Below is the user interface I have created to simulate LDPC coding and decoding
The code sequence is decoded iteratively by passing values between the left and right nodes through the connections.
The first thing it would be good to add in order to improve visualization is to add arrows to the connections in the direction of passing values. The alternative is to draw a bigger arrow at the top of the connection showing the direction.
Another thing I would like to do is displaying the current mathematical operation below the connection (in this example c * H'). What I don't know how to do is displaying special characters and mathematical symbols and other kinds of text such as subscript and superscript in the figure (for example sum sign and subscript "T" instead of sign ="'" to indicate transposed matrix).
I would be very thankful if anyone could point to any useful resources for the questions above or show the solution.
Thank you.
To add arrows, you can either use the built-in QUIVER, or, for more options, ARROW from the file exchange. Both of these have to be plotted into axes, so if you want a big arrow on the top, you have to create an additional set of axes above the main axes.
As far as I know, you cannot use TeX or LaTeX symbols in text uicontrols. However, you can use them in axes labels. Thus, I suggest that you add an XLabel to the axes, for example
xlabel('\sigma c*H_T')
or (note the $-signs required for LaTeX)
xlabel('$\sum c*H_T$','interpreter','latex')
EDIT
I hadn't mentioned the use of text (as suggested by #gnovice and #YYC) because I thought it wasn't possible to place text outside of the axes. It turns out that I was wrong. text(0.5,-0.2,'\Sigma etc.') should work fine as well. I guess the only advantage of using 'xlabel' would be that you can easily add and position the axes label during GUI creation.
In regards to the 1st question, annotation (http://www.mathworks.com/access/helpdesk/help/techdoc/ref/annotation.html) might be an alternative solution.
In regards to the 2nd question, try text property in Matlab Help.
Search "Character Sequence" for the special characters; search "Specifying Subscript and Superscript Characters" for the subscript and superscript.
For drawing the arrow, I would go Jonas' suggestion arrow.m by Erik Johnson on the MathWorks File Exchange. It's the easiest way I've found to create arrows in figures.
For creating text with symbols, you can use the function TEXT. It lets you place text at a given point in an axes, and you can use the 'tex' (default) or 'latex' options for the 'Interpreter' property to get access to different symbols. For example, this places the text you want at the point (0,0) using 'latex' as the interpreter:
hText = text(0,0,'$\sum c*H_T$','Interpreter','latex');
The variable hText is a handle to the text object created, which you can then use with the SET command to change the properties of the object (string, position, etc.).
Related
I am trying this example:
http://www.mathworks.com/help/symbolic/latex.html
Let's say I wanted to resize those labels. How? I can't figure out any LaTeX code, and 'fontsize' does not do the trick.
This hits a sore spot when it comes to Matlab's support for (or use of) Latex. The normal font-size commands from Latex aren't available. (In Latex normally you'd just say \Large{Text ... $x$} or even \normalsize ....)
To do this in a Matlab plot you can add fontsize spec at the end
title(['For $x$ and ...'], 'Interpreter', 'latex', 'fontsize', 14)
For more discussion and how to change font type as well see this post. Note that there are not so many fonts readily available in Matlab. To preserve sanity I'd keep this kind of tweaking to the minimum.
There is another method that will work anywhere in Matlab where you can use Latex -- in any text, in the middle of a string, etc: You can drop to Latex's lower level font specification.
title(['\fontsize{15}{0}\selectfont For $x$ and ...'], 'Interpreter', 'latex')
The first command \fontsize{}{} specifies the font, the second one \selectfont actually changes it for the rest of the text. When you want to switch to a different font, even mid-string, you again issue \fontsize{12}{0}\selectfont and you have that font size after that point. The only thing you need to change is the size (I used 15 and 12 as examples), the rest is boilerplate (for this purpose).
See what these things mean and more discussion in this post. For far more detail on fonts in Matlab see this article. For how to change fonts across the whole document see this post.
There are yet other ways but it gets progressively trickier and this should be enough. Probably the best advice is to set it once for the whole document. That also makes sense typesetting-wise.
Note. The font command of the second example must be given outside of math mode. Latex has two major modes, text and math. To make it go to 'math mode', where it processes everything as it were math symbols, you put a $, or $$. (There are yet many other ways, but in Matlab's strings this is all you'll ever use.) When you want it to go back to typesetting text normally, you end math mode with another $, or $$. All math is in between $...$, everything else is normal text.
This is some text, now typeset some math: $y = x^2$ ... back to text.
The font commands do not work in math mode but need be given outside the $...$. They will apply to any following math as well. In a plot command we'd say
ylabel(['\fontsize{16}{0}\selectfont $\dot{x}$'], 'interpreter','latex');
Here is the line that worked:
ylabel('$x_e, x_c$', 'interpreter','latex', 'fontsize', 32);
Obviously, between the dollar signs can be whatever appropriate LaTeX expression desired.
use Microsoft Word to edit an equation with underbrace. The line is as follows:
\underbrace(ab+cdf-edf=9dc/ereat+asdfdgg-asfeefe-eafdgahty+atataeaattrat)
The problem is the symbol for underbrace is very flat, looking like a line with the downward pointing part too small to see. Is there a way to make it larger (e.g., is there a way to stretch the underbrace VERTICALLY)? The size of underbrace is set automatically in Latex and looks fine. But in Microsoft Word, the default just does not look especially when you have a long equation. I am not sure if there is a setting allowing you to change it. Many thanks! Gene
I am drawing text in a PDF page using iTextSharp, and I have two requirements:
1) the text needs to be searchable by Adobe Reader and such
2) I need character-level control over where the text is drawn.
I can draw the text word-by-word using PdfContentByte.ShowText(), but I don't have control over where each character is drawn.
I can draw the text character-by-character using PdfContentByte.ShowText() but then it isn't searchable.
I'm now trying to create a PdfTextArray, which would seem to satisfy both of my requirements, but I'm having trouble calculating the correct offsets.
So my first question is: do you agree that PdfTextArray is what I need to do, in order to satisfy both of my original requirements?
If so, I have the PdfTextArray working correctly (in that it's outputting text) but I can't figure out how to accurately calculate the positioning offset that needs to get put between each pair of characters (right now I'm just using the fixed value -200 just to prove that the function works).
I believe the positioning offset is the distance from the right edge of the previous character to the left edge of the new character, expressed in "thousandths of a unit of text space". That leaves me two problems:
1) How wide is the previous character (in points), as drawn in the specified font & height? (I know where its left edge is, since I drew it there)
2) How do I convert from points to "units of text space"?
I'm not doing any fancy scaling or rotating, so my transformation matrices should all be identity matrices, which should simplify the calculations ...
Thanks,
Chris
I am desiging a simple GUI application in Matlab using GUIDE.
I am displayed a number of axis - and I would like to add some simple design elements to make the interface clearer. I would like to draw a colored rectangle around an axis (seperate from the axis)... there are two such axes, each displaying details of some things shown in a third plot, and I would like this color clue to link the details to the overview.
So is it possible to add simple geometric shape objects to a Matlab GUI? I don't see anything but controls in GUIDE but perhaps its possible to add them manually with an explicit command?
It is generally difficult to draw any random shape. Except Square & rectangle, for which you can create panels and change the properties like BorderWidth and HighlightColor.
Since MATLAB GUI is based on Java, you can create any object in MATLAB GUI which can be created in Java. You can refer to this website [1] for further learning.
[1] http://undocumentedmatlab.com/matlab-java-book/
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)