I would like to use Simulink to draw a signal path, without any functionality.
So, how do I disable all checks? Connect what ever I want, and name it with any names/symbols/characters? Is this possible?
In my opinion LibreOffice Draw or Microsoft Visio are not as nice for this purpose.
Simulink has all the blocks I need.
As already mentioned in the comments, Simulink is just not made for that. But you can use external applications like Inkscape (Open Source) or Adobe Illustrator (maybe MS Visio works as well) etc. All you need is a vector graphic of your Simulink Model.
You can get that for example by:
print -sMyModelname -dpdf -r300 model.pdf
or more generic:
modelname = 'myModel';
format = 'pdf'; %// or 'svg' or whatever
resolution = '300'; %// vector graphics do not really have a resolution,
%// but this way linewidth and canvas size are determined
filename = 'myModel.pdf';
print( ['-s' modelname], ['-d' format] , ['-r' resolution] , filename );
Now you easily can connect the blocks with splines as you wish and changed block annotations.
Apart from that: in a serious scientific context there is almost now way around Latex+Tikz.
Old post, still relevant.
Take for example Simscape or the older Power Systems toolbox.
They provide in/out ("physical") pins, allowing arbitrary connection of blocks, without classic Simulink checks if outputs are connected to outputs.
Without too much imagination, checks common in all "physical" toolboxes like
set_param(modelName, 'PhysicalModelingChecksum', '101269080');
are good for more than data integrity.
Someone else able to implement arbitrary connections, anyone?
Related
I am currently working with multibody mechanical systems using the MultiBody library included in the standard Modelica distribution.
I need to implement a switch between flanges, in order to select position or force control for a given joint.
model FlangeSwitch "Switch between flanges"
Modelica.Mechanics.Translational.Interfaces.Flange_a flange_a_1;
Modelica.Mechanics.Translational.Interfaces.Flange_b flange_b_1;
Modelica.Mechanics.Translational.Interfaces.Flange_a flange_a_2;
Modelica.Mechanics.Translational.Interfaces.Flange_b flange_b_2;
Modelica.Mechanics.Translational.Interfaces.Flange_a flange_a_exit;
Modelica.Mechanics.Translational.Interfaces.Flange_b flange_b_exit;
Modelica.Blocks.Interfaces.BooleanInput u;
equation
if u then
flange_a_exit = flange_a_2;
flange_b_exit = flange_b_2;
else
flange_a_exit = flange_a_1;
flange_b_exit = flange_b_1;
end if;
end FlangeSwitch;
But this approach does not work, the system is not balanced: 10 equations and 12 variables.
Is there any way to do this?
I don't think a Modelica tool will allow this operation (even if you have a balanced model), as it would potentially result in a variable structure system. Which is something Modelica does not support at the moment. See a nice introduction here: https://www.modelica.org/events/modelica2017/proceedings/html/submissions/ecp17132291_Stuber.pdf
Without fully knowing the application you could try two approaches:
Use a model that emulates a rotational clutch, like the Modelica.Mechanics.Translational.Components.Brake with an activated parameter useSupport. This way you can generate a "controllable mechanical connection" for connecting either of the flanges to the support connector. If I read your code correctly you should connect flange_a_2 to the support and the flange_a_exit to either flange_a or flange_b. When activating the brake via the RealInput there will be a mechanical connection.
The second thing you can try is to measure either position or force (which of both you want to apply by a sensor Modelica.Mechanics.Translational.Sensors.PositionSensor and then apply it using the respective source, which in this case would be Modelica.Mechanics.Translational.Sources.Position. Switching between the sources could then be done by switching the Real signals instead of the physical connectors. Mind that is could generate jumps in positions when applying positions directly.
The link you posted is related to non-phyiscal connectors, which are less restrictive compared to the physical connectors. So comparing the two solutions should be done very carefully.
Switching from position as an input to force as an input would require the system of equations to be rebuilt when executing this switch. This will not be possible with current generation Modelica. You will need to find a solution that is based on the same input for the whole simulation.
Would it be enough to initialize position in a way that the system starts the simulation in the point where you want to move it to first (using the Position Source)? What you loose is the movement of the system to this position.
I thought this should be a simple task, I just can't find the way to do it:
I am using 'imregister' (MATLAB) to register two medical X-ray images.
To ensure I get the best registration outcome as possible, I use some image processing techniques such as contrast enhancement, blackening of objects that are different between images and even cropping.
The outcome of this seems to be quite satisfying.
Now, I want to perform the exact same registaration on the original images, so that I can display the two ORIGINAL images automatically in alignment.
I think that an output parameter such as tform serves this purpose of performing a certain registration on any two images, but unfortunately 'imregister' does not provide such a parameter, as far as I know.
It does provide as an output the spatial referencing object R_reg which might be the answer, but I still haven't figured out how to use it to re-preform the registration.
I should mention that since I am dealing with medical X-ray images on which non of the feature-detecting algorithms seem to work well enough to perform registration, I can only use intensity-based (as opposed to feature-based) registration, and therefore am using 'imregister'.
Does anyone know how I can accomplish this?
Thanks!
Noga
So to make an answer out of my comment, there are 2 things you can do depending on the Matlab release you are using:
Option 1: R2013a and earlier
I suggest modifying the built-in imregister function by forcing tform to be an output and save that function under another name.
For example:
function [movingReg,Rreg,tform] = imregister2(varargin)
save that, add it to your path and you're good to go. If you type edit imregister you will notice that the 1st line calls imregtform to get the geometric transformation required, while the last line calls imwarp, to apply that geometric transformation. Which leads us to Option 2.
Option 2: R2013b and later
Well in that case you can directly use imregtform to get the tform object and then use imwarpto apply it. Easy isn't it?
Hope that makes things clearer!
I have some programs written in Matlab that I need to run several times for some reasons (debugging, testing with different input, etc...)
But, there are a lot's of graphs that are plotted by the programs and its various functions such that everytime I run the program, I have to wait for all the graphs to be displayed, which is very annoying and time consuming (especially when you are working with a small laptop).
After the program is executed, I close them with a close all.
So my question is:
Is there a way to disable all plots/figures/graphs in Matlab? either in the options, or by executing a certain code like disable plot and enable plot to ensure that no figures are being displayed.
I know that I can just browse the code and comment the plotting part, but I don't want to forget to uncomment.
Try some combination of the two commands:
set(gcf,'Visible','off') % turns current figure "off"
set(0,'DefaultFigureVisible','off'); % all subsequent figures "off"
The second one, if you put it near the beginning of your program, might do the trick for you. Of course, it is still creating the plots, which might be undesirable for computation time and/or RAM issues.
This is a classic reason to avoid Matlab when one can. It fosters bad programming design. To solve this problem correctly, you should create something that lets you "flip a switch" at the highest level of your program and control whether plots show or do not show. Perhaps it even has gradations of the show/don't show option so you can select different types of plots that do/do not show depending on what diagnostics you are running.
Ideally, you'd want this "flip a switch" creation to be a class that has access to visibility and plot functions of other objects. But because interactive object-orientation is so cumbersome in Matlab, it's often not worth the effort to develop such a solution, and most people don't think about this design aspect from the outset of their project.
Matlab would encourage someone to solve this by making flag variables like "isPlotVisible" or something, and creating functions that always accept such flags. I agree this is a bad design.
You could run matlab from the command line with:
matlab -nojvm
but then you don't get the GUI at all. Alternatively, you could write a file 'plot.m':
function h = plot(varargin)
h = [];
end
which doesn't do anything. If this is in the working directory (or somewhere else near the top of the path), then plot will call your function instead of the 'real' plot. You'd need to do the same from any other graphing functions you call.
The closest way I know of 'turning off plotting' would be a folder of such functions that you can add to the path to disable plotting, and remove to enable.
The previous methods are fine, but an easy and good habit to take is to use a "on/off parameter". So basically, at the beginning of your code, you can add something like:
DisplayFigure = 1; %1 = display, 0 = no display
After that, add "if DisplayFigure == 1 ... end" for all your plotting related commands, where the commands should be inside the if statement (the ... above). Hence you won't even compute the plots, which will save you a lot of time and memory. You just have to change the value of the variable "DisplayFigure" to plot or not the figures.
I am implementing some head tracking and I get 2 matrices of horizontal velocities. (A vector field decomposed into vertical and horizontal velocities). For each of these matrices I do some math to calculate the actual head tracking.
My question is, is there a way to do that math (which is a set of blocks) on both matrices without copying the math blocks onto each signal?
It's hard to explain so here's a screen shot of my model:
You can see that the "complex to real-imag" block has 2 outputs (this is the little one in the middle). The mean block and the integrator circuit then calculate the head velocity and position for the real matrix (horizontal position). I want to do exactly the same routine on the imaginary matrix (vertical direction). Obviously I can just copy the blocks, but surely there must be a better way of doing it? In a way I'm looking for an analogue of a loop in "normal programming" like C or something, where a block of code is executed several times on different inputs.
You can create a Library in Simulink that contains code you can reference multiple times.
Go to File -> New -> Library. In the model window that opens, you can create any number of subsystems with whatever code you want. Then, just drag a subsystem from the library into your model. The subsystem will now appear in your model with a little arrow icon in the lower left. This indicates that the subsystem in the model is a link. You can drag as many instances of the library subsystem into your model as you wish, just as you can call a function as many times as you wish in any other programming language.
If you right-click on the subsystem in your model, you can select "Link Options -> Go To Library Block" to get back to the library. You can make changes in your model and propogate them back to the library as well.
One way to easily reuse a set of blocks is to create a subsystem out of them. In your case, you can create a subsystem by grouping existing blocks, then simply copy and paste your subsystem to use it for your imaginary output.
Although potentially more complicated, you could also look into using mux signals to avoid having to copy parts of your model.
Although many of you will have a decent idea of what I'm aiming at, just from reading the title -- allow me a simple introduction still.
I have a Fortran program - it consists of a program, some internal subroutines, 7 modules with its own procedures, and ... uhmm, that's it.
Without going into much detail, for I don't think it's necessary at this point, what would be the easiest way to use MATLAB's plotting features (mainly plot(x,y) with some customizations) as an interactive part of my program ? For now I'm using some of my own custom plotting routines (based on HPGL and Calcomp's routines), but just as part of an exercise on my part, I'd like to see where this could go and how would it work (is it even possible what I'm suggesting?). Also, how much effort would it take on my part ?
I know this subject has been rather extensively described in many "tutorials" on the net, but for some reason I have trouble finding the really simple yet illustrative introductory ones. So if anyone can post an example or two, simple ones, I'd be really grateful. Or just take me by the hand and guide me through one working example.
platform: IVF 11.something :) on Win XP SP2, Matlab 2008b
The easiest way would be to have your Fortran program write to file, and have your Matlab program read those files for the information you want to plot. I do most of my number-crunching on Linux, so I'm not entirely sure how Windows handles one process writing a file and another reading it at the same time.
That's a bit of a kludge though, so you might want to think about using Matlab to call the Fortran program (or parts of it) and get data directly for plotting. In this case you'll want to investigate Creating Fortran MEX Files in the Matlab documentation. This is relatively straightforward to do and would serve your needs if you were happy to use Matlab to drive the process and Fortran to act as a compute service. I'd look in the examples distributed with Matlab for simple Fortran MEX files.
Finally, you could call Matlab from your Fortran program, search the documentation for Calling the Matlab Engine. It's a little more difficult for me to see how this might fit your needs, and it's not something I'm terribly familiar with.
If you post again with more detail I may be able to provide more specific tips, but you should probably start rolling your sleeves up and diving in to MEX files.
Continuing the discussion of DISLIN as a solution, with an answer that won't fit into a comment...
#M. S. B. - hello. I apologize for writing in your answer, but these comments are much too short, and answering a question in the form of an answer with an answer is ... anyway ...
There is the Quick Plot feature of DISLIN -- routine QPLOT needs only three arguments to plot a curve: X array, Y array and number N. See Chapter 16 of the manual. Plus only several additional calls to select output device and label the axes. I haven't used this, so I don't know how good the auto-scaling is.
Yes, I know of Quickplot, and it's related routines, but it is too fixed for my needs (cannot change anything), and yes, it's autoscaling is somewhat quircky. Also, too big margins inside the graf.
Or if you want to use the power of GRAF to setup your graph box, there is subroutine GAXPAR to automatically generate recommended values. -2 as the first argument to LABDIG automatically determines the number of digits in tick-mark labels.
Have you tried the routines?
Sorry, I cannot find the GAXPAR routine you're reffering to in dislin's index. Are you sure it is called exactly like that ?
Reply by M.S.B.: Yes, I am sure about the spelling of GAXPAR. It is the last routine in Chapter 4 of the DISLIN 9.5 PDF manual. Perhaps it is a new routine? Also there is another path to automatic scaling: SETSCL -- see Chapter 6.
So far, what I've been doing (apart from some "duck tape" solutions) is
use dislin; implicit none
real, dimension(5) :: &
x = [.5, 2., 3., 4., 5.], &
y = [10., 22., 34., 43., 15.]
real :: xa, xe, xor, xstp, &
ya, ye, yor, ystp
call setpag('da4p'); call metafl('xwin');
call disini(); call winkey('return');
call setscl(x,size(x),'x');
call setscl(y,size(y),'y')
call axslen(1680,2376) !(8/10)*2100 and 2970, respectively
call setgrf('name','name','line','line')
call incmrk(1); call hsymbl(3);
call graf(xa, xe, xor, xstp, ya, ye, yor, ystp); call curve(x,y,size(x))
call disfin()
end
which will put the extreme values right on the axis. Do you know perhaps how could I go to have one "major tick margin" on the outside, as to put some area between the curve and the axis (while still keeping setscl's effects) ?
Even if you don't like the built-in auto-scaling, if you are already using DISLIN, rolling your own auto-scaling will be easier than calling Fortran from MATLAB. You can use the Fortran intrinsic functions minval and maxval to find the smallest and largest values in the data, than write a subroutine to round outwards to "nice" round values. Similarly, a subroutine to decide on the tick-mark spacing.
This is actually not so easy to accomplish (and ideas to prove me wrong will be gladly appreciated). Or should I say, it is easy if you know the rough range in which your values will lie. But if you don't, and you don't know
whether your values will lie in the range of 13-34 or in the 1330-3440, then ...
... if I'm on the wrong track completely here, please, explain if you ment something different. My english is somewhat lacking, so I can only hope the above is understandable.
Inside a subroutine to determine round graph start/end values, you could scale the actual min/max values to always be between 1 and 10, then have a table to pick nice round values, then unscale back to the correct range.
--
Dump Matlab because its proprietary, expensive, bloated/slow and codes are not easy to parallelize.
What you should do is use something on the lines of DISLIN, PLplot, GINO, gnuplotfortran etc.