When I make a figure in Matlab, with a legend and a rectangle that touches the y axis (strange, I know) upon exporting the figure to eps (or pdf) I've noticed that the rectangle obtains the line-style of the last line drawn (rather than what the rectangle was drawn with)
This behaviour also occurs for rectangles drawn after the one that touches the axis...
This doesn't happen if the rectangle is drawn before the legend is created....
Needless to say, it took me half a day to create a minimal example:
clf
L=plot(X,sin(X),'--');
legend(L,'sin(x)')
rectangle('position',[0.001,.1,.7,.7])
rectangle('position',[0,.5,.6,.7])
rectangle('position',[0.001,.3,.5,.7])
%legend(L,'sin(x)')
On the screen the 3 rectangle have solid lines, as they should. but once they are exported, the result has the last two with dashed lines (like the sin(x)). If the legend command is done later (as in the commented out line), everything works as it should....
Is this a feature or a bug?
This is not a feature. I am submitting this to development.
You found a workaround that works with minimal code gymnastics. I would document it in your code so someone does not change it unknowingly and move on.
If you are open to other output formats, notice this is not an issue with formats that use an output filter of MATLAB.
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/print.html
(Graphic Format Files section, right column in table)
-Doug, Advanced Support at MathWorks dealing with graphical issues.
Related
I am trying to get better quality phase plots of complex functions made with the Complex Function Explorer of E. Wegert CFE. For this purpose I apply the Matlab anti-aliasing function myaa.m to the phase plots that are made with the CFEGUI.m. For the example screenshot of the result window below I used the setting myaa([8 8]) in the Matlab command window which means that the supersampling enlarge the figure 8x and then downscale it to 1/8 to get the original h x w.
As one can see the window of the figure has no operation icons or menu options for save or print. My question is what to do with such a figure (beside making screenshots)? Can I somehow use export-fig to save such a figure or load it in an image array and if yes, how?
It is also possible to use the setting myaa([8 1]) which results in a very large figure window that is larger than my screen (and has the unpleasant attribute that it can not be moved). It would be even better if such a whole figure could be saved (not only the visible part).
You can use getframe to grab current figure information in pixels.
However, while I do not know how this affects you, notice that MATLAB versions above 2014b (included) have already anti-aliasing. The code you linked seem to be from 2008, I am not 100% sure if it has become obsolete now.
Since version R2014b, MATLAB now renders graphics nicely anti-aliased (finally!)
However, this causes a glitch in the way it displays some of my figures. If I plot a line, use hold on and then plot another line in exactly the same place with a different colour, the line appears in a mottled combination of both colours. In the past, the line would simply appear as the last colour that was plotted in that location.
Here's an example of a trace in blue, with some sections (the steeper bits) showing a green line. In previous MATLAB versions, the green lines would be continuous, but now some of the blue line shows through.
Is there a neat way to work around this in the new version, or do I have to ensure that I remove any existing lines before plotting in the same place?
When overplotting, the new anti aliasing plots can have some bleed through, try
set(gcf,'GraphicsSmoothing','off')
To see if it restores the functionality you're used to.
Ref:
http://www.mathworks.com/matlabcentral/answers/157758-how-do-i-turn-off-antialiasing-in-matlab-r2014b
I am currently using the fill command in MATLAB to create a graph of boxes that were created using the 'fill' command (the actual code is based off this StackOverflow Question.
My issue is that the boxes that I create do not have "corners." I am attaching a PNG that illustrates the issue. Note that you have to look a little carefully since the image was heavily rendered, though in this example my arrows also look weird since they don't have edges either)
I am wondering if anyone has an idea of what might be going wrong? The boxes appear this way immediately after I use the fill command, which has the following structure:
fill(X,Y,MyFaceColor,'FaceAlpha',0.5,'EdgeColor', MyEdgeColor,'LineStyle','','LineWidth',box_line_width,'EdgeAlpha',1)
The function fill appears to leave space for corner markers if they are not explicitly defined. Hence, calling fill with the marker property will solve your problem. However, since markers and linewidths seem to work on different scales, you will have to play around with the marker size to get smooth edges.
Example:
fill(X,Y,'r','FaceAlpha',0.5,'EdgeColor', 'k',...
'LineWidth', 5,'EdgeAlpha',1 , 'marker', '.', 'markersize', 15)
A figure file is saved. When several lines are intersected, I want to make one of the line visible. How should I modify the different layer of the lines without re-plotting the figure?
Use uistack (see doc). For example, after:
figure
hold on
hblue=plot([1 2],[3 4],'b','LineWidth',5);
hred=plot([1 2],[4 3],'r','LineWidth',5);
the red line is on top (and the blue line would not be seen if the the red line covered it). Then, if you use uistack(hblue,'top'), the blue line is brought to the top. Other options to reorder plots, instead of top, are up, down, and bottom. You can optionally specify the number of steps up or down (e.g. uistack(h,'up',2) to move a handle two layers up - though no need in my simple example).
If, as you say, the 'figure file is saved', and you don't have the handles for the plots, (hblue and hred in my example), after loading the plot, you can get the handles using get(gca,'children').
If I understood you correctly, try to use hold on before plotting...
Given an image consisting of black lines (a few pixels wide) on white background, what is a good way to find the coordinates along the the lines, say for every 10th pixel or so? I am considering using PIL for the task, but other python or java-based libraries would also be OK.
Ideally the coordinates would point to the middle of the line, but as the lines are narrow, it's enough that they point somewhere inside the line.
A very short line or a point should be identified with at least one coordinate.
Usually, Hough transformation is used to find lines. It gives you the parameters describing the line (which can be transformed easily between different representations), and you can sample this function to get your sample points. See http://en.wikipedia.org/wiki/Hough_transform and https://stackoverflow.com/questions/tagged/hough-transform+python
I only found this http://coding-experiments.blogspot.co.at/2011/05/ellipse-detection-in-image-by-using.html implementation in python, which actually searches for ellipses.