:
%# create plot as usual
plot(rand(10,1))
hAx1 = gca;
%# create a second axis, same position/extents, no tick or labels, colored grid-lines
hAx2 = axes('Position',get(hAx1,'Position'), ...
'Color','none', 'TickLength',[1e-100 1e-100], ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'Box','off', 'XColor','g', 'YColor','r', ...
'XTickLabel',[], 'YTickLabel',[], ...
'XTick',get(hAx1,'XTick'), 'YTick',get(hAx1,'YTick'), ...
'XLim',get(hAx1,'XLim'), 'YLim',get(hAx1,'YLim'));
%# position it on top
%#uistack(hAx2,'top')
%# redraw the enclosing box in the original axis colors
x = get(hAx1,'XLim');
y = get(hAx1,'YLim');
line([x([1 2]) nan x([2 1])],[y([1 1]) nan y([2 2])],'Color',get(hAx1,'XColor'))
line([x([1 1]) nan x([2 2])],[y([1 2]) nan y([2 1])],'Color',get(hAx1,'YColor'))
The only problem is that the grid lines are drawn on top of your plot, which might get in the way if the grid-lines are thick :)
EDIT2:
Seems like #yoda had a similar idea to the above. Here is a slightly improved version inspired by his solution:
%# create plot as usual
plot(11:20, rand(10,1)*5)
hAx1 = gca; %# get a handle to first axis
%# create a second transparent axis, same position/extents, same ticks and labels
hAx2 = axes('Position',get(hAx1,'Position'), ...
'Color','none', 'Box','on', ...
'XTickLabel',get(hAx1,'XTickLabel'), 'YTickLabel',get(hAx1,'YTickLabel'), ...
'XTick',get(hAx1,'XTick'), 'YTick',get(hAx1,'YTick'), ...
'XLim',get(hAx1,'XLim'), 'YLim',get(hAx1,'YLim'));
%# show grid-lines of first axis, give them desired color, but hide text labels
set(hAx1, 'XColor','g', 'YColor','r', ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'XTickLabel',[], 'YTickLabel',[]);
%# link the two axes to share the same limits on pan/zoom
linkaxes([hAx1 hAx2],'xy');
%# lets create a legend, and some titles
legend(hAx1, 'text')
title('title'), xlabel('x'), ylabel('y')
EDIT3 (take 2):
Here is the same example but with a log-scale x-axis. Note how instead of creating a second axis and manually setting its properties to match the first, I simply copyobj the axis, and delete its children.
%# create a plot as usual (x-axis is in the log-scale)
semilogx(logspace(0,5,100), cumsum(rand(100,1)-0.5))
xlabel('x'), ylabel('y'), title('text')
legend('plot')
%# capture handle to current figure and axis
hFig = gcf;
hAx1 = gca;
%# create a second transparent axis, as a copy of the first
hAx2 = copyobj(hAx1,hFig);
delete( get(hAx2,'Children') )
set(hAx2, 'Color','none', 'Box','on', ...
'XGrid','off', 'YGrid','off')
%# show grid-lines of first axis, style them as desired,
%# but hide its tick marks and axis labels
set(hAx1, 'XColor',[0.9 0.9 0.9], 'YColor',[0.9 0.9 0.9], ...
'XMinorGrid','on', 'YMinorGrid','on', 'MinorGridLineStyle','-', ...
'XTickLabel',[], 'YTickLabel',[]);
xlabel(hAx1, ''), ylabel(hAx1, ''), title(hAx1, '')
%# link the two axes to share the same limits on pan/zoom
linkaxes([hAx1 hAx2], 'xy');
%# Note that `gca==hAx1` from this point on...
%# If you want to change the axis labels, explicitly use hAx2 as parameter.
You should get the correct plot in your example with this code. However I think the x variable values you choose might be too close in the current figure size to show all the vertical lines (simply maximize the figure to see what I mean)...
To get a better idea of what each axis contains, here is a divided view where the plot on the left contains only the graphics rendered by hAx1, while the plot on right contains only the hAx2 components. Those two views are basically overlayed on top of each other in the final figure shown before.
Unfortunately, while the trick of over- or under-laying a second, gridded axes mostly works, Matlab does not render it properly when you save to a PDF file. This is because Matlab does not support transparency in PDFs.
One workaround is to simply use line to draw in the grid lines one by one:
for dir='XY';
ticks = get(gca, [dir 'Tick']);
lim = get(gca, [dir 'lim']);
for ii=1:length(ticks)
coord = ticks(ii);
for jj=1:9,
if jj==1 % major grid properties
color = [1 1 1]*0.9;
weight = 2;
else % minor grid properties
color = [1 1 1]*0.9;
weight = 1;
end
if jj*coord > lim(2)
continue
end
if dir=='X'
L = line((jj*coord)*[1 1], get(gca, 'ylim'), ...
'color', color, 'linewidth', weight);
else
L = line(get(gca, 'xlim'), (jj*coord)*[1 1], ...
'color', color, 'linewidth', weight);
end
uistack(L, 'bottom');
end
end
end
One downside of this approach is that it overwrites the tick marks and plot boundary box. A solution to this is to combine this approach with the trick of under-laying a second axes. Draw the fake grid on the underlying axes. This IS rendered properly in PDF:
While Amro is right that the minor grid's color is the same as that of the axis labels, you can always turn off the axis labels and overlay a second axes with transparent filling and set the labels on that in a different color. Here's a small example showing how:
plot(rand(10,1))
xTicks=get(gca,'xTick');
yTicks=get(gca,'ytick');
set(gca, 'XMinorGrid','on', 'YMinorGrid','on',...
'XColor','r', 'YColor','g','xticklabel',[],'yticklabel',[],...
'box','off')
h2=axes;
set(h2,'color','none','xtick',linspace(0,1,numel(xTicks)),'xticklabel',xTicks,...
'ytick',linspace(0,1,numel(yTicks)),'yticklabel',yTicks)
This lets you set independent colors for major and minor X and Y grid lines, without overwriting the outer box. Even better, subsequent legend() commands will pick up the plot lines, not the manually drawn grid lines.
The trick is to make copies of the axes, then reverse their order in the figure's drawing hierarchy. Each copy of the axes can then draw its own set of grid colors and styles.
This strategy is compatible with subplot() and print().
function gridcolor(majorX, majorY, minorX, minorY)
ax1 = gca; %# get a handle to first axis
%# create a second transparent axis, same position/extents, same ticks and labels
ax2 = copyobj(ax1,gcf);
ax3 = copyobj(ax1,gcf);
delete(get(ax2,'Children'));
delete(get(ax3,'Children'));
set(ax2, 'Color','none', 'Box','off','YTickLabel',[],'YTickLabel',[],...
'GridLineStyle', '-',...
'XGrid','on','YGrid','on',...
'XMinorGrid','off','YMinorGrid','off',...
'XColor',majorX,'YColor',majorY);
set(ax3,'Box','off','YTickLabel',[],'YTickLabel',[],...
'MinorGridLineStyle','-',...
'XGrid','off','YGrid','off',...
'XMinorGrid','on','YMinorGrid','on',...
'XColor',minorX,'YColor',minorY);
set(ax1, 'Color','none', 'Box','on')
handles = [ax3; ax2; ax1];
c = get(gcf,'Children');
for i=1:length(handles)
c = c(find(c ~= handles(i)));
end
set(gcf,'Children',[c; flipud(handles)]);
linkaxes([ax1 ax2 ax3]);
end
subplot(211);semilogx([1:4000]);gridcolor('r','g','c','b');
subplot(212);semilogx(([1:4000]).^-1);gridcolor('r','g','c','b');